benchmark_manifest.json

{
  "schema_version": 1,
  "benchmark_name": "pcve_benchmark_v1",
  "prompts_schema": {
    "flavors": [
      "vague.zh",
      "vague.en",
      "quantitative.zh",
      "quantitative.en"
    ],
    "notes": "quantitative names the number the edit turns on: for SET the multiple of the baseline the property moves to (5x, 1/4), for ADD the division point of the line between two named objects (the midpoint, or the quarter point nearer one of them). vague is direction-only (increase/decrease/activate/deactivate/change), and for ADD a relative position (closer to one endpoint, or midway) with no number. Both flavours also state when the edit takes effect: quantitative names the frame, vague places it in the clip (from the start / early / about halfway / late)."
  },
  "properties_vocab": [
    "mass",
    "friction",
    "restitution",
    "initial_velocity",
    "presence"
  ],
  "scenes": [
    "air_hockey_chain",
    "ball_block",
    "ball_box_rebound",
    "ball_carpet_climb",
    "bouncing_ball",
    "bowling",
    "car_gap_jump",
    "car_ramp_climb",
    "curling_collision",
    "dining_chain",
    "domino_chain",
    "mahjong_dice",
    "picnic_apple_ball",
    "pool_collision",
    "ramp_collision",
    "table_drop_collision",
    "table_marble_collision",
    "tennis_flight",
    "toy_car_ball",
    "twin_ramp_collision"
  ],
  "counts": {
    "scenes": 20,
    "sources": 20,
    "edits": 129,
    "by_property": {
      "friction": 21,
      "initial_velocity": 26,
      "mass": 32,
      "presence": 37,
      "restitution": 13
    },
    "by_kind": {
      "SET": 92,
      "DELETE": 30,
      "ADD": 7
    },
    "by_timing": {
      "partway": 12,
      "whole_clip": 117
    }
  },
  "sources": [
    {
      "global_id": "air_hockey_chain/air_hockey_chain_baseline",
      "scene": "air_hockey_chain",
      "case_id": "air_hockey_chain_baseline",
      "video": "scenes/air_hockey_chain/cases/air_hockey_chain_baseline/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "蓝色球槌沿桌面被推向红色球槌,撞上后停在原地、把速度交出去;红色球槌照样把速度交给白色球槌,白色球槌再把这股推力带向近端围板。",
          "en": "The blue mallet is pushed along the table into the red mallet, stops where it hits and hands its speed on; the red mallet passes it to the white mallet the same way, and the white one carries the push on to the near rail."
        },
        "quantitative": {
          "zh": "三个相同的球槌成一列排开,间距 0.60 m。蓝色球槌以 0.8 m/s 被推向红色球槌并停住,红色球槌又撞上白色球槌后停住。三个球槌的行程都在 0.49 m 上下。",
          "en": "Three identical mallets sit in a line 0.60 m apart. The blue mallet is pushed at 0.8 m/s into the red mallet and stops there; the red mallet goes on into the white mallet and stops in turn. All three end up having travelled about the same 0.49 m."
        }
      },
      "editable_objects": [
        {
          "object_id": "blue_mallet",
          "zh": "蓝色球槌",
          "en": "the blue mallet",
          "properties": [
            "friction",
            "initial_velocity",
            "mass",
            "restitution"
          ],
          "can_delete": true
        },
        {
          "object_id": "red_mallet",
          "zh": "红色球槌",
          "en": "the red mallet",
          "properties": [
            "friction",
            "mass",
            "restitution"
          ],
          "can_delete": true
        },
        {
          "object_id": "white_mallet",
          "zh": "白色球槌",
          "en": "the white mallet",
          "properties": [
            "friction",
            "mass",
            "restitution"
          ],
          "can_delete": true
        }
      ]
    },
    {
      "global_id": "ball_block/ball_block_baseline",
      "scene": "ball_block",
      "case_id": "ball_block_baseline",
      "video": "scenes/ball_block/cases/ball_block_baseline/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "红球滚过地板撞上木块,把木块推走一段后木块停下;红球随后越过木块继续前进,片尾时仍在缓慢滚动。",
          "en": "The ball rolls across the floor into the wooden block, shoves it along until the block stops, then carries on past it and is still rolling slowly when the clip ends."
        },
        "quantitative": {
          "zh": "红球以 6 m/s 滚入,第 13 帧撞上木块,把木块推出 1.47 m 后木块停下。红球越过木块继续前进,全程 4.17 m,4 秒片尾时仍在缓慢滚动。",
          "en": "The ball rolls in at 6 m/s, reaches the wooden block on frame 13 and shoves it 1.47 m across the floor before the block comes to rest. The ball carries on past it, covering 4.17 m in all, and is still rolling slowly when the 4 s clip ends."
        }
      },
      "editable_objects": [
        {
          "object_id": "ball",
          "zh": "红球",
          "en": "the ball",
          "properties": [
            "friction",
            "initial_velocity",
            "mass",
            "restitution"
          ],
          "can_delete": false
        },
        {
          "object_id": "wood_block",
          "zh": "木块",
          "en": "the wooden block",
          "properties": [
            "friction",
            "mass",
            "restitution"
          ],
          "can_delete": true
        }
      ]
    },
    {
      "global_id": "ball_box_rebound/ball_box_rebound_baseline",
      "scene": "ball_box_rebound",
      "case_id": "ball_box_rebound_baseline",
      "video": "scenes/ball_box_rebound/cases/ball_box_rebound_baseline/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "星星球滚向玩具箱的正面板,斜着弹开后撞上小足球并把它撞开。片尾前两球都已静止。",
          "en": "The star ball is rolled at the toy chest's front panel, comes off it at an angle, and goes on to hit the little football and knock it clear. Both have settled before the clip ends."
        },
        "quantitative": {
          "zh": "星星球以 2.60 m/s 滚向玩具箱的正面板,斜着弹开后撞上小足球,把它撞开 0.30 m。星星球相对起点移动 1.10 m,片尾前两球都已静止。",
          "en": "The star ball is rolled at 2.60 m/s at the toy chest's front panel, comes off it at an angle, and goes on to hit the little football, knocking it 0.30 m clear. The star ball ends 1.10 m from where it started; both have settled before the clip ends."
        }
      },
      "editable_objects": [
        {
          "object_id": "ball_a",
          "zh": "星星球",
          "en": "the star ball",
          "properties": [
            "friction",
            "initial_velocity",
            "mass",
            "restitution"
          ],
          "can_delete": false
        },
        {
          "object_id": "ball_b",
          "zh": "小足球",
          "en": "the little football",
          "properties": [
            "friction",
            "mass",
            "restitution"
          ],
          "can_delete": true
        }
      ]
    },
    {
      "global_id": "ball_carpet_climb/ball_carpet_climb_baseline",
      "scene": "ball_carpet_climb",
      "case_id": "ball_carpet_climb_baseline",
      "video": "scenes/ball_carpet_climb/cases/ball_carpet_climb_baseline/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "排球滚过裸地板,上到与地面齐平的地毯上,被绒毛拖停在茶几旁。",
          "en": "The volleyball is rolled across bare floor onto a rug lying flush with it, and the pile drags it to a stop beside the coffee table."
        },
        "quantitative": {
          "zh": "排球以 2.05 m/s 滚过裸地板,上到与地面齐平的地毯上,被绒毛拖停,全程移动 1.09 m,停在茶几旁。",
          "en": "The volleyball is rolled at 2.05 m/s across bare floor, reaches the flush rug, and is brought to rest by the pile after 1.09 m of travel in all, beside the coffee table."
        }
      },
      "editable_objects": [
        {
          "object_id": "ball",
          "zh": "排球",
          "en": "the volleyball",
          "properties": [
            "friction",
            "initial_velocity",
            "mass",
            "restitution"
          ],
          "can_delete": false
        }
      ]
    },
    {
      "global_id": "bouncing_ball/bouncing_ball_baseline",
      "scene": "bouncing_ball",
      "case_id": "bouncing_ball_baseline",
      "video": "scenes/bouncing_ball/cases/bouncing_ball_baseline/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "红球带着轻微的水平初速落下,触地后一路弹跳着横穿房间。弹跳逐次变小,片尾时仍在运动。",
          "en": "The red ball is dropped with a gentle sideways push, meets the floor and bounces its way across the room. The bounces get smaller and it is still moving when the clip ends."
        },
        "quantitative": {
          "zh": "红球从 1.57 m 高处释放,带 0.5 m/s 的水平初速,第 13 帧首次触地,之后一路弹跳着横穿房间。弹跳逐次衰减,片尾时球仍在运动。",
          "en": "The red ball is released from 1.57 m with a gentle 0.5 m/s horizontal push, first meets the floor on frame 13, and bounces its way across the room. The chain decays over the clip and the ball is still moving when it ends."
        }
      },
      "editable_objects": [
        {
          "object_id": "ball",
          "zh": "红球",
          "en": "the red ball",
          "properties": [
            "friction",
            "initial_velocity",
            "mass",
            "restitution"
          ],
          "can_delete": false
        }
      ]
    },
    {
      "global_id": "bowling/bowling_baseline",
      "scene": "bowling",
      "case_id": "bowling_baseline",
      "video": "scenes/bowling/cases/bowling_baseline/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "保龄球滚下球道撞进保龄球瓶阵,从瓶阵正面穿过并继续前行,球瓶被撞散。",
          "en": "The bowling ball is rolled down the lane into the bowling pin set, ploughs through the front of the formation and carries on past it while the pins scatter."
        },
        "quantitative": {
          "zh": "3 kg 的保龄球以 8 m/s 滚下球道撞进保龄球瓶阵,从瓶阵正面穿过,全程 14.35 m。球瓶被撞散,三只加起来移动 6.67 m,其中头瓶一只就占了 4.08 m。",
          "en": "The bowling ball, 3 kg, is rolled at 8 m/s down the lane into the bowling pin set. It ploughs through the front of the formation and carries 14.35 m in all; the pins scatter for 6.67 m of travel between them, the head pin alone accounting for 4.08 m."
        }
      },
      "editable_objects": [
        {
          "object_id": "ball",
          "zh": "保龄球",
          "en": "the bowling ball",
          "properties": [
            "friction",
            "mass",
            "restitution"
          ],
          "can_delete": false
        },
        {
          "object_id": "pins",
          "zh": "保龄球瓶",
          "en": "the bowling pin set",
          "properties": [
            "friction",
            "mass",
            "restitution"
          ],
          "can_delete": false
        }
      ]
    },
    {
      "global_id": "car_gap_jump/car_gap_jump_baseline",
      "scene": "car_gap_jump",
      "case_id": "car_gap_jump_baseline",
      "video": "scenes/car_gap_jump/cases/car_gap_jump_baseline/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "玩具车被推过书堆,越过前方的缺口,正面朝上落在对面桌子上并停下。",
          "en": "The toy car is pushed across a book stack, clears the gap beyond it, and lands upright on the far table where it comes to rest."
        },
        "quantitative": {
          "zh": "玩具车被推过书堆,越过缺口,正面朝上落在对面桌子上,相对起点移动 1.07 m,停在 x=+0.87。",
          "en": "The toy car is pushed across the book stack, clears the gap, and lands upright on the far table, coming to rest 1.07 m from where it set off, at x=+0.87."
        }
      },
      "editable_objects": [
        {
          "object_id": "car",
          "zh": "玩具车",
          "en": "the toy car",
          "properties": [
            "friction",
            "initial_velocity"
          ],
          "can_delete": false
        }
      ]
    },
    {
      "global_id": "car_ramp_climb/car_ramp_climb_baseline",
      "scene": "car_ramp_climb",
      "case_id": "car_ramp_climb_baseline",
      "video": "scenes/car_ramp_climb/cases/car_ramp_climb_baseline/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "玩具车冲上斜坡,越过坡顶,在空中翻转一圈后正面朝上落在坡后。",
          "en": "The toy car is pushed up a ramp, clears the top, turns over in the air and lands upright just past it."
        },
        "quantitative": {
          "zh": "玩具车以 2.7 m/s 冲上 20 度的光滑沥青坡,越过坡顶,在空中转完一圈后正面朝上落在坡后,行程 1.05 m,停在 x=-0.73。",
          "en": "The toy car is pushed at 2.7 m/s up the 20 deg slick-asphalt ramp, clears the top, completes its rotation in the air, and lands upright just past the ramp, ending at x=-0.73 after 1.05 m of travel."
        }
      },
      "editable_objects": [
        {
          "object_id": "car",
          "zh": "玩具车",
          "en": "the toy car",
          "properties": [
            "friction",
            "initial_velocity"
          ],
          "can_delete": false
        }
      ]
    },
    {
      "global_id": "curling_collision/curling_collision_baseline",
      "scene": "curling_collision",
      "case_id": "curling_collision_baseline",
      "video": "scenes/curling_collision/cases/curling_collision_baseline/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "红色冰壶和黄色冰壶从冰道两端相向掷出。两只冰壶各自滑行后停在中线两侧,靠得很近却没真正碰上。",
          "en": "The red stone and the yellow stone are launched at each other from opposite ends of the sheet. The two stones slide in and come to rest either side of the centre line, close but without quite touching."
        },
        "quantitative": {
          "zh": "红色冰壶和黄色冰壶都是 20 kg,从相距 5 m 处以 1.5 m/s 相向掷出。两只冰壶各自滑行 2.08 m,在第 40 帧前后相距不到 9 mm 却没真正碰上,最后停在中线两侧的 x=-0.42 和 x=+0.42。",
          "en": "The red stone and the yellow stone, both 20 kg, are launched at each other at 1.5 m/s from 5 m apart. The two stones each slide 2.08 m and close to within 9 mm around frame 40 without quite touching, settling at x=-0.42 and x=+0.42 either side of the centre line."
        }
      },
      "editable_objects": [
        {
          "object_id": "red_stone",
          "zh": "红色冰壶",
          "en": "the red stone",
          "properties": [
            "initial_velocity",
            "mass"
          ],
          "can_delete": false
        },
        {
          "object_id": "yellow_stone",
          "zh": "黄色冰壶",
          "en": "the yellow stone",
          "properties": [
            "initial_velocity",
            "mass"
          ],
          "can_delete": false
        },
        {
          "object_id": "stones",
          "zh": "两只冰壶",
          "en": "the two stones",
          "properties": [
            "initial_velocity",
            "restitution"
          ],
          "can_delete": false
        }
      ]
    },
    {
      "global_id": "dining_chain/dining_chain_baseline",
      "scene": "dining_chain",
      "case_id": "dining_chain_baseline",
      "video": "scenes/dining_chain/cases/dining_chain_baseline/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "可乐罐沿桌面被推出,撞上汽水杯,汽水杯又撞上牛奶盒。三者依次滑行后停下。",
          "en": "The cola can is pushed along the table into the soda cup, which is shoved on into the milk carton. All three slide before coming to rest."
        },
        "quantitative": {
          "zh": "可乐罐以 3.3 m/s 被推出,撞上 0.50 m 外的汽水杯,汽水杯又撞上再往前 0.50 m 的牛奶盒。三者依次滑行后停下 —— 可乐罐 1.31 m、汽水杯 0.91 m、牛奶盒 0.48 m。",
          "en": "The cola can is pushed at 3.3 m/s and strikes the soda cup 0.50 m downstream, which in turn strikes the milk carton another 0.50 m on. All three slide before coming to rest -- can 1.31 m, cup 0.91 m, carton 0.48 m."
        }
      },
      "editable_objects": [
        {
          "object_id": "can",
          "zh": "可乐罐",
          "en": "the cola can",
          "properties": [
            "friction",
            "initial_velocity",
            "mass",
            "restitution"
          ],
          "can_delete": true
        },
        {
          "object_id": "cup",
          "zh": "汽水杯",
          "en": "the soda cup",
          "properties": [
            "friction",
            "mass",
            "restitution"
          ],
          "can_delete": true
        },
        {
          "object_id": "milk",
          "zh": "牛奶盒",
          "en": "the milk carton",
          "properties": [
            "friction",
            "mass",
            "restitution"
          ],
          "can_delete": true
        }
      ]
    },
    {
      "global_id": "domino_chain/domino_chain_baseline",
      "scene": "domino_chain",
      "case_id": "domino_chain_baseline",
      "video": "scenes/domino_chain/cases/domino_chain_baseline/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "第 1 张骨牌起始就已倾过平衡点,倒下去撞倒第 2 张骨牌,第 2 张骨牌撞倒第 3 张骨牌,第 3 张骨牌再撞倒第 4 张骨牌。四张最后都平躺在桌面上。",
          "en": "The first domino starts already tipped past its balance point and falls into the second domino, which topples the third domino, which topples the fourth domino. All four end up flat on the table."
        },
        "quantitative": {
          "zh": "四张相同的骨牌间隔 0.80 m 立成一排。第 1 张骨牌预先倾斜到临界角以外,靠重力起倒,推倒第 2 张骨牌,第 2 张推倒第 3 张骨牌,第 3 张再推倒第 4 张骨牌。四张最后都平躺在桌面上。",
          "en": "Four identical tiles stand 0.80 m apart in a straight row. The first domino starts pre-tilted past its critical angle so gravity begins the fall; it topples the second domino, which topples the third domino, which topples the fourth domino. All four end up flat on the tabletop."
        }
      },
      "editable_objects": [
        {
          "object_id": "domino_1",
          "zh": "第 1 张骨牌",
          "en": "the first domino",
          "properties": [
            "friction",
            "mass",
            "restitution"
          ],
          "can_delete": true
        },
        {
          "object_id": "domino_2",
          "zh": "第 2 张骨牌",
          "en": "the second domino",
          "properties": [
            "friction",
            "mass",
            "restitution"
          ],
          "can_delete": true
        },
        {
          "object_id": "domino_3",
          "zh": "第 3 张骨牌",
          "en": "the third domino",
          "properties": [
            "friction",
            "mass",
            "restitution"
          ],
          "can_delete": true
        },
        {
          "object_id": "domino_4",
          "zh": "第 4 张骨牌",
          "en": "the fourth domino",
          "properties": [
            "friction",
            "mass",
            "restitution"
          ],
          "can_delete": true
        }
      ]
    },
    {
      "global_id": "mahjong_dice/mahjong_dice_baseline",
      "scene": "mahjong_dice",
      "case_id": "mahjong_dice_baseline",
      "video": "scenes/mahjong_dice/cases/mahjong_dice_baseline/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "红色骰子和白色骰子垂直落进麻将桌中央的骰盅。两颗都没有旋转和横向推力,各弹几下后停稳。",
          "en": "The red die and the white die are dropped straight down into the mahjong table's centre tray. Neither is spun or pushed sideways; each bounces a few times and settles."
        },
        "quantitative": {
          "zh": "红色骰子和白色骰子垂直落进麻将桌中央的骰盅 —— 红色骰子下落 0.60 m、初速 1.5 m/s,白色骰子下落 0.65 m、初速 0.8 m/s。没有旋转也没有横向推力,各弹几下后都在片尾前很早就停稳。",
          "en": "The red die and the white die are dropped straight down into the mahjong table's centre tray -- the red die through 0.60 m at 1.5 m/s, the white die through 0.65 m at 0.8 m/s. No spin and no lateral push; each bounces a few times and both settle well before the clip ends."
        }
      },
      "editable_objects": [
        {
          "object_id": "red_die",
          "zh": "红色骰子",
          "en": "the red die",
          "properties": [
            "friction",
            "initial_velocity",
            "mass",
            "restitution"
          ],
          "can_delete": true
        },
        {
          "object_id": "white_die",
          "zh": "白色骰子",
          "en": "the white die",
          "properties": [
            "friction",
            "initial_velocity",
            "mass",
            "restitution"
          ],
          "can_delete": true
        }
      ]
    },
    {
      "global_id": "picnic_apple_ball/picnic_apple_ball_baseline",
      "scene": "picnic_apple_ball",
      "case_id": "picnic_apple_ball_baseline",
      "video": "scenes/picnic_apple_ball/cases/picnic_apple_ball_baseline/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "苹果从头顶的树枝落到草地上的足球上,落点偏离球心,把足球拧得滚起来,滚一段后被摩擦停住;苹果自己则弹开。",
          "en": "The apple falls from an overhead branch onto the soccer ball resting on the grass. It lands off-centre, torquing the ball into a roll until friction stops it, and bounces away itself."
        },
        "quantitative": {
          "zh": "苹果从头顶的树枝落到草地上的足球上,落点偏离球心 0.105 m。这个力臂足以把球拧得滚起来:足球在草地上滚 0.54 m 后被摩擦停住,苹果则弹开,相对落点移动 2.37 m。",
          "en": "The apple falls from an overhead branch onto the soccer ball resting on the grass, landing 0.105 m off the ball's centre. That lever arm is enough to torque the ball into a roll: the soccer ball travels 0.54 m across the grass before friction stops it, while the apple bounces on to end 2.37 m from where it fell."
        }
      },
      "editable_objects": [
        {
          "object_id": "apple",
          "zh": "苹果",
          "en": "the apple",
          "properties": [
            "friction",
            "mass",
            "restitution"
          ],
          "can_delete": true
        },
        {
          "object_id": "soccer_ball",
          "zh": "足球",
          "en": "the soccer ball",
          "properties": [
            "friction",
            "mass",
            "restitution"
          ],
          "can_delete": true
        }
      ]
    },
    {
      "global_id": "pool_collision/pool_collision_baseline",
      "scene": "pool_collision",
      "case_id": "pool_collision_baseline",
      "video": "scenes/pool_collision/cases/pool_collision_baseline/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "母球沿台面被推向目标球并正面撞上。母球接触瞬间停死,目标球向前滚一段后被摩擦停住。",
          "en": "The cue ball is pushed along the felt at the target ball and hits it head-on. The cue ball stops dead on contact and the target ball rolls forward before friction brings it to rest."
        },
        "quantitative": {
          "zh": "母球以 1.0 m/s 被推出,滚过 0.57 m 后在第 15 帧正撞上目标球。母球接触瞬间停死,目标球向前滚 0.12 m 后被摩擦停住。",
          "en": "The cue ball is pushed at 1.0 m/s and hits the target ball head-on on frame 15 after 0.57 m of travel. The cue ball stops dead on contact and the target ball rolls forward 0.12 m before friction brings it to rest."
        }
      },
      "editable_objects": [
        {
          "object_id": "cue_ball",
          "zh": "母球",
          "en": "the cue ball",
          "properties": [
            "friction",
            "initial_velocity",
            "mass",
            "restitution"
          ],
          "can_delete": true
        },
        {
          "object_id": "target_ball",
          "zh": "目标球",
          "en": "the target ball",
          "properties": [
            "friction",
            "mass",
            "restitution"
          ],
          "can_delete": true
        }
      ]
    },
    {
      "global_id": "ramp_collision/ramp_baseline",
      "scene": "ramp_collision",
      "case_id": "ramp_baseline",
      "video": "scenes/ramp_collision/cases/ramp_baseline/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "红球从斜坡滚下到桌面,冲向停在那里的蓝球和黄球。它只够到蓝球、把它轻轻撞开;黄球始终没被碰到。",
          "en": "The red ball rolls down a ramp onto the table towards the blue marble and the yellow marble waiting there. It reaches only the blue marble and nudges it a little; the yellow marble is never touched."
        },
        "quantitative": {
          "zh": "红球从 12 度斜坡滚下到桌面,冲向蓝球和黄球。它只够到其中一颗:蓝球被撞开 0.07 m,黄球始终没被碰到。红球相对起点移动 0.26 m 后停下。",
          "en": "The red ball rolls down a 12 deg ramp onto the table towards the blue marble and the yellow marble. It reaches only one of them: the blue marble is nudged 0.07 m and the yellow marble is never touched. The red ball stops 0.26 m from where it set off."
        }
      },
      "editable_objects": [
        {
          "object_id": "red_ball",
          "zh": "红球",
          "en": "the red ball",
          "properties": [
            "friction",
            "mass",
            "restitution"
          ],
          "can_delete": false
        },
        {
          "object_id": "blue_marble",
          "zh": "蓝球",
          "en": "the blue marble",
          "properties": [
            "mass"
          ],
          "can_delete": true
        },
        {
          "object_id": "yellow_marble",
          "zh": "黄球",
          "en": "the yellow marble",
          "properties": [
            "mass"
          ],
          "can_delete": true
        }
      ]
    },
    {
      "global_id": "table_drop_collision/table_drop_collision_baseline",
      "scene": "table_drop_collision",
      "case_id": "table_drop_collision_baseline",
      "video": "scenes/table_drop_collision/cases/table_drop_collision_baseline/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "新网球被推过桌面,滚出桌沿掉到地毯上,砸在等在那里的旧网球上并把它推走一段。",
          "en": "The new tennis ball is pushed along the table, runs off the lip and drops to the rug, landing on the old tennis ball waiting there and driving it along the floor."
        },
        "quantitative": {
          "zh": "新网球以 1.28 m/s 被推过桌面,滚出桌沿掉到地毯上,砸在等在那里的旧网球上。旧网球被推出 0.30 m;新网球相对起点移动 0.88 m。",
          "en": "The new tennis ball is pushed at 1.28 m/s along the table, runs off the lip, drops to the rug and lands on the old tennis ball waiting there. The old tennis ball is driven 0.30 m along the floor; the new one ends 0.88 m from where it started."
        }
      },
      "editable_objects": [
        {
          "object_id": "rolling_ball",
          "zh": "新网球",
          "en": "the new tennis ball",
          "properties": [
            "friction",
            "initial_velocity",
            "mass",
            "restitution"
          ],
          "can_delete": false
        },
        {
          "object_id": "target_ball",
          "zh": "旧网球",
          "en": "the old tennis ball",
          "properties": [
            "friction",
            "mass",
            "restitution"
          ],
          "can_delete": true
        }
      ]
    },
    {
      "global_id": "table_marble_collision/table_marble_collision_baseline",
      "scene": "table_marble_collision",
      "case_id": "table_marble_collision_baseline",
      "video": "scenes/table_marble_collision/cases/table_marble_collision_baseline/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "大玻璃球沿吧台滚向停在远端的小玻璃球。小玻璃球被撞得向前跑,大玻璃球在后面继续前进。",
          "en": "The big marble is rolled along the bar table into the small marble sitting near the far end. The small marble is sent forward and the big marble carries on behind it."
        },
        "quantitative": {
          "zh": "100 mm 的大玻璃球以 1.31 m/s 沿吧台滚向停在远端的 50 mm 小玻璃球。两球是同一种玻璃,小玻璃球质量只有八分之一:撞击把它送出 0.68 m,大玻璃球则继续前进,全程 0.89 m。",
          "en": "The big marble, 100 mm across, is rolled at 1.31 m/s along the bar table into the small marble, 50 mm across, sitting near the far end. Both are the same glass, so the small marble is an eighth of the mass: the impact sends it 0.68 m forward while the big marble carries on for 0.89 m in all."
        }
      },
      "editable_objects": [
        {
          "object_id": "big_marble",
          "zh": "大玻璃球",
          "en": "the big marble",
          "properties": [
            "friction",
            "initial_velocity",
            "mass",
            "restitution"
          ],
          "can_delete": false
        },
        {
          "object_id": "small_marble",
          "zh": "小玻璃球",
          "en": "the small marble",
          "properties": [
            "friction",
            "mass",
            "restitution"
          ],
          "can_delete": true
        }
      ]
    },
    {
      "global_id": "tennis_flight/tennis_flight_baseline",
      "scene": "tennis_flight",
      "case_id": "tennis_flight_baseline",
      "video": "scenes/tennis_flight/cases/tennis_flight_baseline/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "网球被击出后在空中划出弧线,越过球网,在另一侧落地并滚出一段后停下。",
          "en": "The tennis ball is hit into the air, arcs over the net, touches down on the far side and rolls out to a stop."
        },
        "quantitative": {
          "zh": "网球从 (-4, 0, 1.5) 以 (4.5, 0, 4.5) m/s 发出,越过 x=0 处的球网,第 29 帧首次落地,在 4 秒窗口结束时滚到 x=+3.31。",
          "en": "The tennis ball is launched from (-4, 0, 1.5) at (4.5, 0, 4.5) m/s. It arcs over the net at x=0, first touches down on frame 29, and rolls out to x=+3.31 by the end of the 4 s window."
        }
      },
      "editable_objects": [
        {
          "object_id": "ball",
          "zh": "网球",
          "en": "the tennis ball",
          "properties": [
            "friction",
            "initial_velocity",
            "mass",
            "restitution"
          ],
          "can_delete": false
        }
      ]
    },
    {
      "global_id": "toy_car_ball/toy_car_ball_baseline",
      "scene": "toy_car_ball",
      "case_id": "toy_car_ball_baseline",
      "video": "scenes/toy_car_ball/cases/toy_car_ball_baseline/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "玩具小车沿架子被推出,追尾停在远端边缘的玩具球。玩具球被撞下架子落到地面;小车留在架子上。",
          "en": "The toy car is pushed along a shelf and rear-ends the toy ball sitting near the far edge. The toy ball is knocked over the edge and lands on the floor; the car stays on the shelf."
        },
        "quantitative": {
          "zh": "0.35 kg 的玩具小车以 0.6 m/s 沿架子推出,追尾停在远端边缘的 0.05 kg 玩具球。玩具球被撞下架子,落到地面 x=-0.90 处,相对原位移动 0.89 m。玩具小车留在架子上,前进 0.40 m 后停下。",
          "en": "The toy car, 0.35 kg, is pushed at 0.6 m/s along a shelf and rear-ends the toy ball, 0.05 kg, sitting near the far edge. The toy ball is knocked over the edge and lands on the floor at x=-0.90, 0.89 m from where it sat. The toy car stays on the shelf, stopping 0.40 m along."
        }
      },
      "editable_objects": [
        {
          "object_id": "toy_car",
          "zh": "玩具小车",
          "en": "the toy car",
          "properties": [
            "friction",
            "initial_velocity",
            "mass",
            "restitution"
          ],
          "can_delete": false
        },
        {
          "object_id": "toy_ball",
          "zh": "玩具球",
          "en": "the toy ball",
          "properties": [
            "friction",
            "mass",
            "restitution"
          ],
          "can_delete": true
        }
      ]
    },
    {
      "global_id": "twin_ramp_collision/twin_ramp_collision_baseline",
      "scene": "twin_ramp_collision",
      "case_id": "twin_ramp_collision_baseline",
      "video": "scenes/twin_ramp_collision/cases/twin_ramp_collision_baseline/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "紫色玻璃球和黄色玻璃球从对称斜坡的顶端同时释放,滚下后在坡底正面相撞。两球各自被弹回自己那侧的坡上一小段,再滚下来,最后停在谷底。",
          "en": "The purple marble and the yellow marble are released together from the crests of matched ramps, roll down and meet head-on at the bottom. Both run a short way back up their own ramp, roll down again and settle in the valley."
        },
        "quantitative": {
          "zh": "紫色玻璃球和黄色玻璃球都是 64 mm,从对称斜坡的顶端同时释放,靠重力滚下,第 35 帧在坡底正面相撞,各自约 0.92 m/s。两球都被弹回自己那侧的坡上一小段,再滚下来,最后停在谷底的 x=+0.07 和 x=-0.07。",
          "en": "The purple marble and the yellow marble, both 64 mm, are released together from the crests of matched ramps, roll down under gravity, and meet head-on at the bottom on frame 35, each doing about 0.92 m/s. Both run a short way back up their own ramp, roll down again, and settle in the valley at x=+0.07 and x=-0.07."
        }
      },
      "editable_objects": [
        {
          "object_id": "purple_ball",
          "zh": "紫色玻璃球",
          "en": "the purple marble",
          "properties": [
            "friction",
            "mass",
            "restitution"
          ],
          "can_delete": true
        },
        {
          "object_id": "yellow_ball",
          "zh": "黄色玻璃球",
          "en": "the yellow marble",
          "properties": [
            "friction",
            "mass",
            "restitution"
          ],
          "can_delete": true
        }
      ]
    }
  ],
  "edits": [
    {
      "global_id": "air_hockey_chain/edit_heavy_middle_mallet",
      "scene": "air_hockey_chain",
      "case_id": "edit_heavy_middle_mallet",
      "source_case_id": "air_hockey_chain_baseline",
      "source_video": "scenes/air_hockey_chain/cases/air_hockey_chain_baseline/video.mp4",
      "edited_video": "scenes/air_hockey_chain/cases/edit_heavy_middle_mallet/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把红色球槌的质量调大一些。",
          "en": "From the start of the clip, increase the red mallet's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把红色球槌的质量增加到原来的 4 倍。",
          "en": "From frame 1 onwards, increase the red mallet's mass to 4 times its original value."
        }
      },
      "edit_dsl": "SET red_mallet.mass TIMES 4",
      "edit_kind": "SET",
      "object_id": "red_mallet",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (red_mallet)": {
          "from": 0.12,
          "to": 0.48
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Middle mallet made 4x heavier. Momentum is no longer cancelled at the first impact: blue rebounds backwards up the table instead of stopping dead on red, ending further from the camera than it started. Red leaves with 0.30 m/s instead of 0.75, and the chain still reaches white but carries only 31% of the push instead of 88%.",
      "ground_truth": "scenes/air_hockey_chain/cases/edit_heavy_middle_mallet/ground_truth_transforms.json",
      "thumbnail": "thumbnails/air_hockey_chain/edit_heavy_middle_mallet.jpg"
    },
    {
      "global_id": "air_hockey_chain/edit_heavy_last_mallet",
      "scene": "air_hockey_chain",
      "case_id": "edit_heavy_last_mallet",
      "source_case_id": "air_hockey_chain_baseline",
      "source_video": "scenes/air_hockey_chain/cases/air_hockey_chain_baseline/video.mp4",
      "edited_video": "scenes/air_hockey_chain/cases/edit_heavy_last_mallet/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把白色球槌的质量调大一些。",
          "en": "From the start of the clip, increase the white mallet's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把白色球槌的质量增加到原来的 10 倍。",
          "en": "From frame 1 onwards, increase the white mallet's mass to 10 times its original value."
        }
      },
      "edit_dsl": "SET white_mallet.mass TIMES 10",
      "edit_kind": "SET",
      "object_id": "white_mallet",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (white_mallet)": {
          "from": 0.12,
          "to": 1.2
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Last mallet made 10x heavier. The first handoff is untouched -- blue still stops dead on red -- but the second one fails: red bounces back up the table off white instead of stopping, and white only creeps forward at 0.13 m/s rather than carrying the push into the near rail.",
      "ground_truth": "scenes/air_hockey_chain/cases/edit_heavy_last_mallet/ground_truth_transforms.json",
      "thumbnail": "thumbnails/air_hockey_chain/edit_heavy_last_mallet.jpg"
    },
    {
      "global_id": "air_hockey_chain/edit_heavy_striker",
      "scene": "air_hockey_chain",
      "case_id": "edit_heavy_striker",
      "source_case_id": "air_hockey_chain_baseline",
      "source_video": "scenes/air_hockey_chain/cases/air_hockey_chain_baseline/video.mp4",
      "edited_video": "scenes/air_hockey_chain/cases/edit_heavy_striker/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把蓝色球槌的质量调大一些。",
          "en": "From the start of the clip, increase the blue mallet's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把蓝色球槌的质量增加到原来的 10 倍。",
          "en": "From frame 1 onwards, increase the blue mallet's mass to 10 times its original value."
        }
      },
      "edit_dsl": "SET blue_mallet.mass TIMES 10",
      "edit_kind": "SET",
      "object_id": "blue_mallet",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (blue_mallet)": {
          "from": 0.12,
          "to": 1.2
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "The pushed mallet made 10x heavier. Blue keeps 80% of its speed through the impact and drives on behind red rather than stopping, and red leaves faster than blue arrived (1.37 m/s against a 0.8 m/s push). The whole chain accelerates and all three finish bunched together against the near rail instead of strung out along the table where each handoff happened.",
      "ground_truth": "scenes/air_hockey_chain/cases/edit_heavy_striker/ground_truth_transforms.json",
      "thumbnail": "thumbnails/air_hockey_chain/edit_heavy_striker.jpg"
    },
    {
      "global_id": "air_hockey_chain/edit_dead_striker_face",
      "scene": "air_hockey_chain",
      "case_id": "edit_dead_striker_face",
      "source_case_id": "air_hockey_chain_baseline",
      "source_video": "scenes/air_hockey_chain/cases/air_hockey_chain_baseline/video.mp4",
      "edited_video": "scenes/air_hockey_chain/cases/edit_dead_striker_face/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把蓝色球槌的恢复系数调小一些。",
          "en": "From the start of the clip, decrease the blue mallet's restitution."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把蓝色球槌的恢复系数减少到原来的 0.3 倍。",
          "en": "From frame 1 onwards, reduce the blue mallet's restitution to 0.3 times its original value."
        }
      },
      "edit_dsl": "SET blue_mallet.restitution TIMES 0.3",
      "edit_kind": "SET",
      "object_id": "blue_mallet",
      "property": "restitution",
      "outcome_type": "restitution_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "restitution (blue_mallet)": {
          "from": 0.95,
          "to": 0.285
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Soft face on the pushed mallet only, so the first impact is a shove rather than a clean handoff. Blue no longer stops on contact: it slides on behind red for 1.16 m against the baseline's 0.48 m and is still drifting at 0.09 m/s when the clip ends. Red leaves the collision at 0.51 m/s instead of 0.75, and what reaches white is down to 0.35 m/s -- half the baseline's 0.70.",
      "ground_truth": "scenes/air_hockey_chain/cases/edit_dead_striker_face/ground_truth_transforms.json",
      "thumbnail": "thumbnails/air_hockey_chain/edit_dead_striker_face.jpg"
    },
    {
      "global_id": "air_hockey_chain/edit_grippy_striker",
      "scene": "air_hockey_chain",
      "case_id": "edit_grippy_striker",
      "source_case_id": "air_hockey_chain_baseline",
      "source_video": "scenes/air_hockey_chain/cases/air_hockey_chain_baseline/video.mp4",
      "edited_video": "scenes/air_hockey_chain/cases/edit_grippy_striker/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把蓝色球槌的摩擦系数调大一些。",
          "en": "From the start of the clip, increase the blue mallet's friction coefficient."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把蓝色球槌的摩擦系数增加到原来的 25 倍。",
          "en": "From frame 1 onwards, increase the blue mallet's friction coefficient to 25 times its original value."
        }
      },
      "edit_dsl": "SET blue_mallet.friction TIMES 25",
      "edit_kind": "SET",
      "object_id": "blue_mallet",
      "property": "friction",
      "outcome_type": "friction_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "friction (blue_mallet)": {
          "from": 0.06,
          "to": 1.5
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "The pushed mallet's base made to grip instead of glide -- as if it alone had lost its air cushion. PyBullet multiplies the pair, so the effective coefficient against the table goes from 0.0036 to 0.09. Blue decelerates and stops after 36 cm, well short of red. No collision happens at all: the disc riding on almost nothing is what makes the relay possible in the first place, not a detail of it. Red and white never move, and both still glide freely.",
      "ground_truth": "scenes/air_hockey_chain/cases/edit_grippy_striker/ground_truth_transforms.json",
      "thumbnail": "thumbnails/air_hockey_chain/edit_grippy_striker.jpg"
    },
    {
      "global_id": "air_hockey_chain/edit_soft_push",
      "scene": "air_hockey_chain",
      "case_id": "edit_soft_push",
      "source_case_id": "air_hockey_chain_baseline",
      "source_video": "scenes/air_hockey_chain/cases/air_hockey_chain_baseline/video.mp4",
      "edited_video": "scenes/air_hockey_chain/cases/edit_soft_push/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把蓝色球槌的初速度大小调小一些。",
          "en": "From the start of the clip, decrease the blue mallet's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把蓝色球槌的初速度大小减少到原来的 0.4 倍。",
          "en": "From frame 1 onwards, reduce the blue mallet's initial speed to 0.4 times its original value."
        }
      },
      "edit_dsl": "SET blue_mallet.initial_velocity TIMES 0.4",
      "edit_kind": "SET",
      "object_id": "blue_mallet",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (blue_mallet)": {
          "from": 0.8,
          "to": 0.32
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Everything correct but the push is too gentle. Blue still coasts the length of the gap and still stops dead on red -- the collision physics is untouched -- but red leaves at only 0.23 m/s, is still crawling at 0.15 m/s after 0.44 m, and never covers the 0.60 m to white. The white mallet does not move at all, so the chain dies one link early.",
      "ground_truth": "scenes/air_hockey_chain/cases/edit_soft_push/ground_truth_transforms.json",
      "thumbnail": "thumbnails/air_hockey_chain/edit_soft_push.jpg"
    },
    {
      "global_id": "air_hockey_chain/edit_remove_middle_mallet_mid_slide",
      "scene": "air_hockey_chain",
      "case_id": "edit_remove_middle_mallet_mid_slide",
      "source_case_id": "air_hockey_chain_baseline",
      "source_video": "scenes/air_hockey_chain/cases/air_hockey_chain_baseline/video.mp4",
      "edited_video": "scenes/air_hockey_chain/cases/edit_remove_middle_mallet_mid_slide/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "在视频前段,把红色球槌从场景中删除。",
          "en": "Early in the clip, remove the red mallet from the scene."
        },
        "quantitative": {
          "zh": "从第 22 帧开始,把红色球槌从场景中删除。",
          "en": "From frame 22 onwards, remove the red mallet from the scene."
        }
      },
      "edit_dsl": "DELETE red_mallet AT FRAME 22",
      "edit_kind": "DELETE",
      "object_id": "red_mallet",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 22,
      "timing": "partway",
      "physics_diff": {
        "red_mallet": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 22,
          "total_frames": 96,
          "unedited_frames": [
            1,
            21
          ]
        }
      },
      "edit_summary": "Middle mallet removed at frame 22, six frames after blue hands off to it and nine before it would have reached white. Frames 1-21 are the source video frame for frame, first impact included: blue is left standing at x=1.31 having given nearly all of its speed away, red slides on and then is gone at x=1.02, and white is never touched -- it is still at its start, x=0.598, on the last frame. One handoff instead of two. The whole-clip version of the same delete (edit_remove_middle_mallet) is a different video again: with no red mallet to hit, blue never stops, coasts the length of the table and strikes white itself at frame 35.",
      "ground_truth": "scenes/air_hockey_chain/cases/edit_remove_middle_mallet_mid_slide/ground_truth_transforms.json",
      "thumbnail": "thumbnails/air_hockey_chain/edit_remove_middle_mallet_mid_slide.jpg"
    },
    {
      "global_id": "air_hockey_chain/edit_remove_middle_mallet",
      "scene": "air_hockey_chain",
      "case_id": "edit_remove_middle_mallet",
      "source_case_id": "air_hockey_chain_baseline",
      "source_video": "scenes/air_hockey_chain/cases/air_hockey_chain_baseline/video.mp4",
      "edited_video": "scenes/air_hockey_chain/cases/edit_remove_middle_mallet/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把红色球槌从场景中删除。",
          "en": "From the start of the clip, remove the red mallet from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把红色球槌从场景中删除。",
          "en": "From frame 1 onwards, remove the red mallet from the scene."
        }
      },
      "edit_dsl": "DELETE red_mallet",
      "edit_kind": "DELETE",
      "object_id": "red_mallet",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "red_mallet": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Middle mallet removed. Blue coasts through the empty middle of the table and strikes white directly, losing so little to the surface on the way that the single handoff is cleaner than either of the baseline's two: white leaves with 90% of the original push. One impact instead of two, and it happens later and nearer the camera.",
      "ground_truth": "scenes/air_hockey_chain/cases/edit_remove_middle_mallet/ground_truth_transforms.json",
      "thumbnail": "thumbnails/air_hockey_chain/edit_remove_middle_mallet.jpg"
    },
    {
      "global_id": "air_hockey_chain/edit_remove_last_mallet",
      "scene": "air_hockey_chain",
      "case_id": "edit_remove_last_mallet",
      "source_case_id": "air_hockey_chain_baseline",
      "source_video": "scenes/air_hockey_chain/cases/air_hockey_chain_baseline/video.mp4",
      "edited_video": "scenes/air_hockey_chain/cases/edit_remove_last_mallet/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把白色球槌从场景中删除。",
          "en": "From the start of the clip, remove the white mallet from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把白色球槌从场景中删除。",
          "en": "From frame 1 onwards, remove the white mallet from the scene."
        }
      },
      "edit_dsl": "DELETE white_mallet",
      "edit_kind": "DELETE",
      "object_id": "white_mallet",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "white_mallet": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Last mallet removed. The first handoff is identical to the baseline -- blue stops dead, red leaves at 0.75 m/s -- but red then runs the rest of the table unobstructed and into the near rail instead of handing over at the three-quarter point.",
      "ground_truth": "scenes/air_hockey_chain/cases/edit_remove_last_mallet/ground_truth_transforms.json",
      "thumbnail": "thumbnails/air_hockey_chain/edit_remove_last_mallet.jpg"
    },
    {
      "global_id": "air_hockey_chain/edit_add_mallet_last_gap",
      "scene": "air_hockey_chain",
      "case_id": "edit_add_mallet_last_gap",
      "source_case_id": "air_hockey_chain_baseline",
      "source_video": "scenes/air_hockey_chain/cases/air_hockey_chain_baseline/video.mp4",
      "edited_video": "scenes/air_hockey_chain/cases/edit_add_mallet_last_gap/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,在红色球槌和白色球槌的连线上、大致中间的位置,放一个绿色球槌。",
          "en": "From the start of the clip, place the green mallet on the line between the red mallet and the white mallet, about midway between them."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,在红色球槌和白色球槌连线的中点放一个绿色球槌。",
          "en": "From frame 1 onwards, place the green mallet at the midpoint of the line between the red mallet and the white mallet."
        }
      },
      "edit_dsl": "ADD green_mallet BETWEEN red_mallet AND white_mallet AT MIDPOINT",
      "edit_kind": "ADD",
      "object_id": "green_mallet",
      "property": null,
      "outcome_type": "object_added",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "green_mallet": {
          "from": "absent",
          "to": "present",
          "position": {
            "on_line_between": [
              "red_mallet",
              "white_mallet"
            ],
            "at": "midpoint",
            "measured_from": null,
            "fraction_from_endpoint_a": 0.5,
            "resolved_location": [
              0.896625,
              0.0,
              0.0328
            ],
            "endpoint_locations": [
              [
                1.1955,
                0.0,
                0.0328
              ],
              [
                0.59775,
                0.0,
                0.0328
              ]
            ]
          }
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "A fourth mallet set down at the midpoint of the red-to-white line. The relay gains a stage: blue still hands off after its usual 0.48 m, but red now runs only 0.18 m before it meets green instead of 0.49 m to reach white. Green carries the push the remaining 0.43 m, and white finishes with 0.52 m of travel against the baseline's 0.49 m. Each striker still stops close to where it hits, so the extra handoff reads as a pause in the middle of the table rather than as a loss of reach.",
      "ground_truth": "scenes/air_hockey_chain/cases/edit_add_mallet_last_gap/ground_truth_transforms.json",
      "thumbnail": "thumbnails/air_hockey_chain/edit_add_mallet_last_gap.jpg"
    },
    {
      "global_id": "ball_block/edit_heavy_block",
      "scene": "ball_block",
      "case_id": "edit_heavy_block",
      "source_case_id": "ball_block_baseline",
      "source_video": "scenes/ball_block/cases/ball_block_baseline/video.mp4",
      "edited_video": "scenes/ball_block/cases/edit_heavy_block/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把木块的质量调大一些。",
          "en": "From the start of the clip, increase the wooden block's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把木块的质量增加到原来的 10 倍。",
          "en": "From frame 1 onwards, increase the wooden block's mass to 10 times its original value."
        }
      },
      "edit_dsl": "SET wood_block.mass TIMES 10",
      "edit_kind": "SET",
      "object_id": "wood_block",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (wood_block)": {
          "from": 0.65,
          "to": 6.5
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Block made 10x heavier. It barely moves -- 6 cm instead of 1.47 m -- and the ball rebounds off it back the way it came instead of following it across the floor. The contact happens at the same moment and the same place as in the source.",
      "ground_truth": "scenes/ball_block/cases/edit_heavy_block/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ball_block/edit_heavy_block.jpg"
    },
    {
      "global_id": "ball_block/edit_heavy_ball",
      "scene": "ball_block",
      "case_id": "edit_heavy_ball",
      "source_case_id": "ball_block_baseline",
      "source_video": "scenes/ball_block/cases/ball_block_baseline/video.mp4",
      "edited_video": "scenes/ball_block/cases/edit_heavy_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把红球的质量调大一些。",
          "en": "From the start of the clip, increase the ball's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把红球的质量增加到原来的 10 倍。",
          "en": "From frame 1 onwards, increase the ball's mass to 10 times its original value."
        }
      },
      "edit_dsl": "SET ball.mass TIMES 10",
      "edit_kind": "SET",
      "object_id": "ball",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (ball)": {
          "from": 0.58,
          "to": 5.8
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Ball made 10x heavier. It plows through the impact barely slowed (3.35 m/s out of 4.38 m/s in, against 0.65 m/s in the source) and launches the block at 5.37 m/s, driving it 4.73 m instead of 1.47 m -- the block leaves frame rather than sliding to a stop. Both it and the ball are still travelling when the clip ends.",
      "ground_truth": "scenes/ball_block/cases/edit_heavy_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ball_block/edit_heavy_ball.jpg"
    },
    {
      "global_id": "ball_block/edit_slow_ball",
      "scene": "ball_block",
      "case_id": "edit_slow_ball",
      "source_case_id": "ball_block_baseline",
      "source_video": "scenes/ball_block/cases/ball_block_baseline/video.mp4",
      "edited_video": "scenes/ball_block/cases/edit_slow_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把红球的初速度大小调小一些。",
          "en": "From the start of the clip, decrease the ball's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把红球的初速度大小减少到原来的 0.7 倍。",
          "en": "From frame 1 onwards, reduce the ball's initial speed to 0.7 times its original value."
        }
      },
      "edit_dsl": "SET ball.initial_velocity TIMES 0.7",
      "edit_kind": "SET",
      "object_id": "ball",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (ball)": {
          "from": 6.0,
          "to": 4.2
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Ball launched at 4.2 m/s instead of 6. It reaches the block much later, on frame 33 against the baseline's 13, and the contact is a nudge rather than an impact: the block leaves at 1.09 m/s instead of 2.83 and shifts 0.31 m instead of 1.47 m.",
      "ground_truth": "scenes/ball_block/cases/edit_slow_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ball_block/edit_slow_ball.jpg"
    },
    {
      "global_id": "ball_block/edit_grippy_block",
      "scene": "ball_block",
      "case_id": "edit_grippy_block",
      "source_case_id": "ball_block_baseline",
      "source_video": "scenes/ball_block/cases/ball_block_baseline/video.mp4",
      "edited_video": "scenes/ball_block/cases/edit_grippy_block/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把木块的摩擦系数调大一些。",
          "en": "From the start of the clip, increase the wooden block's friction coefficient."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把木块的摩擦系数增加到原来的 5 倍。",
          "en": "From frame 1 onwards, increase the wooden block's friction coefficient to 5 times its original value."
        }
      },
      "edit_dsl": "SET wood_block.friction TIMES 5",
      "edit_kind": "SET",
      "object_id": "wood_block",
      "property": "friction",
      "outcome_type": "friction_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "friction (wood_block)": {
          "from": 0.32,
          "to": 1.6
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Block's friction against the floor raised, as if it had a rubber underside. It is struck just as hard -- it still leaves the collision at 2.45 m/s against the baseline's 2.83 -- but grinds to a halt after 0.29 m instead of coasting 1.47 m. The impact frame is unchanged at 13.",
      "ground_truth": "scenes/ball_block/cases/edit_grippy_block/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ball_block/edit_grippy_block.jpg"
    },
    {
      "global_id": "ball_block/edit_bouncy_block",
      "scene": "ball_block",
      "case_id": "edit_bouncy_block",
      "source_case_id": "ball_block_baseline",
      "source_video": "scenes/ball_block/cases/ball_block_baseline/video.mp4",
      "edited_video": "scenes/ball_block/cases/edit_bouncy_block/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把木块的恢复系数调大一些。",
          "en": "From the start of the clip, increase the wooden block's restitution."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把木块的恢复系数增加到原来的 1.8 倍。",
          "en": "From frame 1 onwards, increase the wooden block's restitution to 1.8 times its original value."
        }
      },
      "edit_dsl": "SET wood_block.restitution TIMES 1.8",
      "edit_kind": "SET",
      "object_id": "wood_block",
      "property": "restitution",
      "outcome_type": "restitution_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "restitution (wood_block)": {
          "from": 0.55,
          "to": 0.99
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Block's faces made near-perfectly elastic. More of the ball's momentum goes into the block and less stays with the ball: the block leaves the impact at 3.50 m/s against the baseline's 2.83 and is driven 2.10 m instead of 1.47 m, while the ball ends 2.55 m from its start instead of 4.17 m and is almost dead at 0.09 m/s. Contact is unchanged at frame 13; only what follows it changes.",
      "ground_truth": "scenes/ball_block/cases/edit_bouncy_block/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ball_block/edit_bouncy_block.jpg"
    },
    {
      "global_id": "ball_block/edit_remove_block",
      "scene": "ball_block",
      "case_id": "edit_remove_block",
      "source_case_id": "ball_block_baseline",
      "source_video": "scenes/ball_block/cases/ball_block_baseline/video.mp4",
      "edited_video": "scenes/ball_block/cases/edit_remove_block/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把木块从场景中删除。",
          "en": "From the start of the clip, remove the wooden block from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把木块从场景中删除。",
          "en": "From frame 1 onwards, remove the wooden block from the scene."
        }
      },
      "edit_dsl": "DELETE wood_block",
      "edit_kind": "DELETE",
      "object_id": "wood_block",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "wood_block": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Block removed. The ball rolls straight through the spot where it used to stand and on out of frame, with nothing in the video ever interrupting it. No collision at all.",
      "ground_truth": "scenes/ball_block/cases/edit_remove_block/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ball_block/edit_remove_block.jpg"
    },
    {
      "global_id": "ball_block/edit_remove_block_after_impact",
      "scene": "ball_block",
      "case_id": "edit_remove_block_after_impact",
      "source_case_id": "ball_block_baseline",
      "source_video": "scenes/ball_block/cases/ball_block_baseline/video.mp4",
      "edited_video": "scenes/ball_block/cases/edit_remove_block_after_impact/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "在视频前段,把木块从场景中删除。",
          "en": "Early in the clip, remove the wooden block from the scene."
        },
        "quantitative": {
          "zh": "从第 17 帧开始,把木块从场景中删除。",
          "en": "From frame 17 onwards, remove the wooden block from the scene."
        }
      },
      "edit_dsl": "DELETE wood_block AT FRAME 17",
      "edit_kind": "DELETE",
      "object_id": "wood_block",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 17,
      "timing": "partway",
      "physics_diff": {
        "wood_block": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 17,
          "total_frames": 96,
          "unedited_frames": [
            1,
            16
          ]
        }
      },
      "edit_summary": "Block removed at frame 17, four frames after the ball strikes it at frame 13. Frames 1-16 are the source video frame for frame, impact included: the ball arrives at 4.5 m/s and is left with 0.8, and the block is already 0.40 m along and moving at 2.8 m/s when it disappears. The ball then coasts on at its post-impact speed exactly as in the source. The whole-clip version of the same delete (edit_remove_block) is a different video again: with nothing to hit, the ball never slows and ends 7 m further down the floor.",
      "ground_truth": "scenes/ball_block/cases/edit_remove_block_after_impact/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ball_block/edit_remove_block_after_impact.jpg"
    },
    {
      "global_id": "ball_box_rebound/edit_dead_ball",
      "scene": "ball_box_rebound",
      "case_id": "edit_dead_ball",
      "source_case_id": "ball_box_rebound_baseline",
      "source_video": "scenes/ball_box_rebound/cases/ball_box_rebound_baseline/video.mp4",
      "edited_video": "scenes/ball_box_rebound/cases/edit_dead_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把星星球的恢复系数调小一些。",
          "en": "From the start of the clip, decrease the star ball's restitution."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把星星球的恢复系数减少到原来的 0.25 倍。",
          "en": "From frame 1 onwards, reduce the star ball's restitution to 0.25 times its original value."
        }
      },
      "edit_dsl": "SET ball_a.restitution TIMES 0.25",
      "edit_kind": "SET",
      "object_id": "ball_a",
      "property": "restitution",
      "outcome_type": "restitution_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "restitution (ball_a)": {
          "from": 0.88,
          "to": 0.22
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Star ball made far less bouncy, so its rebound off the chest panel flattens out and it comes away on a much shallower line. It runs 1.66 m from its start against the baseline's 1.10 m and misses the football entirely: the little football never moves, where the baseline nudges it 0.30 m.",
      "ground_truth": "scenes/ball_box_rebound/cases/edit_dead_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ball_box_rebound/edit_dead_ball.jpg"
    },
    {
      "global_id": "ball_box_rebound/edit_soft_push",
      "scene": "ball_box_rebound",
      "case_id": "edit_soft_push",
      "source_case_id": "ball_box_rebound_baseline",
      "source_video": "scenes/ball_box_rebound/cases/ball_box_rebound_baseline/video.mp4",
      "edited_video": "scenes/ball_box_rebound/cases/edit_soft_push/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把星星球的初速度大小调小一些。",
          "en": "From the start of the clip, decrease the star ball's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把星星球的初速度大小减少到原来的 0.75 倍。",
          "en": "From frame 1 onwards, reduce the star ball's initial speed to 0.75 times its original value."
        }
      },
      "edit_dsl": "SET ball_a.initial_velocity TIMES 0.75",
      "edit_kind": "SET",
      "object_id": "ball_a",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (ball_a)": {
          "from": 2.6,
          "to": 1.95
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "A gentler push, aimed identically. This is the suite's distractor: the bounce geometry is untouched -- 29.4 deg out against the source's 29.2, because speed does not bend the rebound -- and the ball still reaches the football. But everything happens later and weaker: the chest is met on frame 17 instead of 13, the football on frame 38 instead of 24, and it is nudged 0.05 m rather than knocked 0.30 m clear.",
      "ground_truth": "scenes/ball_box_rebound/cases/edit_soft_push/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ball_box_rebound/edit_soft_push.jpg"
    },
    {
      "global_id": "ball_box_rebound/edit_draggy_ball",
      "scene": "ball_box_rebound",
      "case_id": "edit_draggy_ball",
      "source_case_id": "ball_box_rebound_baseline",
      "source_video": "scenes/ball_box_rebound/cases/ball_box_rebound_baseline/video.mp4",
      "edited_video": "scenes/ball_box_rebound/cases/edit_draggy_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把星星球的摩擦系数调大一些。",
          "en": "From the start of the clip, increase the star ball's friction coefficient."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把星星球的摩擦系数增加到原来的 5 倍。",
          "en": "From frame 1 onwards, increase the star ball's friction coefficient to 5 times its original value."
        }
      },
      "edit_dsl": "SET ball_a.friction TIMES 5",
      "edit_kind": "SET",
      "object_id": "ball_a",
      "property": "friction",
      "outcome_type": "friction_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "friction (ball_a)": {
          "from": 1.0,
          "to": 5.0
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "The rolling ball made to drag on the boards -- a scuffed, tacky ball rather than a changed floor. Because Bullet builds rolling resistance from `rf_floor * lateral_ball` and the ball carries no rolling friction of its own, this raises the effective resistance from 0.006 to 0.030 while leaving the bounce off the chest alone. The ball loses most of the run-up before it arrives: it reaches the chest on frame 18 at 0.85 m/s instead of frame 13 at 2.36 m/s. It still bounces, and still at 30.0 deg, but comes off with so little left that it stops short of the football and settles by frame 22, less than a second into the shot.",
      "ground_truth": "scenes/ball_box_rebound/cases/edit_draggy_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ball_box_rebound/edit_draggy_ball.jpg"
    },
    {
      "global_id": "ball_box_rebound/edit_heavy_target",
      "scene": "ball_box_rebound",
      "case_id": "edit_heavy_target",
      "source_case_id": "ball_box_rebound_baseline",
      "source_video": "scenes/ball_box_rebound/cases/ball_box_rebound_baseline/video.mp4",
      "edited_video": "scenes/ball_box_rebound/cases/edit_heavy_target/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把小足球的质量调大一些。",
          "en": "From the start of the clip, increase the little football's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把小足球的质量增加到原来的 10 倍。",
          "en": "From frame 1 onwards, increase the little football's mass to 10 times its original value."
        }
      },
      "edit_dsl": "SET ball_b.mass TIMES 10",
      "edit_kind": "SET",
      "object_id": "ball_b",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (ball_b)": {
          "from": 0.09,
          "to": 0.9
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "The football made 10x heavier. The roll, the bounce and the rebound line are identical to the source, and the ball still arrives at 1.10 m/s -- but the football barely twitches, moving 0.013 m instead of 0.300, and the star ball rebounds back off it at 0.57 m/s instead of stopping dead at 0.19.",
      "ground_truth": "scenes/ball_box_rebound/cases/edit_heavy_target/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ball_box_rebound/edit_heavy_target.jpg"
    },
    {
      "global_id": "ball_box_rebound/edit_heavy_ball",
      "scene": "ball_box_rebound",
      "case_id": "edit_heavy_ball",
      "source_case_id": "ball_box_rebound_baseline",
      "source_video": "scenes/ball_box_rebound/cases/ball_box_rebound_baseline/video.mp4",
      "edited_video": "scenes/ball_box_rebound/cases/edit_heavy_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把星星球的质量调大一些。",
          "en": "From the start of the clip, increase the star ball's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把星星球的质量增加到原来的 10 倍。",
          "en": "From frame 1 onwards, increase the star ball's mass to 10 times its original value."
        }
      },
      "edit_dsl": "SET ball_a.mass TIMES 10",
      "edit_kind": "SET",
      "object_id": "ball_a",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (ball_a)": {
          "from": 0.12,
          "to": 1.2
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "The rolling ball made 10x heavier. The bounce off the chest is unchanged -- restitution sets the rebound, not mass -- but the ball-on-ball hit is one-sided: the football leaves at 1.65 m/s instead of 0.91 and is driven 0.84 m instead of 0.30, while the star ball carries on through at 0.89 m/s rather than being stopped. Both balls are still rolling when the clip ends.",
      "ground_truth": "scenes/ball_box_rebound/cases/edit_heavy_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ball_box_rebound/edit_heavy_ball.jpg"
    },
    {
      "global_id": "ball_box_rebound/edit_remove_target",
      "scene": "ball_box_rebound",
      "case_id": "edit_remove_target",
      "source_case_id": "ball_box_rebound_baseline",
      "source_video": "scenes/ball_box_rebound/cases/ball_box_rebound_baseline/video.mp4",
      "edited_video": "scenes/ball_box_rebound/cases/edit_remove_target/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把小足球从场景中删除。",
          "en": "From the start of the clip, remove the little football from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把小足球从场景中删除。",
          "en": "From frame 1 onwards, remove the little football from the scene."
        }
      },
      "edit_dsl": "DELETE ball_b",
      "edit_kind": "DELETE",
      "object_id": "ball_b",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "ball_b": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "The football removed. The roll and the bounce are identical to the source, and then the rebound crosses empty floor: with nothing to hit, the ball keeps its 1.72 m/s and rolls on towards the camera, leaving frame at the bottom edge around frame 48 and coming to rest off-camera. The last second of the clip is bare floor.",
      "ground_truth": "scenes/ball_box_rebound/cases/edit_remove_target/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ball_box_rebound/edit_remove_target.jpg"
    },
    {
      "global_id": "ball_box_rebound/edit_remove_target_after_impact",
      "scene": "ball_box_rebound",
      "case_id": "edit_remove_target_after_impact",
      "source_case_id": "ball_box_rebound_baseline",
      "source_video": "scenes/ball_box_rebound/cases/ball_box_rebound_baseline/video.mp4",
      "edited_video": "scenes/ball_box_rebound/cases/edit_remove_target_after_impact/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "在视频前段,把小足球从场景中删除。",
          "en": "Early in the clip, remove the little football from the scene."
        },
        "quantitative": {
          "zh": "从第 32 帧开始,把小足球从场景中删除。",
          "en": "From frame 32 onwards, remove the little football from the scene."
        }
      },
      "edit_dsl": "DELETE ball_b AT FRAME 32",
      "edit_kind": "DELETE",
      "object_id": "ball_b",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 32,
      "timing": "partway",
      "physics_diff": {
        "ball_b": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 32,
          "total_frames": 96,
          "unedited_frames": [
            1,
            31
          ]
        }
      },
      "edit_summary": "Football removed at frame 32, eight frames after the star ball reaches it at frame 24. Frames 1-31 are the source video frame for frame: the star ball rebounds off the toy chest at frame 13, runs into the football and is left creeping at 0.07 m/s, and the football has been driven 0.18 m when it disappears. The star ball then settles at (+0.27, +0.62) exactly as in the source. The whole-clip version of the same delete is a different video again: with no football to hit, the star ball keeps 1.0 m/s off the rebound and coasts out to (+0.99, +1.39).",
      "ground_truth": "scenes/ball_box_rebound/cases/edit_remove_target_after_impact/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ball_box_rebound/edit_remove_target_after_impact.jpg"
    },
    {
      "global_id": "ball_carpet_climb/edit_grippy_ball",
      "scene": "ball_carpet_climb",
      "case_id": "edit_grippy_ball",
      "source_case_id": "ball_carpet_climb_baseline",
      "source_video": "scenes/ball_carpet_climb/cases/ball_carpet_climb_baseline/video.mp4",
      "edited_video": "scenes/ball_carpet_climb/cases/edit_grippy_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把排球的摩擦系数调大一些。",
          "en": "From the start of the clip, increase the volleyball's friction coefficient."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把排球的摩擦系数增加到原来的 3 倍。",
          "en": "From frame 1 onwards, increase the volleyball's friction coefficient to 3 times its original value."
        }
      },
      "edit_dsl": "SET ball.friction TIMES 3",
      "edit_kind": "SET",
      "object_id": "ball",
      "property": "friction",
      "outcome_type": "friction_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "friction (ball)": {
          "from": 1.0,
          "to": 3.0
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Ball made much grippier (friction 3x). It rolls the same bare floor in, but the moment it touches the rug the extra rolling resistance kills it: instead of the 0.49 m mid-rug rest it barely creeps 0.16 m past the rug edge before stopping.",
      "ground_truth": "scenes/ball_carpet_climb/cases/edit_grippy_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ball_carpet_climb/edit_grippy_ball.jpg"
    },
    {
      "global_id": "ball_carpet_climb/edit_slippy_ball",
      "scene": "ball_carpet_climb",
      "case_id": "edit_slippy_ball",
      "source_case_id": "ball_carpet_climb_baseline",
      "source_video": "scenes/ball_carpet_climb/cases/ball_carpet_climb_baseline/video.mp4",
      "edited_video": "scenes/ball_carpet_climb/cases/edit_slippy_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把排球的摩擦系数调小一些。",
          "en": "From the start of the clip, decrease the volleyball's friction coefficient."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把排球的摩擦系数减少到原来的 0.3 倍。",
          "en": "From frame 1 onwards, reduce the volleyball's friction coefficient to 0.3 times its original value."
        }
      },
      "edit_dsl": "SET ball.friction TIMES 0.3",
      "edit_kind": "SET",
      "object_id": "ball",
      "property": "friction",
      "outcome_type": "friction_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "friction (ball)": {
          "from": 1.0,
          "to": 0.3
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Ball made much slicker (friction 0.3x). The rug barely slows it: it coasts across the full 1.11 m of pile and comes to rest against the front of the sofa, rather than stopping halfway across the rug.",
      "ground_truth": "scenes/ball_carpet_climb/cases/edit_slippy_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ball_carpet_climb/edit_slippy_ball.jpg"
    },
    {
      "global_id": "ball_carpet_climb/edit_soft_push",
      "scene": "ball_carpet_climb",
      "case_id": "edit_soft_push",
      "source_case_id": "ball_carpet_climb_baseline",
      "source_video": "scenes/ball_carpet_climb/cases/ball_carpet_climb_baseline/video.mp4",
      "edited_video": "scenes/ball_carpet_climb/cases/edit_soft_push/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把排球的初速度大小调小一些。",
          "en": "From the start of the clip, decrease the volleyball's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把排球的初速度大小减少到原来的 0.6 倍。",
          "en": "From frame 1 onwards, reduce the volleyball's initial speed to 0.6 times its original value."
        }
      },
      "edit_dsl": "SET ball.initial_velocity TIMES 0.6",
      "edit_kind": "SET",
      "object_id": "ball",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (ball)": {
          "from": 2.05,
          "to": 1.23
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Gentler push. The ball reaches the rug at 1.23 m/s instead of 2.05 and stalls soon after the border, covering 0.75 m against the baseline's 1.09 -- a rug-edge stall driven by the weaker start, not by a grippier surface.",
      "ground_truth": "scenes/ball_carpet_climb/cases/edit_soft_push/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ball_carpet_climb/edit_soft_push.jpg"
    },
    {
      "global_id": "ball_carpet_climb/edit_hard_push",
      "scene": "ball_carpet_climb",
      "case_id": "edit_hard_push",
      "source_case_id": "ball_carpet_climb_baseline",
      "source_video": "scenes/ball_carpet_climb/cases/ball_carpet_climb_baseline/video.mp4",
      "edited_video": "scenes/ball_carpet_climb/cases/edit_hard_push/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把排球的初速度大小调大一些。",
          "en": "From the start of the clip, increase the volleyball's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把排球的初速度大小增加到原来的 1.5 倍。",
          "en": "From frame 1 onwards, increase the volleyball's initial speed to 1.5 times its original value."
        }
      },
      "edit_dsl": "SET ball.initial_velocity TIMES 1.5",
      "edit_kind": "SET",
      "object_id": "ball",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (ball)": {
          "from": 2.05,
          "to": 3.075
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Firmer push. The ball meets the rug at 3.08 m/s instead of 2.05 and carries all the way across the pile, finishing 1.72 m up the room against the baseline's 1.09 m.",
      "ground_truth": "scenes/ball_carpet_climb/cases/edit_hard_push/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ball_carpet_climb/edit_hard_push.jpg"
    },
    {
      "global_id": "bouncing_ball/edit_dead_ball",
      "scene": "bouncing_ball",
      "case_id": "edit_dead_ball",
      "source_case_id": "bouncing_ball_baseline",
      "source_video": "scenes/bouncing_ball/cases/bouncing_ball_baseline/video.mp4",
      "edited_video": "scenes/bouncing_ball/cases/edit_dead_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把红球的恢复系数调小一些。",
          "en": "From the start of the clip, decrease the red ball's restitution."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把红球的恢复系数减少到原来的 0.4 倍。",
          "en": "From frame 1 onwards, reduce the red ball's restitution to 0.4 times its original value."
        }
      },
      "edit_dsl": "SET ball.restitution TIMES 0.4",
      "edit_kind": "SET",
      "object_id": "ball",
      "property": "restitution",
      "outcome_type": "restitution_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "restitution (ball)": {
          "from": 0.78,
          "to": 0.312
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Ball made much less elastic. The bounce chain collapses: two hops instead of seven, a 2.04 m path over the clip against the baseline's 5.98 m, and the ball is down to 0.07 m/s at the end where the baseline is still running at 0.87. First floor contact is unchanged at frame 13.",
      "ground_truth": "scenes/bouncing_ball/cases/edit_dead_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/bouncing_ball/edit_dead_ball.jpg"
    },
    {
      "global_id": "bouncing_ball/edit_super_bouncy",
      "scene": "bouncing_ball",
      "case_id": "edit_super_bouncy",
      "source_case_id": "bouncing_ball_baseline",
      "source_video": "scenes/bouncing_ball/cases/bouncing_ball_baseline/video.mp4",
      "edited_video": "scenes/bouncing_ball/cases/edit_super_bouncy/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把红球的恢复系数调大一些。",
          "en": "From the start of the clip, increase the red ball's restitution."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把红球的恢复系数增加到原来的 1.2 倍。",
          "en": "From frame 1 onwards, increase the red ball's restitution to 1.2 times its original value."
        }
      },
      "edit_dsl": "SET ball.restitution TIMES 1.2",
      "edit_kind": "SET",
      "object_id": "ball",
      "property": "restitution",
      "outcome_type": "restitution_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "restitution (ball)": {
          "from": 0.78,
          "to": 0.936
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Ball made near-elastic. The bounce chain barely decays: the ball covers a 9.00 m path against the baseline's 5.98 m, and at the end of the clip it is still airborne at 1.25 m -- most of the way back to its 1.57 m release height -- and still moving at 1.09 m/s.",
      "ground_truth": "scenes/bouncing_ball/cases/edit_super_bouncy/ground_truth_transforms.json",
      "thumbnail": "thumbnails/bouncing_ball/edit_super_bouncy.jpg"
    },
    {
      "global_id": "bouncing_ball/edit_no_push",
      "scene": "bouncing_ball",
      "case_id": "edit_no_push",
      "source_case_id": "bouncing_ball_baseline",
      "source_video": "scenes/bouncing_ball/cases/bouncing_ball_baseline/video.mp4",
      "edited_video": "scenes/bouncing_ball/cases/edit_no_push/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,让红球保持静止。",
          "en": "From the start of the clip, leave the red ball at rest."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,让红球保持静止。",
          "en": "From frame 1 onwards, leave the red ball at rest."
        }
      },
      "edit_dsl": "SET ball.initial_velocity TIMES 0",
      "edit_kind": "SET",
      "object_id": "ball",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (ball)": {
          "from": 0.5,
          "to": 0.0
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Horizontal push removed. The ball drops straight down and bounces in place at x ~ 0 instead of drifting the ~0.29 m across the floor seen in the baseline.",
      "ground_truth": "scenes/bouncing_ball/cases/edit_no_push/ground_truth_transforms.json",
      "thumbnail": "thumbnails/bouncing_ball/edit_no_push.jpg"
    },
    {
      "global_id": "bouncing_ball/edit_strong_push",
      "scene": "bouncing_ball",
      "case_id": "edit_strong_push",
      "source_case_id": "bouncing_ball_baseline",
      "source_video": "scenes/bouncing_ball/cases/bouncing_ball_baseline/video.mp4",
      "edited_video": "scenes/bouncing_ball/cases/edit_strong_push/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把红球的初速度大小调大一些。",
          "en": "From the start of the clip, increase the red ball's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把红球的初速度大小增加到原来的 6 倍。",
          "en": "From frame 1 onwards, increase the red ball's initial speed to 6 times its original value."
        }
      },
      "edit_dsl": "SET ball.initial_velocity TIMES 6",
      "edit_kind": "SET",
      "object_id": "ball",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (ball)": {
          "from": 0.5,
          "to": 3.0
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Horizontal push made 6x stronger. The ball crosses the room and ends the clip at x ~ +4.4 m instead of the baseline +0.29 m, bouncing along the way.",
      "ground_truth": "scenes/bouncing_ball/cases/edit_strong_push/ground_truth_transforms.json",
      "thumbnail": "thumbnails/bouncing_ball/edit_strong_push.jpg"
    },
    {
      "global_id": "bouncing_ball/edit_dead_ball_after_first_bounce",
      "scene": "bouncing_ball",
      "case_id": "edit_dead_ball_after_first_bounce",
      "source_case_id": "bouncing_ball_baseline",
      "source_video": "scenes/bouncing_ball/cases/bouncing_ball_baseline/video.mp4",
      "edited_video": "scenes/bouncing_ball/cases/edit_dead_ball_after_first_bounce/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "在视频前段,把红球的恢复系数调小一些。",
          "en": "Early in the clip, decrease the red ball's restitution."
        },
        "quantitative": {
          "zh": "从第 20 帧开始,把红球的恢复系数减少到原来的 0.1 倍。",
          "en": "From frame 20 onwards, reduce the red ball's restitution to 0.1 times its original value."
        }
      },
      "edit_dsl": "SET ball.restitution TIMES 0.1 AT FRAME 20",
      "edit_kind": "SET",
      "object_id": "ball",
      "property": "restitution",
      "outcome_type": "restitution_decrease",
      "applies_from_frame": 20,
      "timing": "partway",
      "physics_diff": {
        "restitution (ball)": {
          "from": 0.78,
          "to": 0.078
        },
        "timing": {
          "applies_from_frame": 20,
          "total_frames": 96,
          "unedited_frames": [
            1,
            19
          ]
        }
      },
      "edit_summary": "Ball made much less elastic at frame 20, while it is airborne between its first and second bounce. Frames 1-19 are the source video frame for frame: the ball falls, hits the floor at frame 13 and rebounds to the same 0.86 m apex at frame 23. The second landing is where the edit shows -- it barely leaves the floor (0.06 m at frame 34) and the ball is at rest for the rest of the clip, against the baseline's six apexes. The whole-clip version of the same edit kills the first bounce too: the ball never gets above 0.06 m at all.",
      "ground_truth": "scenes/bouncing_ball/cases/edit_dead_ball_after_first_bounce/ground_truth_transforms.json",
      "thumbnail": "thumbnails/bouncing_ball/edit_dead_ball_after_first_bounce.jpg"
    },
    {
      "global_id": "bowling/edit_light_ball",
      "scene": "bowling",
      "case_id": "edit_light_ball",
      "source_case_id": "bowling_baseline",
      "source_video": "scenes/bowling/cases/bowling_baseline/video.mp4",
      "edited_video": "scenes/bowling/cases/edit_light_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把保龄球的质量调小一些。",
          "en": "From the start of the clip, decrease the bowling ball's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把保龄球的质量减少到原来的 0.2 倍。",
          "en": "From frame 1 onwards, reduce the bowling ball's mass to 0.2 times its original value."
        }
      },
      "edit_dsl": "SET ball.mass TIMES 0.2",
      "edit_kind": "SET",
      "object_id": "ball",
      "property": "mass",
      "outcome_type": "mass_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (ball)": {
          "from": 3.0,
          "to": 0.6
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Ball made five times lighter. It no longer ploughs through the rack: the pins take 2.02 m of travel between them against the baseline's 6.67 m, and the head pin in particular moves 0.55 m instead of 4.08 m. The ball itself stops at the pin line after 10.00 m, where the baseline carries 14.35 m and is still running at 1.59 m/s at the end.",
      "ground_truth": "scenes/bowling/cases/edit_light_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/bowling/edit_light_ball.jpg"
    },
    {
      "global_id": "bowling/edit_heavy_pins",
      "scene": "bowling",
      "case_id": "edit_heavy_pins",
      "source_case_id": "bowling_baseline",
      "source_video": "scenes/bowling/cases/bowling_baseline/video.mp4",
      "edited_video": "scenes/bowling/cases/edit_heavy_pins/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把保龄球瓶的质量调大一些。",
          "en": "From the start of the clip, increase the bowling pin set's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把保龄球瓶的质量增加到原来的 25 倍。",
          "en": "From frame 1 onwards, increase the bowling pin set's mass to 25 times its original value."
        }
      },
      "edit_dsl": "SET pins.mass TIMES 25",
      "edit_kind": "SET",
      "object_id": "pins",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (pins)": {
          "from": 0.8,
          "to": 20.0
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Pins made 25x heavier -- effectively immovable. No pins are knocked; the ball bounces straight back off the front pin and the standing formation is preserved.",
      "ground_truth": "scenes/bowling/cases/edit_heavy_pins/ground_truth_transforms.json",
      "thumbnail": "thumbnails/bowling/edit_heavy_pins.jpg"
    },
    {
      "global_id": "bowling/edit_grippy_ball",
      "scene": "bowling",
      "case_id": "edit_grippy_ball",
      "source_case_id": "bowling_baseline",
      "source_video": "scenes/bowling/cases/bowling_baseline/video.mp4",
      "edited_video": "scenes/bowling/cases/edit_grippy_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把保龄球的摩擦系数调大一些。",
          "en": "From the start of the clip, increase the bowling ball's friction coefficient."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把保龄球的摩擦系数增加到原来的 5 倍。",
          "en": "From frame 1 onwards, increase the bowling ball's friction coefficient to 5 times its original value."
        }
      },
      "edit_dsl": "SET ball.friction TIMES 5",
      "edit_kind": "SET",
      "object_id": "ball",
      "property": "friction",
      "outcome_type": "friction_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "friction (ball)": {
          "from": 0.4,
          "to": 2.0
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Ball made 5x grippier. Lane friction eats it during the roll: it reaches the pins with far less speed, only nudges the front pin, and stops near x=0 instead of continuing on through to x~-2.7.",
      "ground_truth": "scenes/bowling/cases/edit_grippy_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/bowling/edit_grippy_ball.jpg"
    },
    {
      "global_id": "bowling/edit_slippery_pins",
      "scene": "bowling",
      "case_id": "edit_slippery_pins",
      "source_case_id": "bowling_baseline",
      "source_video": "scenes/bowling/cases/bowling_baseline/video.mp4",
      "edited_video": "scenes/bowling/cases/edit_slippery_pins/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把保龄球瓶的摩擦系数调小一些。",
          "en": "From the start of the clip, decrease the bowling pin set's friction coefficient."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把保龄球瓶的摩擦系数减少到原来的 0.125 倍。",
          "en": "From frame 1 onwards, reduce the bowling pin set's friction coefficient to 0.125 times its original value."
        }
      },
      "edit_dsl": "SET pins.friction TIMES 0.125",
      "edit_kind": "SET",
      "object_id": "pins",
      "property": "friction",
      "outcome_type": "friction_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "friction (pins)": {
          "from": 0.4,
          "to": 0.05
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Pin/lane friction dropped to near-zero. Knocked pins skate across the lane instead of tumbling to a stop: total pin displacement rises to ~8.7 m and pins end the clip much farther from their spots.",
      "ground_truth": "scenes/bowling/cases/edit_slippery_pins/ground_truth_transforms.json",
      "thumbnail": "thumbnails/bowling/edit_slippery_pins.jpg"
    },
    {
      "global_id": "car_gap_jump/edit_underpowered",
      "scene": "car_gap_jump",
      "case_id": "edit_underpowered",
      "source_case_id": "car_gap_jump_baseline",
      "source_video": "scenes/car_gap_jump/cases/car_gap_jump_baseline/video.mp4",
      "edited_video": "scenes/car_gap_jump/cases/edit_underpowered/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把玩具车的初速度大小调小一些。",
          "en": "From the start of the clip, decrease the toy car's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把玩具车的初速度大小减少到原来的 0.75 倍。",
          "en": "From frame 1 onwards, reduce the toy car's initial speed to 0.75 times its original value."
        }
      },
      "edit_dsl": "SET car.initial_velocity TIMES 0.75",
      "edit_kind": "SET",
      "object_id": "car",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (car)": {
          "from": 1.9,
          "to": 1.425
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Push weakened below the clearance threshold. The car noses off the book stack but its arc falls short of the far table and it drops into the gap, landing on the room floor at x=+0.01 against the baseline's upright landing on the far table at x=+0.87.",
      "ground_truth": "scenes/car_gap_jump/cases/edit_underpowered/ground_truth_transforms.json",
      "thumbnail": "thumbnails/car_gap_jump/edit_underpowered.jpg"
    },
    {
      "global_id": "car_gap_jump/edit_overpowered",
      "scene": "car_gap_jump",
      "case_id": "edit_overpowered",
      "source_case_id": "car_gap_jump_baseline",
      "source_video": "scenes/car_gap_jump/cases/car_gap_jump_baseline/video.mp4",
      "edited_video": "scenes/car_gap_jump/cases/edit_overpowered/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把玩具车的初速度大小调大一些。",
          "en": "From the start of the clip, increase the toy car's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把玩具车的初速度大小增加到原来的 2 倍。",
          "en": "From frame 1 onwards, increase the toy car's initial speed to 2 times its original value."
        }
      },
      "edit_dsl": "SET car.initial_velocity TIMES 2",
      "edit_kind": "SET",
      "object_id": "car",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (car)": {
          "from": 1.9,
          "to": 3.8
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Push doubled. The car clears the gap easily but has so much speed left that it skids straight off the far table: it ends the clip on the room floor at x=+3.22, 3.53 m from where it started, against the baseline's tidy landing on the far table at x=+0.87.",
      "ground_truth": "scenes/car_gap_jump/cases/edit_overpowered/ground_truth_transforms.json",
      "thumbnail": "thumbnails/car_gap_jump/edit_overpowered.jpg"
    },
    {
      "global_id": "car_gap_jump/edit_slippery_wheels",
      "scene": "car_gap_jump",
      "case_id": "edit_slippery_wheels",
      "source_case_id": "car_gap_jump_baseline",
      "source_video": "scenes/car_gap_jump/cases/car_gap_jump_baseline/video.mp4",
      "edited_video": "scenes/car_gap_jump/cases/edit_slippery_wheels/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把玩具车的摩擦系数调小一些。",
          "en": "From the start of the clip, decrease the toy car's friction coefficient."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把玩具车的摩擦系数减少到原来的 0.3 倍。",
          "en": "From frame 1 onwards, reduce the toy car's friction coefficient to 0.3 times its original value."
        }
      },
      "edit_dsl": "SET car.friction TIMES 0.3",
      "edit_kind": "SET",
      "object_id": "car",
      "property": "friction",
      "outcome_type": "friction_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "friction (car)": {
          "from": 0.45,
          "to": 0.135
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Car friction cut to less than a third. It scrubs almost nothing off on the launch deck and reaches the edge far faster than the source, so it clears the gap and keeps going: it slides straight off the far table and ends the clip upright on the room floor at x=+2.78, 3.11 m from where it started, against the baseline's tidy landing on the far table at x=+0.87.",
      "ground_truth": "scenes/car_gap_jump/cases/edit_slippery_wheels/ground_truth_transforms.json",
      "thumbnail": "thumbnails/car_gap_jump/edit_slippery_wheels.jpg"
    },
    {
      "global_id": "car_gap_jump/edit_grippy_wheels",
      "scene": "car_gap_jump",
      "case_id": "edit_grippy_wheels",
      "source_case_id": "car_gap_jump_baseline",
      "source_video": "scenes/car_gap_jump/cases/car_gap_jump_baseline/video.mp4",
      "edited_video": "scenes/car_gap_jump/cases/edit_grippy_wheels/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把玩具车的摩擦系数调大一些。",
          "en": "From the start of the clip, increase the toy car's friction coefficient."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把玩具车的摩擦系数增加到原来的 7 倍。",
          "en": "From frame 1 onwards, increase the toy car's friction coefficient to 7 times its original value."
        }
      },
      "edit_dsl": "SET car.friction TIMES 7",
      "edit_kind": "SET",
      "object_id": "car",
      "property": "friction",
      "outcome_type": "friction_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "friction (car)": {
          "from": 0.45,
          "to": 3.15
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Car friction cranked up sevenfold. The deck scrubs so much speed off the roll-up that the car cannot clear the gap: it drops off the near edge and lands upside down on the room floor 0.89 m below, at x=+0.22, where the baseline lands upright on the far table at x=+0.87.",
      "ground_truth": "scenes/car_gap_jump/cases/edit_grippy_wheels/ground_truth_transforms.json",
      "thumbnail": "thumbnails/car_gap_jump/edit_grippy_wheels.jpg"
    },
    {
      "global_id": "car_gap_jump/edit_grippy_wheels_mid_jump",
      "scene": "car_gap_jump",
      "case_id": "edit_grippy_wheels_mid_jump",
      "source_case_id": "car_gap_jump_baseline",
      "source_video": "scenes/car_gap_jump/cases/car_gap_jump_baseline/video.mp4",
      "edited_video": "scenes/car_gap_jump/cases/edit_grippy_wheels_mid_jump/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "在视频前段,把玩具车的摩擦系数调大一些。",
          "en": "Early in the clip, increase the toy car's friction coefficient."
        },
        "quantitative": {
          "zh": "从第 6 帧开始,把玩具车的摩擦系数增加到原来的 7 倍。",
          "en": "From frame 6 onwards, increase the toy car's friction coefficient to 7 times its original value."
        }
      },
      "edit_dsl": "SET car.friction TIMES 7 AT FRAME 6",
      "edit_kind": "SET",
      "object_id": "car",
      "property": "friction",
      "outcome_type": "friction_increase",
      "applies_from_frame": 6,
      "timing": "partway",
      "physics_diff": {
        "friction (car)": {
          "from": 0.45,
          "to": 3.15
        },
        "timing": {
          "applies_from_frame": 6,
          "total_frames": 96,
          "unedited_frames": [
            1,
            5
          ]
        }
      },
      "edit_summary": "Wheel friction raised sevenfold at frame 6, with the car already off the near table and in the air. Frames 1-5 are the source video frame for frame, take-off included, and the flight is unchanged -- friction does nothing until something is touched. The landing is where it shows: instead of sliding out onto the far table and coasting to x=+0.78, the tyres grip the far lip, the car trips over it and drops into the gap, ending upside down at z=-0.71. The whole-clip version of the same factor is a different video again: the car never gets moving and falls straight into the gap from the near edge.",
      "ground_truth": "scenes/car_gap_jump/cases/edit_grippy_wheels_mid_jump/ground_truth_transforms.json",
      "thumbnail": "thumbnails/car_gap_jump/edit_grippy_wheels_mid_jump.jpg"
    },
    {
      "global_id": "car_ramp_climb/edit_underpowered",
      "scene": "car_ramp_climb",
      "case_id": "edit_underpowered",
      "source_case_id": "car_ramp_climb_baseline",
      "source_video": "scenes/car_ramp_climb/cases/car_ramp_climb_baseline/video.mp4",
      "edited_video": "scenes/car_ramp_climb/cases/edit_underpowered/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把玩具车的初速度大小调小一些。",
          "en": "From the start of the clip, decrease the toy car's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把玩具车的初速度大小减少到原来的 0.6 倍。",
          "en": "From frame 1 onwards, reduce the toy car's initial speed to 0.6 times its original value."
        }
      },
      "edit_dsl": "SET car.initial_velocity TIMES 0.6",
      "edit_kind": "SET",
      "object_id": "car",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (car)": {
          "from": 2.7,
          "to": 1.62
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Push weakened well below the crest threshold. The car climbs part of the ramp, stalls, and slides back down under gravity, coming to rest on the floor behind where it set off -- x=+0.97 against a start of x=+0.32. The baseline clears the ramp and lands past it at x=-0.73.",
      "ground_truth": "scenes/car_ramp_climb/cases/edit_underpowered/ground_truth_transforms.json",
      "thumbnail": "thumbnails/car_ramp_climb/edit_underpowered.jpg"
    },
    {
      "global_id": "car_ramp_climb/edit_underrotate_flip",
      "scene": "car_ramp_climb",
      "case_id": "edit_underrotate_flip",
      "source_case_id": "car_ramp_climb_baseline",
      "source_video": "scenes/car_ramp_climb/cases/car_ramp_climb_baseline/video.mp4",
      "edited_video": "scenes/car_ramp_climb/cases/edit_underrotate_flip/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把玩具车的初速度大小调小一些。",
          "en": "From the start of the clip, decrease the toy car's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把玩具车的初速度大小减少到原来的 0.95 倍。",
          "en": "From frame 1 onwards, reduce the toy car's initial speed to 0.95 times its original value."
        }
      },
      "edit_dsl": "SET car.initial_velocity TIMES 0.95",
      "edit_kind": "SET",
      "object_id": "car",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (car)": {
          "from": 2.7,
          "to": 2.565
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Push dropped from 2.7 to 2.565 m/s, just across the flip threshold. The car still clears the ramp and lands past it -- 1.09 m from its start at x=-0.77, against the baseline's 1.05 m to x=-0.73 -- but it has enough less airtime that it under-rotates and comes down on its roof rather than bottom-down. The landing spot barely moves; only the orientation flips.",
      "ground_truth": "scenes/car_ramp_climb/cases/edit_underrotate_flip/ground_truth_transforms.json",
      "thumbnail": "thumbnails/car_ramp_climb/edit_underrotate_flip.jpg"
    },
    {
      "global_id": "car_ramp_climb/edit_grippy_wheels",
      "scene": "car_ramp_climb",
      "case_id": "edit_grippy_wheels",
      "source_case_id": "car_ramp_climb_baseline",
      "source_video": "scenes/car_ramp_climb/cases/car_ramp_climb_baseline/video.mp4",
      "edited_video": "scenes/car_ramp_climb/cases/edit_grippy_wheels/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把玩具车的摩擦系数调大一些。",
          "en": "From the start of the clip, increase the toy car's friction coefficient."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把玩具车的摩擦系数增加到原来的 4 倍。",
          "en": "From frame 1 onwards, increase the toy car's friction coefficient to 4 times its original value."
        }
      },
      "edit_dsl": "SET car.friction TIMES 4",
      "edit_kind": "SET",
      "object_id": "car",
      "property": "friction",
      "outcome_type": "friction_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "friction (car)": {
          "from": 0.25,
          "to": 1.0
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Pair friction between car and ramp raised fourfold -- what a grip-tape surface would give. The wheels bite so hard that the car advances only 0.29 m and stops part-way up the ramp at x=+0.05, still tilted on the face, instead of launching off the top and landing past it at x=-0.73.",
      "ground_truth": "scenes/car_ramp_climb/cases/edit_grippy_wheels/ground_truth_transforms.json",
      "thumbnail": "thumbnails/car_ramp_climb/edit_grippy_wheels.jpg"
    },
    {
      "global_id": "car_ramp_climb/edit_slick_wheels",
      "scene": "car_ramp_climb",
      "case_id": "edit_slick_wheels",
      "source_case_id": "car_ramp_climb_baseline",
      "source_video": "scenes/car_ramp_climb/cases/car_ramp_climb_baseline/video.mp4",
      "edited_video": "scenes/car_ramp_climb/cases/edit_slick_wheels/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把玩具车的摩擦系数调小一些。",
          "en": "From the start of the clip, decrease the toy car's friction coefficient."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把玩具车的摩擦系数减少到原来的 0.2 倍。",
          "en": "From frame 1 onwards, reduce the toy car's friction coefficient to 0.2 times its original value."
        }
      },
      "edit_dsl": "SET car.friction TIMES 0.2",
      "edit_kind": "SET",
      "object_id": "car",
      "property": "friction",
      "outcome_type": "friction_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "friction (car)": {
          "from": 0.25,
          "to": 0.05
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Pair friction dropped 5x -- effectively an ice-slick ramp. The car loses almost no speed on the way up, launches off the top with a lot to spare, and coasts far past the ramp: climb=2.37 m (baseline 0.96 m), final_x=-2.05, and it is still drifting at 0.13 m/s when the clip ends.",
      "ground_truth": "scenes/car_ramp_climb/cases/edit_slick_wheels/ground_truth_transforms.json",
      "thumbnail": "thumbnails/car_ramp_climb/edit_slick_wheels.jpg"
    },
    {
      "global_id": "car_ramp_climb/edit_grippy_wheels_mid_climb",
      "scene": "car_ramp_climb",
      "case_id": "edit_grippy_wheels_mid_climb",
      "source_case_id": "car_ramp_climb_baseline",
      "source_video": "scenes/car_ramp_climb/cases/car_ramp_climb_baseline/video.mp4",
      "edited_video": "scenes/car_ramp_climb/cases/edit_grippy_wheels_mid_climb/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "在视频前段,把玩具车的摩擦系数调大一些。",
          "en": "Early in the clip, increase the toy car's friction coefficient."
        },
        "quantitative": {
          "zh": "从第 8 帧开始,把玩具车的摩擦系数增加到原来的 8 倍。",
          "en": "From frame 8 onwards, increase the toy car's friction coefficient to 8 times its original value."
        }
      },
      "edit_dsl": "SET car.friction TIMES 8 AT FRAME 8",
      "edit_kind": "SET",
      "object_id": "car",
      "property": "friction",
      "outcome_type": "friction_increase",
      "applies_from_frame": 8,
      "timing": "partway",
      "physics_diff": {
        "friction (car)": {
          "from": 0.25,
          "to": 2.0
        },
        "timing": {
          "applies_from_frame": 8,
          "total_frames": 96,
          "unedited_frames": [
            1,
            7
          ]
        }
      },
      "edit_summary": "Pair friction between car and ramp raised eightfold at frame 8, with the car already a third of the way up. Frames 1-7 are the source video frame for frame. From there the grip stops it dead on the ramp face at x=-0.40, z=0.37, where it sits for the rest of the clip -- it climbs 0.77 m of the baseline's 0.96 m and never reaches the top or lands beyond it at x=-0.73. The whole-clip version of the same factor is a different video again: the car cannot even start the climb and stops at the foot of the ramp at x=+0.26, having moved 0.07 m.",
      "ground_truth": "scenes/car_ramp_climb/cases/edit_grippy_wheels_mid_climb/ground_truth_transforms.json",
      "thumbnail": "thumbnails/car_ramp_climb/edit_grippy_wheels_mid_climb.jpg"
    },
    {
      "global_id": "curling_collision/edit_gentle_launch",
      "scene": "curling_collision",
      "case_id": "edit_gentle_launch",
      "source_case_id": "curling_collision_baseline",
      "source_video": "scenes/curling_collision/cases/curling_collision_baseline/video.mp4",
      "edited_video": "scenes/curling_collision/cases/edit_gentle_launch/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把两只冰壶的初速度大小调小一些。",
          "en": "From the start of the clip, decrease the two stones' initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把两只冰壶的初速度大小减少到原来的 0.3 倍。",
          "en": "From frame 1 onwards, reduce the two stones' initial speed to 0.3 times its original value."
        }
      },
      "edit_dsl": "SET stones.initial_velocity TIMES 0.3",
      "edit_kind": "SET",
      "object_id": "stones",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (stones)": {
          "from": 1.5,
          "to": 0.45
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Both stones launched at 0.45 m/s instead of 1.5. They cover 1.61 m each instead of 2.08 m and are still 1.78 m apart, at x=-0.89 and x=+0.89, when the clip ends -- still drifting at 0.36 m/s but nowhere near meeting. No collision happens at all.",
      "ground_truth": "scenes/curling_collision/cases/edit_gentle_launch/ground_truth_transforms.json",
      "thumbnail": "thumbnails/curling_collision/edit_gentle_launch.jpg"
    },
    {
      "global_id": "curling_collision/edit_heavy_yellow",
      "scene": "curling_collision",
      "case_id": "edit_heavy_yellow",
      "source_case_id": "curling_collision_baseline",
      "source_video": "scenes/curling_collision/cases/curling_collision_baseline/video.mp4",
      "edited_video": "scenes/curling_collision/cases/edit_heavy_yellow/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把黄色冰壶的质量调大一些。",
          "en": "From the start of the clip, increase the yellow stone's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把黄色冰壶的质量增加到原来的 3 倍。",
          "en": "From frame 1 onwards, increase the yellow stone's mass to 3 times its original value."
        }
      },
      "edit_dsl": "SET yellow_stone.mass TIMES 3",
      "edit_kind": "SET",
      "object_id": "yellow_stone",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (yellow_stone)": {
          "from": 20.0,
          "to": 60.0
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Yellow stone made 3x heavier. The head-on impact is no longer balanced: yellow only gives ground to -0.78 m, while red rebounds clear past its own side to -1.30 m -- the opposite of the source, where both stones die at centre.",
      "ground_truth": "scenes/curling_collision/cases/edit_heavy_yellow/ground_truth_transforms.json",
      "thumbnail": "thumbnails/curling_collision/edit_heavy_yellow.jpg"
    },
    {
      "global_id": "curling_collision/edit_light_yellow",
      "scene": "curling_collision",
      "case_id": "edit_light_yellow",
      "source_case_id": "curling_collision_baseline",
      "source_video": "scenes/curling_collision/cases/curling_collision_baseline/video.mp4",
      "edited_video": "scenes/curling_collision/cases/edit_light_yellow/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把黄色冰壶的质量调小一些。",
          "en": "From the start of the clip, decrease the yellow stone's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把黄色冰壶的质量减少到原来的 0.2 倍。",
          "en": "From frame 1 onwards, reduce the yellow stone's mass to 0.2 times its original value."
        }
      },
      "edit_dsl": "SET yellow_stone.mass TIMES 0.2",
      "edit_kind": "SET",
      "object_id": "yellow_stone",
      "property": "mass",
      "outcome_type": "mass_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (yellow_stone)": {
          "from": 20.0,
          "to": 4.0
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Yellow stone made 5x lighter. Momentum from the red stone shoves it clear across the ice to +1.76 m, while the red stone barely slows and keeps going to +1.11 m -- the mirror of edit_heavy_yellow, with the light stone doing the flying.",
      "ground_truth": "scenes/curling_collision/cases/edit_light_yellow/ground_truth_transforms.json",
      "thumbnail": "thumbnails/curling_collision/edit_light_yellow.jpg"
    },
    {
      "global_id": "curling_collision/edit_red_hard_throw",
      "scene": "curling_collision",
      "case_id": "edit_red_hard_throw",
      "source_case_id": "curling_collision_baseline",
      "source_video": "scenes/curling_collision/cases/curling_collision_baseline/video.mp4",
      "edited_video": "scenes/curling_collision/cases/edit_red_hard_throw/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把红色冰壶的初速度大小调大一些。",
          "en": "From the start of the clip, increase the red stone's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把红色冰壶的初速度大小增加到原来的 2 倍。",
          "en": "From frame 1 onwards, increase the red stone's initial speed to 2 times its original value."
        }
      },
      "edit_dsl": "SET red_stone.initial_velocity TIMES 2",
      "edit_kind": "SET",
      "object_id": "red_stone",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (red_stone)": {
          "from": 1.5,
          "to": 3.0
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Red stone launched twice as fast; yellow still 1.5 m/s. The head-on impact is one-sided and happens earlier (frame 26): red carries far more momentum, and both stones end up well past centre on the yellow side (red +1.90, yellow +2.46) -- the source's centred stop is broken.",
      "ground_truth": "scenes/curling_collision/cases/edit_red_hard_throw/ground_truth_transforms.json",
      "thumbnail": "thumbnails/curling_collision/edit_red_hard_throw.jpg"
    },
    {
      "global_id": "curling_collision/edit_red_soft_throw",
      "scene": "curling_collision",
      "case_id": "edit_red_soft_throw",
      "source_case_id": "curling_collision_baseline",
      "source_video": "scenes/curling_collision/cases/curling_collision_baseline/video.mp4",
      "edited_video": "scenes/curling_collision/cases/edit_red_soft_throw/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把红色冰壶的初速度大小调小一些。",
          "en": "From the start of the clip, decrease the red stone's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把红色冰壶的初速度大小减少到原来的 0.5 倍。",
          "en": "From frame 1 onwards, reduce the red stone's initial speed to 0.5 times its original value."
        }
      },
      "edit_dsl": "SET red_stone.initial_velocity TIMES 0.5",
      "edit_kind": "SET",
      "object_id": "red_stone",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (red_stone)": {
          "from": 1.5,
          "to": 0.75
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Red thrown at half the yellow stone's speed. Yellow now carries the exchange: it runs 3.69 m and pushes through to x=-1.19, deep on red's side of centre, while red is turned back -- it covers a 2.29 m path but ends only 0.80 m from where it started, at x=-1.70. The DSL-opposite of edit_red_hard_throw, and a distinct picture: the yellow stone is the one that crosses centre.",
      "ground_truth": "scenes/curling_collision/cases/edit_red_soft_throw/ground_truth_transforms.json",
      "thumbnail": "thumbnails/curling_collision/edit_red_soft_throw.jpg"
    },
    {
      "global_id": "curling_collision/edit_yellow_at_rest",
      "scene": "curling_collision",
      "case_id": "edit_yellow_at_rest",
      "source_case_id": "curling_collision_baseline",
      "source_video": "scenes/curling_collision/cases/curling_collision_baseline/video.mp4",
      "edited_video": "scenes/curling_collision/cases/edit_yellow_at_rest/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,让黄色冰壶保持静止。",
          "en": "From the start of the clip, leave the yellow stone at rest."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,让黄色冰壶保持静止。",
          "en": "From frame 1 onwards, leave the yellow stone at rest."
        }
      },
      "edit_dsl": "SET yellow_stone.initial_velocity TIMES 0",
      "edit_kind": "SET",
      "object_id": "yellow_stone",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (yellow_stone)": {
          "from": 1.5,
          "to": 0.0
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Yellow stone starts at rest instead of sliding in. Red stone launched at the same 1.5 m/s from 5 m away rolls in alone -- but ice friction bleeds it off before it reaches yellow, so it stops at +1.84 m with 0.66 m still between them. No collision happens; yellow never moves.",
      "ground_truth": "scenes/curling_collision/cases/edit_yellow_at_rest/ground_truth_transforms.json",
      "thumbnail": "thumbnails/curling_collision/edit_yellow_at_rest.jpg"
    },
    {
      "global_id": "curling_collision/edit_bouncy_stones",
      "scene": "curling_collision",
      "case_id": "edit_bouncy_stones",
      "source_case_id": "curling_collision_baseline",
      "source_video": "scenes/curling_collision/cases/curling_collision_baseline/video.mp4",
      "edited_video": "scenes/curling_collision/cases/edit_bouncy_stones/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,给两只冰壶一个恢复系数。",
          "en": "From the start of the clip, give the two stones a restitution."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把两只冰壶的恢复系数从 0 改成 0.95。",
          "en": "From frame 1 onwards, change the two stones' restitution from 0 to 0.95."
        }
      },
      "edit_dsl": "SET stones.restitution TO 0.95",
      "edit_kind": "SET",
      "object_id": "stones",
      "property": "restitution",
      "outcome_type": "restitution_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "restitution (stones)": {
          "from": 0.0,
          "to": 0.95
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Pair restitution raised from perfectly inelastic to near-elastic. The symmetric collision now rebounds cleanly: stones bounce apart and end the clip at +/-0.95 m (baseline +/-0.32) still drifting away from centre.",
      "ground_truth": "scenes/curling_collision/cases/edit_bouncy_stones/ground_truth_transforms.json",
      "thumbnail": "thumbnails/curling_collision/edit_bouncy_stones.jpg"
    },
    {
      "global_id": "curling_collision/edit_add_stone_before_red",
      "scene": "curling_collision",
      "case_id": "edit_add_stone_before_red",
      "source_case_id": "curling_collision_baseline",
      "source_video": "scenes/curling_collision/cases/curling_collision_baseline/video.mp4",
      "edited_video": "scenes/curling_collision/cases/edit_add_stone_before_red/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,在红色冰壶和黄色冰壶的连线上、靠近红色冰壶的地方,放一个蓝色冰壶。",
          "en": "From the start of the clip, place the blue stone on the line between the red stone and the yellow stone, closer to the red stone."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,在红色冰壶和黄色冰壶连线的四等分点上放一个蓝色冰壶,取靠近红色冰壶的那个。",
          "en": "From frame 1 onwards, place the blue stone on the line between the red stone and the yellow stone, one quarter of the way from the red stone to the yellow stone."
        }
      },
      "edit_dsl": "ADD blue_stone BETWEEN red_stone AND yellow_stone AT 1/4 FROM red_stone",
      "edit_kind": "ADD",
      "object_id": "blue_stone",
      "property": null,
      "outcome_type": "object_added",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "blue_stone": {
          "from": "absent",
          "to": "present",
          "position": {
            "on_line_between": [
              "red_stone",
              "yellow_stone"
            ],
            "at": "1/4",
            "measured_from": "red_stone",
            "fraction_from_endpoint_a": 0.25,
            "resolved_location": [
              -1.25,
              0.0,
              0.057
            ],
            "endpoint_locations": [
              [
                -2.5,
                0.0,
                0.057
              ],
              [
                2.5,
                0.0,
                0.057
              ]
            ]
          }
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "A blue stone set down at the quarter point of the red-to-yellow line nearest the red throw, 1.25 m in front of it. Red closes that gap and sticks to it -- restitution is 0 on this ice -- stopping after 1.76 m against the baseline's 2.08 m. Blue is driven 0.81 m down the sheet into the oncoming yellow, and yellow is the stone that ends up past centre on red's side, at x=-0.10 after 2.60 m of travel.",
      "ground_truth": "scenes/curling_collision/cases/edit_add_stone_before_red/ground_truth_transforms.json",
      "thumbnail": "thumbnails/curling_collision/edit_add_stone_before_red.jpg"
    },
    {
      "global_id": "curling_collision/edit_add_stone_centre",
      "scene": "curling_collision",
      "case_id": "edit_add_stone_centre",
      "source_case_id": "curling_collision_baseline",
      "source_video": "scenes/curling_collision/cases/curling_collision_baseline/video.mp4",
      "edited_video": "scenes/curling_collision/cases/edit_add_stone_centre/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,在红色冰壶和黄色冰壶的连线上、大致中间的位置,放一个蓝色冰壶。",
          "en": "From the start of the clip, place the blue stone on the line between the red stone and the yellow stone, about midway between them."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,在红色冰壶和黄色冰壶连线的中点放一个蓝色冰壶。",
          "en": "From frame 1 onwards, place the blue stone at the midpoint of the line between the red stone and the yellow stone."
        }
      },
      "edit_dsl": "ADD blue_stone BETWEEN red_stone AND yellow_stone AT MIDPOINT",
      "edit_kind": "ADD",
      "object_id": "blue_stone",
      "property": null,
      "outcome_type": "object_added",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "blue_stone": {
          "from": "absent",
          "to": "present",
          "position": {
            "on_line_between": [
              "red_stone",
              "yellow_stone"
            ],
            "at": "midpoint",
            "measured_from": null,
            "fraction_from_endpoint_a": 0.5,
            "resolved_location": [
              0.0,
              0.0,
              0.057
            ],
            "endpoint_locations": [
              [
                -2.5,
                0.0,
                0.057
              ],
              [
                2.5,
                0.0,
                0.057
              ]
            ]
          }
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "A blue stone set down at the midpoint of the line between the two throws, in the gap they close in the baseline without quite touching. Both arrive on it and it is pinned between them: it shifts 13 mm and stops. Red and yellow are each stopped short of where they got to on their own -- x=-0.61 and x=+0.55 against the baseline's -0.42 and +0.42 -- because the stone between them takes up the gap they used to close.",
      "ground_truth": "scenes/curling_collision/cases/edit_add_stone_centre/ground_truth_transforms.json",
      "thumbnail": "thumbnails/curling_collision/edit_add_stone_centre.jpg"
    },
    {
      "global_id": "curling_collision/edit_add_stone_before_yellow",
      "scene": "curling_collision",
      "case_id": "edit_add_stone_before_yellow",
      "source_case_id": "curling_collision_baseline",
      "source_video": "scenes/curling_collision/cases/curling_collision_baseline/video.mp4",
      "edited_video": "scenes/curling_collision/cases/edit_add_stone_before_yellow/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,在红色冰壶和黄色冰壶的连线上、靠近黄色冰壶的地方,放一个蓝色冰壶。",
          "en": "From the start of the clip, place the blue stone on the line between the red stone and the yellow stone, closer to the yellow stone."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,在红色冰壶和黄色冰壶连线的四等分点上放一个蓝色冰壶,取靠近黄色冰壶的那个。",
          "en": "From frame 1 onwards, place the blue stone on the line between the red stone and the yellow stone, one quarter of the way from the yellow stone to the red stone."
        }
      },
      "edit_dsl": "ADD blue_stone BETWEEN red_stone AND yellow_stone AT 1/4 FROM yellow_stone",
      "edit_kind": "ADD",
      "object_id": "blue_stone",
      "property": null,
      "outcome_type": "object_added",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "blue_stone": {
          "from": "absent",
          "to": "present",
          "position": {
            "on_line_between": [
              "red_stone",
              "yellow_stone"
            ],
            "at": "1/4",
            "measured_from": "yellow_stone",
            "fraction_from_endpoint_a": 0.75,
            "resolved_location": [
              1.25,
              0.0,
              0.057
            ],
            "endpoint_locations": [
              [
                -2.5,
                0.0,
                0.057
              ],
              [
                2.5,
                0.0,
                0.057
              ]
            ]
          }
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "The mirror of edit_add_stone_before_red, measured from the yellow throw instead. Yellow sticks to the blue stone after 1.78 m, blue is driven 0.83 m into the oncoming red, and red is the one that carries through: it travels 2.63 m and finishes past centre on yellow's side at x=+0.13. Same division point in the prompt, opposite end of the sheet.",
      "ground_truth": "scenes/curling_collision/cases/edit_add_stone_before_yellow/ground_truth_transforms.json",
      "thumbnail": "thumbnails/curling_collision/edit_add_stone_before_yellow.jpg"
    },
    {
      "global_id": "dining_chain/edit_heavy_can",
      "scene": "dining_chain",
      "case_id": "edit_heavy_can",
      "source_case_id": "dining_chain_baseline",
      "source_video": "scenes/dining_chain/cases/dining_chain_baseline/video.mp4",
      "edited_video": "scenes/dining_chain/cases/edit_heavy_can/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把可乐罐的质量调大一些。",
          "en": "From the start of the clip, increase the cola can's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把可乐罐的质量增加到原来的 4 倍。",
          "en": "From frame 1 onwards, increase the cola can's mass to 4 times its original value."
        }
      },
      "edit_dsl": "SET can.mass TIMES 4",
      "edit_kind": "SET",
      "object_id": "can",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (can)": {
          "from": 0.36,
          "to": 1.44
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "The pushed can made 4x heavier. It carries so much more momentum through both handoffs that the whole chain runs about twice as far as the baseline -- can 2.76 m, cup 2.36 m, milk 1.98 m -- and everything ends bunched together past the middle of the table rather than strung out where each impact happened.",
      "ground_truth": "scenes/dining_chain/cases/edit_heavy_can/ground_truth_transforms.json",
      "thumbnail": "thumbnails/dining_chain/edit_heavy_can.jpg"
    },
    {
      "global_id": "dining_chain/edit_heavy_cup",
      "scene": "dining_chain",
      "case_id": "edit_heavy_cup",
      "source_case_id": "dining_chain_baseline",
      "source_video": "scenes/dining_chain/cases/dining_chain_baseline/video.mp4",
      "edited_video": "scenes/dining_chain/cases/edit_heavy_cup/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把汽水杯的质量调大一些。",
          "en": "From the start of the clip, increase the soda cup's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把汽水杯的质量增加到原来的 5 倍。",
          "en": "From frame 1 onwards, increase the soda cup's mass to 5 times its original value."
        }
      },
      "edit_dsl": "SET cup.mass TIMES 5",
      "edit_kind": "SET",
      "object_id": "cup",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (cup)": {
          "from": 0.3,
          "to": 1.5
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Middle cup made 5x heavier. The can hits it and rebounds instead of driving on: the can only slides 0.58 m (down from 1.31 m) and the cup barely creeps forward at 0.21 m. That's not enough to cover the 0.5 m gap to the milk, so the second handoff never happens -- the carton stays exactly where it started.",
      "ground_truth": "scenes/dining_chain/cases/edit_heavy_cup/ground_truth_transforms.json",
      "thumbnail": "thumbnails/dining_chain/edit_heavy_cup.jpg"
    },
    {
      "global_id": "dining_chain/edit_heavy_milk",
      "scene": "dining_chain",
      "case_id": "edit_heavy_milk",
      "source_case_id": "dining_chain_baseline",
      "source_video": "scenes/dining_chain/cases/dining_chain_baseline/video.mp4",
      "edited_video": "scenes/dining_chain/cases/edit_heavy_milk/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把牛奶盒的质量调大一些。",
          "en": "From the start of the clip, increase the milk carton's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把牛奶盒的质量增加到原来的 5 倍。",
          "en": "From frame 1 onwards, increase the milk carton's mass to 5 times its original value."
        }
      },
      "edit_dsl": "SET milk.mass TIMES 5",
      "edit_kind": "SET",
      "object_id": "milk",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (milk)": {
          "from": 0.35,
          "to": 1.75
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Last-link carton made 5x heavier. The first handoff is basically intact -- can 0.92 m, cup 0.51 m -- and the cup does reach the carton, but the impact is against an object massive enough that the carton only nudges 9 cm before stopping. The chain fails at the last link rather than the middle one.",
      "ground_truth": "scenes/dining_chain/cases/edit_heavy_milk/ground_truth_transforms.json",
      "thumbnail": "thumbnails/dining_chain/edit_heavy_milk.jpg"
    },
    {
      "global_id": "dining_chain/edit_soft_push",
      "scene": "dining_chain",
      "case_id": "edit_soft_push",
      "source_case_id": "dining_chain_baseline",
      "source_video": "scenes/dining_chain/cases/dining_chain_baseline/video.mp4",
      "edited_video": "scenes/dining_chain/cases/edit_soft_push/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把可乐罐的初速度大小调小一些。",
          "en": "From the start of the clip, decrease the cola can's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把可乐罐的初速度大小减少到原来的 0.5 倍。",
          "en": "From frame 1 onwards, reduce the cola can's initial speed to 0.5 times its original value."
        }
      },
      "edit_dsl": "SET can.initial_velocity TIMES 0.5",
      "edit_kind": "SET",
      "object_id": "can",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (can)": {
          "from": 3.3,
          "to": 1.65
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Push cut in half. The can still reaches the cup and shoves it, but the cup only slides 0.31 m -- 0.19 m short of the milk -- so the chain dies one link early for lack of speed rather than for any change downstream. The carton never moves, where the baseline carries it 0.48 m.",
      "ground_truth": "scenes/dining_chain/cases/edit_soft_push/ground_truth_transforms.json",
      "thumbnail": "thumbnails/dining_chain/edit_soft_push.jpg"
    },
    {
      "global_id": "dining_chain/edit_gentle_push",
      "scene": "dining_chain",
      "case_id": "edit_gentle_push",
      "source_case_id": "dining_chain_baseline",
      "source_video": "scenes/dining_chain/cases/dining_chain_baseline/video.mp4",
      "edited_video": "scenes/dining_chain/cases/edit_gentle_push/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把可乐罐的初速度大小调小一些。",
          "en": "From the start of the clip, decrease the cola can's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把可乐罐的初速度大小减少到原来的 0.25 倍。",
          "en": "From frame 1 onwards, reduce the cola can's initial speed to 0.25 times its original value."
        }
      },
      "edit_dsl": "SET can.initial_velocity TIMES 0.25",
      "edit_kind": "SET",
      "object_id": "can",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (can)": {
          "from": 3.3,
          "to": 0.825
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Too gentle a push. The can slides only 0.37 m, short of the 0.50 m to the cup, so no collision happens at all. The cup and the milk carton both stay exactly where they started, against the baseline's 0.91 m and 0.48 m.",
      "ground_truth": "scenes/dining_chain/cases/edit_gentle_push/ground_truth_transforms.json",
      "thumbnail": "thumbnails/dining_chain/edit_gentle_push.jpg"
    },
    {
      "global_id": "dining_chain/edit_remove_cup",
      "scene": "dining_chain",
      "case_id": "edit_remove_cup",
      "source_case_id": "dining_chain_baseline",
      "source_video": "scenes/dining_chain/cases/dining_chain_baseline/video.mp4",
      "edited_video": "scenes/dining_chain/cases/edit_remove_cup/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把汽水杯从场景中删除。",
          "en": "From the start of the clip, remove the soda cup from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把汽水杯从场景中删除。",
          "en": "From frame 1 onwards, remove the soda cup from the scene."
        }
      },
      "edit_dsl": "DELETE cup",
      "edit_kind": "DELETE",
      "object_id": "cup",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "cup": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Middle cup removed. The can coasts unobstructed through the empty gap and strikes the milk carton directly -- one handoff instead of two, and the carton takes 1.39 m of run instead of the baseline's 0.48 m because none of the push was spent on the cup.",
      "ground_truth": "scenes/dining_chain/cases/edit_remove_cup/ground_truth_transforms.json",
      "thumbnail": "thumbnails/dining_chain/edit_remove_cup.jpg"
    },
    {
      "global_id": "dining_chain/edit_remove_milk",
      "scene": "dining_chain",
      "case_id": "edit_remove_milk",
      "source_case_id": "dining_chain_baseline",
      "source_video": "scenes/dining_chain/cases/dining_chain_baseline/video.mp4",
      "edited_video": "scenes/dining_chain/cases/edit_remove_milk/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把牛奶盒从场景中删除。",
          "en": "From the start of the clip, remove the milk carton from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把牛奶盒从场景中删除。",
          "en": "From frame 1 onwards, remove the milk carton from the scene."
        }
      },
      "edit_dsl": "DELETE milk",
      "edit_kind": "DELETE",
      "object_id": "milk",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "milk": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Last-link carton removed. The first handoff is unchanged -- can 1.80 m, cup 1.58 m -- but the cup then coasts through the empty slot at the end of the chain instead of stopping on the carton, and ends much further along the table than in the baseline.",
      "ground_truth": "scenes/dining_chain/cases/edit_remove_milk/ground_truth_transforms.json",
      "thumbnail": "thumbnails/dining_chain/edit_remove_milk.jpg"
    },
    {
      "global_id": "dining_chain/edit_remove_cup_mid_slide",
      "scene": "dining_chain",
      "case_id": "edit_remove_cup_mid_slide",
      "source_case_id": "dining_chain_baseline",
      "source_video": "scenes/dining_chain/cases/dining_chain_baseline/video.mp4",
      "edited_video": "scenes/dining_chain/cases/edit_remove_cup_mid_slide/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "在视频前段,把汽水杯从场景中删除。",
          "en": "Early in the clip, remove the soda cup from the scene."
        },
        "quantitative": {
          "zh": "从第 10 帧开始,把汽水杯从场景中删除。",
          "en": "From frame 10 onwards, remove the soda cup from the scene."
        }
      },
      "edit_dsl": "DELETE cup AT FRAME 10",
      "edit_kind": "DELETE",
      "object_id": "cup",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 10,
      "timing": "partway",
      "physics_diff": {
        "cup": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 10,
          "total_frames": 96,
          "unedited_frames": [
            1,
            9
          ]
        }
      },
      "edit_summary": "Cup removed at frame 10, five frames after the can runs into it and one before it would have reached the milk. Frames 1-9 are the source video frame for frame, first impact included: the can is down from 3.3 m/s to about 1.4, and the cup is 0.4 m along when it disappears. The can then reaches the milk itself, but with what little speed it has left -- the milk is nudged to y=+0.03 instead of the source's +0.28. The whole-clip version of the same delete is a different video again: with no cup to hit, the can arrives at the milk at full speed and drives it out to y=+1.19.",
      "ground_truth": "scenes/dining_chain/cases/edit_remove_cup_mid_slide/ground_truth_transforms.json",
      "thumbnail": "thumbnails/dining_chain/edit_remove_cup_mid_slide.jpg"
    },
    {
      "global_id": "domino_chain/edit_heavy_domino_2",
      "scene": "domino_chain",
      "case_id": "edit_heavy_domino_2",
      "source_case_id": "domino_chain_baseline",
      "source_video": "scenes/domino_chain/cases/domino_chain_baseline/video.mp4",
      "edited_video": "scenes/domino_chain/cases/edit_heavy_domino_2/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把第 2 张骨牌的质量调大一些。",
          "en": "From the start of the clip, increase the second domino's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把第 2 张骨牌的质量增加到原来的 10 倍。",
          "en": "From frame 1 onwards, increase the second domino's mass to 10 times its original value."
        }
      },
      "edit_dsl": "SET domino_2.mass TIMES 10",
      "edit_kind": "SET",
      "object_id": "domino_2",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (domino_2)": {
          "from": 0.12,
          "to": 1.2
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Second tile made 10x heavier. Tile 1 falls onto it as usual, but the heavier tile only tilts 1 degree before absorbing the impact and stops the chain dead -- tiles 3 and 4 never move. In the baseline all four topple; here toppled=0/4.",
      "ground_truth": "scenes/domino_chain/cases/edit_heavy_domino_2/ground_truth_transforms.json",
      "thumbnail": "thumbnails/domino_chain/edit_heavy_domino_2.jpg"
    },
    {
      "global_id": "domino_chain/edit_heavy_domino_3",
      "scene": "domino_chain",
      "case_id": "edit_heavy_domino_3",
      "source_case_id": "domino_chain_baseline",
      "source_video": "scenes/domino_chain/cases/domino_chain_baseline/video.mp4",
      "edited_video": "scenes/domino_chain/cases/edit_heavy_domino_3/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把第 3 张骨牌的质量调大一些。",
          "en": "From the start of the clip, increase the third domino's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把第 3 张骨牌的质量增加到原来的 10 倍。",
          "en": "From frame 1 onwards, increase the third domino's mass to 10 times its original value."
        }
      },
      "edit_dsl": "SET domino_3.mass TIMES 10",
      "edit_kind": "SET",
      "object_id": "domino_3",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (domino_3)": {
          "from": 0.12,
          "to": 1.2
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Third tile made 10x heavier. The first two tiles topple normally (tile 1 to 75 degrees, tile 2 to 29 degrees), but the impact on the heavier tile 3 only tilts it 2 degrees -- the chain breaks one link further along than the heavy-2 edit does, and tile 4 still never falls.",
      "ground_truth": "scenes/domino_chain/cases/edit_heavy_domino_3/ground_truth_transforms.json",
      "thumbnail": "thumbnails/domino_chain/edit_heavy_domino_3.jpg"
    },
    {
      "global_id": "domino_chain/edit_remove_domino_1",
      "scene": "domino_chain",
      "case_id": "edit_remove_domino_1",
      "source_case_id": "domino_chain_baseline",
      "source_video": "scenes/domino_chain/cases/domino_chain_baseline/video.mp4",
      "edited_video": "scenes/domino_chain/cases/edit_remove_domino_1/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把第 1 张骨牌从场景中删除。",
          "en": "From the start of the clip, remove the first domino from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把第 1 张骨牌从场景中删除。",
          "en": "From frame 1 onwards, remove the first domino from the scene."
        }
      },
      "edit_dsl": "DELETE domino_1",
      "edit_kind": "DELETE",
      "object_id": "domino_1",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "domino_1": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "First tile removed -- and with it the only tile that starts pre-tilted past its critical angle. No push, no first fall, and no chain: tiles 2, 3, and 4 all stand undisturbed for the whole shot. Toppled=0/4.",
      "ground_truth": "scenes/domino_chain/cases/edit_remove_domino_1/ground_truth_transforms.json",
      "thumbnail": "thumbnails/domino_chain/edit_remove_domino_1.jpg"
    },
    {
      "global_id": "domino_chain/edit_remove_domino_1_mid_fall",
      "scene": "domino_chain",
      "case_id": "edit_remove_domino_1_mid_fall",
      "source_case_id": "domino_chain_baseline",
      "source_video": "scenes/domino_chain/cases/domino_chain_baseline/video.mp4",
      "edited_video": "scenes/domino_chain/cases/edit_remove_domino_1_mid_fall/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "在视频前段,把第 1 张骨牌从场景中删除。",
          "en": "Early in the clip, remove the first domino from the scene."
        },
        "quantitative": {
          "zh": "从第 24 帧开始,把第 1 张骨牌从场景中删除。",
          "en": "From frame 24 onwards, remove the first domino from the scene."
        }
      },
      "edit_dsl": "DELETE domino_1 AT FRAME 24",
      "edit_kind": "DELETE",
      "object_id": "domino_1",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 24,
      "timing": "partway",
      "physics_diff": {
        "domino_1": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 24,
          "total_frames": 96,
          "unedited_frames": [
            1,
            23
          ]
        }
      },
      "edit_summary": "First tile removed at frame 24 of 96, while it is still falling. Frames 1-23 are the source video frame for frame: tile 1 tips from its 12 degree start and reaches 38 degrees, having met tile 2 at frame 21 and started it moving (tile 2 is 5 degrees over at frame 24). Tile 1 then vanishes mid-fall, leaning but nowhere near down, and the rest of the row carries on under the momentum it already had: tiles 2, 3 and 4 all still topple, but each crosses 45 degrees six to eight frames later than in the source (frames 43, 51, 55 against 37, 43, 47) and the row settles around frame 60 instead of frame 52. The end state matches the baseline -- 76, 76 and flat at 90 degrees, within 0.2 degrees and 4 cm -- so what separates this from the source is the missing tile plus a visibly slower cascade. Toppled=3/4. The whole-clip version of the same delete (edit_remove_domino_1) is a different video again: with no pre-tilted tile to start it, nothing in the row ever moves.",
      "ground_truth": "scenes/domino_chain/cases/edit_remove_domino_1_mid_fall/ground_truth_transforms.json",
      "thumbnail": "thumbnails/domino_chain/edit_remove_domino_1_mid_fall.jpg"
    },
    {
      "global_id": "domino_chain/edit_remove_domino_2",
      "scene": "domino_chain",
      "case_id": "edit_remove_domino_2",
      "source_case_id": "domino_chain_baseline",
      "source_video": "scenes/domino_chain/cases/domino_chain_baseline/video.mp4",
      "edited_video": "scenes/domino_chain/cases/edit_remove_domino_2/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把第 2 张骨牌从场景中删除。",
          "en": "From the start of the clip, remove the second domino from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把第 2 张骨牌从场景中删除。",
          "en": "From frame 1 onwards, remove the second domino from the scene."
        }
      },
      "edit_dsl": "DELETE domino_2",
      "edit_kind": "DELETE",
      "object_id": "domino_2",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "domino_2": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Second tile removed. Tile 1 topples the full 90 degrees and lands flat -- but into empty space where tile 2 should have been, so there is nothing to pass the impulse to. Tiles 3 and 4 stand undisturbed. Toppled=1/4.",
      "ground_truth": "scenes/domino_chain/cases/edit_remove_domino_2/ground_truth_transforms.json",
      "thumbnail": "thumbnails/domino_chain/edit_remove_domino_2.jpg"
    },
    {
      "global_id": "domino_chain/edit_remove_domino_3",
      "scene": "domino_chain",
      "case_id": "edit_remove_domino_3",
      "source_case_id": "domino_chain_baseline",
      "source_video": "scenes/domino_chain/cases/domino_chain_baseline/video.mp4",
      "edited_video": "scenes/domino_chain/cases/edit_remove_domino_3/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把第 3 张骨牌从场景中删除。",
          "en": "From the start of the clip, remove the third domino from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把第 3 张骨牌从场景中删除。",
          "en": "From frame 1 onwards, remove the third domino from the scene."
        }
      },
      "edit_dsl": "DELETE domino_3",
      "edit_kind": "DELETE",
      "object_id": "domino_3",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "domino_3": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Third tile removed. Tiles 1 and 2 still fall in sequence, tile 2 lying flat past 90 degrees, but the 1.6 m gap to tile 4 is more than the tile's 1.30 m height can reach -- so the chain dies at the empty middle slot. Tile 4 stands undisturbed. Toppled=2/4.",
      "ground_truth": "scenes/domino_chain/cases/edit_remove_domino_3/ground_truth_transforms.json",
      "thumbnail": "thumbnails/domino_chain/edit_remove_domino_3.jpg"
    },
    {
      "global_id": "domino_chain/edit_remove_domino_4",
      "scene": "domino_chain",
      "case_id": "edit_remove_domino_4",
      "source_case_id": "domino_chain_baseline",
      "source_video": "scenes/domino_chain/cases/domino_chain_baseline/video.mp4",
      "edited_video": "scenes/domino_chain/cases/edit_remove_domino_4/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把第 4 张骨牌从场景中删除。",
          "en": "From the start of the clip, remove the fourth domino from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把第 4 张骨牌从场景中删除。",
          "en": "From frame 1 onwards, remove the fourth domino from the scene."
        }
      },
      "edit_dsl": "DELETE domino_4",
      "edit_kind": "DELETE",
      "object_id": "domino_4",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "domino_4": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Last tile removed. The rest of the cascade is unchanged -- tiles 1, 2, and 3 all topple in sequence -- but there is nothing at the end for tile 3 to knock over, so it lies flat into an empty slot. Toppled=3/4.",
      "ground_truth": "scenes/domino_chain/cases/edit_remove_domino_4/ground_truth_transforms.json",
      "thumbnail": "thumbnails/domino_chain/edit_remove_domino_4.jpg"
    },
    {
      "global_id": "mahjong_dice/edit_dead_red_die",
      "scene": "mahjong_dice",
      "case_id": "edit_dead_red_die",
      "source_case_id": "mahjong_dice_baseline",
      "source_video": "scenes/mahjong_dice/cases/mahjong_dice_baseline/video.mp4",
      "edited_video": "scenes/mahjong_dice/cases/edit_dead_red_die/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把红色骰子的恢复系数调小一些。",
          "en": "From the start of the clip, decrease the red die's restitution."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把红色骰子的恢复系数减少到原来的 0.05 倍。",
          "en": "From frame 1 onwards, reduce the red die's restitution to 0.05 times its original value."
        }
      },
      "edit_dsl": "SET red_die.restitution TIMES 0.05",
      "edit_kind": "SET",
      "object_id": "red_die",
      "property": "restitution",
      "outcome_type": "restitution_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "restitution (red_die)": {
          "from": 0.72,
          "to": 0.036
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Red die's restitution killed. Its first tray contact goes almost fully inelastic: no bounces at all against the baseline's three, and a 0.60 m path -- a straight drop and a stop -- instead of 1.04 m. The white die is untouched.",
      "ground_truth": "scenes/mahjong_dice/cases/edit_dead_red_die/ground_truth_transforms.json",
      "thumbnail": "thumbnails/mahjong_dice/edit_dead_red_die.jpg"
    },
    {
      "global_id": "mahjong_dice/edit_bouncy_white_die",
      "scene": "mahjong_dice",
      "case_id": "edit_bouncy_white_die",
      "source_case_id": "mahjong_dice_baseline",
      "source_video": "scenes/mahjong_dice/cases/mahjong_dice_baseline/video.mp4",
      "edited_video": "scenes/mahjong_dice/cases/edit_bouncy_white_die/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把白色骰子的恢复系数调大一些。",
          "en": "From the start of the clip, increase the white die's restitution."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把白色骰子的恢复系数增加到原来的 1.3 倍。",
          "en": "From frame 1 onwards, increase the white die's restitution to 1.3 times its original value."
        }
      },
      "edit_dsl": "SET white_die.restitution TIMES 1.3",
      "edit_kind": "SET",
      "object_id": "white_die",
      "property": "restitution",
      "outcome_type": "restitution_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "restitution (white_die)": {
          "from": 0.72,
          "to": 0.936
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "White die made near-perfectly bouncy. It keeps six bounces instead of four and covers a 1.86 m path in the tray against the baseline's 1.13 m before settling. The red die is untouched and lands exactly as it does in the source.",
      "ground_truth": "scenes/mahjong_dice/cases/edit_bouncy_white_die/ground_truth_transforms.json",
      "thumbnail": "thumbnails/mahjong_dice/edit_bouncy_white_die.jpg"
    },
    {
      "global_id": "mahjong_dice/edit_hard_throw_red_die",
      "scene": "mahjong_dice",
      "case_id": "edit_hard_throw_red_die",
      "source_case_id": "mahjong_dice_baseline",
      "source_video": "scenes/mahjong_dice/cases/mahjong_dice_baseline/video.mp4",
      "edited_video": "scenes/mahjong_dice/cases/edit_hard_throw_red_die/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把红色骰子的初速度大小调大一些。",
          "en": "From the start of the clip, increase the red die's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把红色骰子的初速度大小增加到原来的 3 倍。",
          "en": "From frame 1 onwards, increase the red die's initial speed to 3 times its original value."
        }
      },
      "edit_dsl": "SET red_die.initial_velocity TIMES 3",
      "edit_kind": "SET",
      "object_id": "red_die",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (red_die)": {
          "from": 1.5,
          "to": 4.5
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Red die thrown three times harder. It hits the tray at 5.27 m/s instead of 3.50, and the extra energy shows in the scatter: four bounces instead of three, and a 2.16 m path against the baseline's 1.04 m. The white die is untouched.",
      "ground_truth": "scenes/mahjong_dice/cases/edit_hard_throw_red_die/ground_truth_transforms.json",
      "thumbnail": "thumbnails/mahjong_dice/edit_hard_throw_red_die.jpg"
    },
    {
      "global_id": "mahjong_dice/edit_hard_throw_white_die",
      "scene": "mahjong_dice",
      "case_id": "edit_hard_throw_white_die",
      "source_case_id": "mahjong_dice_baseline",
      "source_video": "scenes/mahjong_dice/cases/mahjong_dice_baseline/video.mp4",
      "edited_video": "scenes/mahjong_dice/cases/edit_hard_throw_white_die/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把白色骰子的初速度大小调大一些。",
          "en": "From the start of the clip, increase the white die's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把白色骰子的初速度大小增加到原来的 4 倍。",
          "en": "From frame 1 onwards, increase the white die's initial speed to 4 times its original value."
        }
      },
      "edit_dsl": "SET white_die.initial_velocity TIMES 4",
      "edit_kind": "SET",
      "object_id": "white_die",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (white_die)": {
          "from": 0.8,
          "to": 3.2
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "White die thrown four times harder. It reaches the tray at 4.38 m/s instead of 3.61 and scatters further -- a 1.50 m path against the baseline's 1.13 m -- though it still settles in four bounces. The red die is untouched.",
      "ground_truth": "scenes/mahjong_dice/cases/edit_hard_throw_white_die/ground_truth_transforms.json",
      "thumbnail": "thumbnails/mahjong_dice/edit_hard_throw_white_die.jpg"
    },
    {
      "global_id": "mahjong_dice/edit_remove_red_die",
      "scene": "mahjong_dice",
      "case_id": "edit_remove_red_die",
      "source_case_id": "mahjong_dice_baseline",
      "source_video": "scenes/mahjong_dice/cases/mahjong_dice_baseline/video.mp4",
      "edited_video": "scenes/mahjong_dice/cases/edit_remove_red_die/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把红色骰子从场景中删除。",
          "en": "From the start of the clip, remove the red die from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把红色骰子从场景中删除。",
          "en": "From frame 1 onwards, remove the red die from the scene."
        }
      },
      "edit_dsl": "DELETE red_die",
      "edit_kind": "DELETE",
      "object_id": "red_die",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "red_die": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Red die removed. Only the white die falls; its trajectory is identical to the baseline's (5 bounces, 14 cm peak), but the tray ends with a single white die in it instead of a red-white pair.",
      "ground_truth": "scenes/mahjong_dice/cases/edit_remove_red_die/ground_truth_transforms.json",
      "thumbnail": "thumbnails/mahjong_dice/edit_remove_red_die.jpg"
    },
    {
      "global_id": "mahjong_dice/edit_remove_white_die",
      "scene": "mahjong_dice",
      "case_id": "edit_remove_white_die",
      "source_case_id": "mahjong_dice_baseline",
      "source_video": "scenes/mahjong_dice/cases/mahjong_dice_baseline/video.mp4",
      "edited_video": "scenes/mahjong_dice/cases/edit_remove_white_die/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把白色骰子从场景中删除。",
          "en": "From the start of the clip, remove the white die from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把白色骰子从场景中删除。",
          "en": "From frame 1 onwards, remove the white die from the scene."
        }
      },
      "edit_dsl": "DELETE white_die",
      "edit_kind": "DELETE",
      "object_id": "white_die",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "white_die": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "White die removed. Only the red die falls; its trajectory is identical to the baseline's (5 bounces, 15 cm peak), but the tray ends with a single red die in it instead of a red-white pair.",
      "ground_truth": "scenes/mahjong_dice/cases/edit_remove_white_die/ground_truth_transforms.json",
      "thumbnail": "thumbnails/mahjong_dice/edit_remove_white_die.jpg"
    },
    {
      "global_id": "picnic_apple_ball/edit_heavy_soccer_ball",
      "scene": "picnic_apple_ball",
      "case_id": "edit_heavy_soccer_ball",
      "source_case_id": "picnic_apple_ball_baseline",
      "source_video": "scenes/picnic_apple_ball/cases/picnic_apple_ball_baseline/video.mp4",
      "edited_video": "scenes/picnic_apple_ball/cases/edit_heavy_soccer_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把足球的质量调大一些。",
          "en": "From the start of the clip, increase the soccer ball's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把足球的质量增加到原来的 4 倍。",
          "en": "From frame 1 onwards, increase the soccer ball's mass to 4 times its original value."
        }
      },
      "edit_dsl": "SET soccer_ball.mass TIMES 4",
      "edit_kind": "SET",
      "object_id": "soccer_ball",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (soccer_ball)": {
          "from": 0.43,
          "to": 1.72
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Soccer ball made 4x heavier. The same apple impact now delivers a much smaller change of momentum, so the ball barely reacts: it rolls only 0.04 m before stopping instead of the baseline's 0.54 m.",
      "ground_truth": "scenes/picnic_apple_ball/cases/edit_heavy_soccer_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/picnic_apple_ball/edit_heavy_soccer_ball.jpg"
    },
    {
      "global_id": "picnic_apple_ball/edit_slick_soccer_ball",
      "scene": "picnic_apple_ball",
      "case_id": "edit_slick_soccer_ball",
      "source_case_id": "picnic_apple_ball_baseline",
      "source_video": "scenes/picnic_apple_ball/cases/picnic_apple_ball_baseline/video.mp4",
      "edited_video": "scenes/picnic_apple_ball/cases/edit_slick_soccer_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把足球的摩擦系数调小一些。",
          "en": "From the start of the clip, decrease the soccer ball's friction coefficient."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把足球的摩擦系数减少到原来的 0.4 倍。",
          "en": "From frame 1 onwards, reduce the soccer ball's friction coefficient to 0.4 times its original value."
        }
      },
      "edit_dsl": "SET soccer_ball.friction TIMES 0.4",
      "edit_kind": "SET",
      "object_id": "soccer_ball",
      "property": "friction",
      "outcome_type": "friction_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "friction (soccer_ball)": {
          "from": 0.25,
          "to": 0.1
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Soccer ball's friction cut 2.5x. Both the lateral coefficient and the rolling one scale together, so after the same apple impact the ball meets much less grip on the grass and rolls 1.25 m -- more than 2x the 0.54 m baseline -- before settling within the shot.",
      "ground_truth": "scenes/picnic_apple_ball/cases/edit_slick_soccer_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/picnic_apple_ball/edit_slick_soccer_ball.jpg"
    },
    {
      "global_id": "picnic_apple_ball/edit_grippy_soccer_ball",
      "scene": "picnic_apple_ball",
      "case_id": "edit_grippy_soccer_ball",
      "source_case_id": "picnic_apple_ball_baseline",
      "source_video": "scenes/picnic_apple_ball/cases/picnic_apple_ball_baseline/video.mp4",
      "edited_video": "scenes/picnic_apple_ball/cases/edit_grippy_soccer_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把足球的摩擦系数调大一些。",
          "en": "From the start of the clip, increase the soccer ball's friction coefficient."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把足球的摩擦系数增加到原来的 3 倍。",
          "en": "From frame 1 onwards, increase the soccer ball's friction coefficient to 3 times its original value."
        }
      },
      "edit_dsl": "SET soccer_ball.friction TIMES 3",
      "edit_kind": "SET",
      "object_id": "soccer_ball",
      "property": "friction",
      "outcome_type": "friction_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "friction (soccer_ball)": {
          "from": 0.25,
          "to": 0.75
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Soccer ball's friction tripled. The grass grips the ball hard enough to damp the roll almost immediately: it moves only 0.04 m before stopping, vs 0.54 m in the baseline. Different mechanism from the heavy-ball edit -- same visible outcome, but the ball here has normal inertia and just cannot overcome the friction.",
      "ground_truth": "scenes/picnic_apple_ball/cases/edit_grippy_soccer_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/picnic_apple_ball/edit_grippy_soccer_ball.jpg"
    },
    {
      "global_id": "picnic_apple_ball/edit_heavy_apple",
      "scene": "picnic_apple_ball",
      "case_id": "edit_heavy_apple",
      "source_case_id": "picnic_apple_ball_baseline",
      "source_video": "scenes/picnic_apple_ball/cases/picnic_apple_ball_baseline/video.mp4",
      "edited_video": "scenes/picnic_apple_ball/cases/edit_heavy_apple/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把苹果的质量调大一些。",
          "en": "From the start of the clip, increase the apple's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把苹果的质量增加到原来的 2 倍。",
          "en": "From frame 1 onwards, increase the apple's mass to 2 times its original value."
        }
      },
      "edit_dsl": "SET apple.mass TIMES 2",
      "edit_kind": "SET",
      "object_id": "apple",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (apple)": {
          "from": 0.15,
          "to": 0.3
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Apple made twice as heavy. The off-centre hit carries more momentum into the ball: it rolls 1.66 m, about three times the baseline's 0.54 m, and comes to rest before the shot ends. The apple itself is slowed by the exchange, covering 2.07 m against 2.37 m.",
      "ground_truth": "scenes/picnic_apple_ball/cases/edit_heavy_apple/ground_truth_transforms.json",
      "thumbnail": "thumbnails/picnic_apple_ball/edit_heavy_apple.jpg"
    },
    {
      "global_id": "picnic_apple_ball/edit_remove_apple",
      "scene": "picnic_apple_ball",
      "case_id": "edit_remove_apple",
      "source_case_id": "picnic_apple_ball_baseline",
      "source_video": "scenes/picnic_apple_ball/cases/picnic_apple_ball_baseline/video.mp4",
      "edited_video": "scenes/picnic_apple_ball/cases/edit_remove_apple/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把苹果从场景中删除。",
          "en": "From the start of the clip, remove the apple from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把苹果从场景中删除。",
          "en": "From frame 1 onwards, remove the apple from the scene."
        }
      },
      "edit_dsl": "DELETE apple",
      "edit_kind": "DELETE",
      "object_id": "apple",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "apple": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Apple removed. Nothing falls; the soccer ball sits undisturbed on the grass for the whole shot. Roll distance 0 m.",
      "ground_truth": "scenes/picnic_apple_ball/cases/edit_remove_apple/ground_truth_transforms.json",
      "thumbnail": "thumbnails/picnic_apple_ball/edit_remove_apple.jpg"
    },
    {
      "global_id": "picnic_apple_ball/edit_remove_soccer_ball",
      "scene": "picnic_apple_ball",
      "case_id": "edit_remove_soccer_ball",
      "source_case_id": "picnic_apple_ball_baseline",
      "source_video": "scenes/picnic_apple_ball/cases/picnic_apple_ball_baseline/video.mp4",
      "edited_video": "scenes/picnic_apple_ball/cases/edit_remove_soccer_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把足球从场景中删除。",
          "en": "From the start of the clip, remove the soccer ball from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把足球从场景中删除。",
          "en": "From frame 1 onwards, remove the soccer ball from the scene."
        }
      },
      "edit_dsl": "DELETE soccer_ball",
      "edit_kind": "DELETE",
      "object_id": "soccer_ball",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "soccer_ball": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Soccer ball removed. The apple falls the full 1.3 m from the branch and lands on the grass beside the picnic blanket instead of on top of a ball -- a single, isolated apple drop rather than an oblique hit and a roll.",
      "ground_truth": "scenes/picnic_apple_ball/cases/edit_remove_soccer_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/picnic_apple_ball/edit_remove_soccer_ball.jpg"
    },
    {
      "global_id": "picnic_apple_ball/edit_remove_apple_after_impact",
      "scene": "picnic_apple_ball",
      "case_id": "edit_remove_apple_after_impact",
      "source_case_id": "picnic_apple_ball_baseline",
      "source_video": "scenes/picnic_apple_ball/cases/picnic_apple_ball_baseline/video.mp4",
      "edited_video": "scenes/picnic_apple_ball/cases/edit_remove_apple_after_impact/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "在视频前段,把苹果从场景中删除。",
          "en": "Early in the clip, remove the apple from the scene."
        },
        "quantitative": {
          "zh": "从第 18 帧开始,把苹果从场景中删除。",
          "en": "From frame 18 onwards, remove the apple from the scene."
        }
      },
      "edit_dsl": "DELETE apple AT FRAME 18",
      "edit_kind": "DELETE",
      "object_id": "apple",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 18,
      "timing": "partway",
      "physics_diff": {
        "apple": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 18,
          "total_frames": 96,
          "unedited_frames": [
            1,
            17
          ]
        }
      },
      "edit_summary": "Apple removed at frame 18, four frames after it reaches the soccer ball at frame 14. Frames 1-17 are the source video frame for frame, impact included: the ball is knocked back to 0.64 m/s and the apple is 0.28 m past its start when it disappears. The ball rolls on to x=-0.54 exactly as in the source, with nothing left on the grass to follow it. The whole-clip version of the same delete is a different video again: with no apple to arrive, the ball never moves at all.",
      "ground_truth": "scenes/picnic_apple_ball/cases/edit_remove_apple_after_impact/ground_truth_transforms.json",
      "thumbnail": "thumbnails/picnic_apple_ball/edit_remove_apple_after_impact.jpg"
    },
    {
      "global_id": "pool_collision/edit_heavy_cue_ball",
      "scene": "pool_collision",
      "case_id": "edit_heavy_cue_ball",
      "source_case_id": "pool_collision_baseline",
      "source_video": "scenes/pool_collision/cases/pool_collision_baseline/video.mp4",
      "edited_video": "scenes/pool_collision/cases/edit_heavy_cue_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把母球的质量调大一些。",
          "en": "From the start of the clip, increase the cue ball's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把母球的质量增加到原来的 5 倍。",
          "en": "From frame 1 onwards, increase the cue ball's mass to 5 times its original value."
        }
      },
      "edit_dsl": "SET cue_ball.mass TIMES 5",
      "edit_kind": "SET",
      "object_id": "cue_ball",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (cue_ball)": {
          "from": 0.17,
          "to": 0.85
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Cue ball made 5x heavier. The head-on hit no longer swaps velocities cleanly: the cue drives on behind the target rather than stopping dead, keeping 0.27 m/s while the target leaves at 0.48 m/s. Both balls end farther down the table than in the baseline (cue displacement 1.05 m, target 0.74 m vs 0.50 m and 0.62 m at baseline).",
      "ground_truth": "scenes/pool_collision/cases/edit_heavy_cue_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/pool_collision/edit_heavy_cue_ball.jpg"
    },
    {
      "global_id": "pool_collision/edit_heavy_target_ball",
      "scene": "pool_collision",
      "case_id": "edit_heavy_target_ball",
      "source_case_id": "pool_collision_baseline",
      "source_video": "scenes/pool_collision/cases/pool_collision_baseline/video.mp4",
      "edited_video": "scenes/pool_collision/cases/edit_heavy_target_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把目标球的质量调大一些。",
          "en": "From the start of the clip, increase the target ball's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把目标球的质量增加到原来的 10 倍。",
          "en": "From frame 1 onwards, increase the target ball's mass to 10 times its original value."
        }
      },
      "edit_dsl": "SET target_ball.mass TIMES 10",
      "edit_kind": "SET",
      "object_id": "target_ball",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (target_ball)": {
          "from": 0.17,
          "to": 1.7
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Target ball made 10x heavier. The cue bounces back off it and the target barely reacts: cue displacement 0.26 m (much of that backwards after the rebound), target displacement 0.11 m. Cue keeps 0.32 m/s after the collision; the target ends at rest.",
      "ground_truth": "scenes/pool_collision/cases/edit_heavy_target_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/pool_collision/edit_heavy_target_ball.jpg"
    },
    {
      "global_id": "pool_collision/edit_hard_break",
      "scene": "pool_collision",
      "case_id": "edit_hard_break",
      "source_case_id": "pool_collision_baseline",
      "source_video": "scenes/pool_collision/cases/pool_collision_baseline/video.mp4",
      "edited_video": "scenes/pool_collision/cases/edit_hard_break/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把母球的初速度大小调大一些。",
          "en": "From the start of the clip, increase the cue ball's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把母球的初速度大小增加到原来的 4 倍。",
          "en": "From frame 1 onwards, increase the cue ball's initial speed to 4 times its original value."
        }
      },
      "edit_dsl": "SET cue_ball.initial_velocity TIMES 4",
      "edit_kind": "SET",
      "object_id": "cue_ball",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (cue_ball)": {
          "from": 1.0,
          "to": 4.0
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Cue ball's break speed 4x faster (1.0 -> 4.0 m/s along the table). Contact happens by frame 4 instead of 13, and the target rockets away at 1.23 m/s -- more than 2.5x the baseline's post-collision target speed -- ending up 0.67 m down the table before the wall stops it.",
      "ground_truth": "scenes/pool_collision/cases/edit_hard_break/ground_truth_transforms.json",
      "thumbnail": "thumbnails/pool_collision/edit_hard_break.jpg"
    },
    {
      "global_id": "pool_collision/edit_grippy_cue_ball",
      "scene": "pool_collision",
      "case_id": "edit_grippy_cue_ball",
      "source_case_id": "pool_collision_baseline",
      "source_video": "scenes/pool_collision/cases/pool_collision_baseline/video.mp4",
      "edited_video": "scenes/pool_collision/cases/edit_grippy_cue_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把母球的摩擦系数调大一些。",
          "en": "From the start of the clip, increase the cue ball's friction coefficient."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把母球的摩擦系数增加到原来的 10 倍。",
          "en": "From frame 1 onwards, increase the cue ball's friction coefficient to 10 times its original value."
        }
      },
      "edit_dsl": "SET cue_ball.friction TIMES 10",
      "edit_kind": "SET",
      "object_id": "cue_ball",
      "property": "friction",
      "outcome_type": "friction_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "friction (cue_ball)": {
          "from": 0.15,
          "to": 1.5
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Cue ball's friction 10x -- both lateral and rolling coefficients scale together. The felt now drags the cue to a stop before it ever reaches the target: cue displacement 0.42 m (short of the 0.6 m gap), no contact, the target never moves.",
      "ground_truth": "scenes/pool_collision/cases/edit_grippy_cue_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/pool_collision/edit_grippy_cue_ball.jpg"
    },
    {
      "global_id": "pool_collision/edit_remove_cue_ball",
      "scene": "pool_collision",
      "case_id": "edit_remove_cue_ball",
      "source_case_id": "pool_collision_baseline",
      "source_video": "scenes/pool_collision/cases/pool_collision_baseline/video.mp4",
      "edited_video": "scenes/pool_collision/cases/edit_remove_cue_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把母球从场景中删除。",
          "en": "From the start of the clip, remove the cue ball from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把母球从场景中删除。",
          "en": "From frame 1 onwards, remove the cue ball from the scene."
        }
      },
      "edit_dsl": "DELETE cue_ball",
      "edit_kind": "DELETE",
      "object_id": "cue_ball",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "cue_ball": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Cue ball removed. Nothing strikes the target; it sits alone on the felt for the whole shot. No motion, no collision.",
      "ground_truth": "scenes/pool_collision/cases/edit_remove_cue_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/pool_collision/edit_remove_cue_ball.jpg"
    },
    {
      "global_id": "pool_collision/edit_add_ball_near_cue",
      "scene": "pool_collision",
      "case_id": "edit_add_ball_near_cue",
      "source_case_id": "pool_collision_baseline",
      "source_video": "scenes/pool_collision/cases/pool_collision_baseline/video.mp4",
      "edited_video": "scenes/pool_collision/cases/edit_add_ball_near_cue/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,在母球和目标球的连线上、靠近母球的地方,放一个黄色1号球。",
          "en": "From the start of the clip, place the yellow one-ball on the line between the cue ball and the target ball, closer to the cue ball."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,在母球和目标球连线的四等分点上放一个黄色1号球,取靠近母球的那个。",
          "en": "From frame 1 onwards, place the yellow one-ball on the line between the cue ball and the target ball, one quarter of the way from the cue ball to the target ball."
        }
      },
      "edit_dsl": "ADD yellow_ball BETWEEN cue_ball AND target_ball AT 1/4 FROM cue_ball",
      "edit_kind": "ADD",
      "object_id": "yellow_ball",
      "property": null,
      "outcome_type": "object_added",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "yellow_ball": {
          "from": "absent",
          "to": "present",
          "position": {
            "on_line_between": [
              "cue_ball",
              "target_ball"
            ],
            "at": "1/4",
            "measured_from": "cue_ball",
            "fraction_from_endpoint_a": 0.25,
            "resolved_location": [
              0.0,
              -0.45,
              0.0
            ],
            "endpoint_locations": [
              [
                0.0,
                -0.6,
                0.0
              ],
              [
                0.0,
                0.0,
                0.0
              ]
            ]
          }
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "A yellow one-ball placed at the quarter point of the cue-to-target line nearest the cue. The cue reaches it on frame 3 and stops there having moved only 0.12 m; the yellow ball inherits the shot, runs 0.41 m down the felt and reaches the target on frame 14. The target ends up 0.32 m along, well past the baseline's 0.12 m, because the handoff happens before the felt has taken much off the roll.",
      "ground_truth": "scenes/pool_collision/cases/edit_add_ball_near_cue/ground_truth_transforms.json",
      "thumbnail": "thumbnails/pool_collision/edit_add_ball_near_cue.jpg"
    },
    {
      "global_id": "pool_collision/edit_add_ball_midway",
      "scene": "pool_collision",
      "case_id": "edit_add_ball_midway",
      "source_case_id": "pool_collision_baseline",
      "source_video": "scenes/pool_collision/cases/pool_collision_baseline/video.mp4",
      "edited_video": "scenes/pool_collision/cases/edit_add_ball_midway/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,在母球和目标球的连线上、大致中间的位置,放一个黄色1号球。",
          "en": "From the start of the clip, place the yellow one-ball on the line between the cue ball and the target ball, about midway between them."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,在母球和目标球连线的中点放一个黄色1号球。",
          "en": "From frame 1 onwards, place the yellow one-ball at the midpoint of the line between the cue ball and the target ball."
        }
      },
      "edit_dsl": "ADD yellow_ball BETWEEN cue_ball AND target_ball AT MIDPOINT",
      "edit_kind": "ADD",
      "object_id": "yellow_ball",
      "property": null,
      "outcome_type": "object_added",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "yellow_ball": {
          "from": "absent",
          "to": "present",
          "position": {
            "on_line_between": [
              "cue_ball",
              "target_ball"
            ],
            "at": "midpoint",
            "measured_from": null,
            "fraction_from_endpoint_a": 0.5,
            "resolved_location": [
              0.0,
              -0.3,
              0.0
            ],
            "endpoint_locations": [
              [
                0.0,
                -0.6,
                0.0
              ],
              [
                0.0,
                0.0,
                0.0
              ]
            ]
          }
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "A yellow one-ball placed at the midpoint of the cue-to-target line. The shot becomes an even three-stage relay: the cue reaches it on frame 7, it reaches the target on frame 14, and each ball stops roughly where the next one started -- 0.27 m, 0.26 m and 0.31 m of travel. The clear coast between the two impacts is what separates this from the near-target case.",
      "ground_truth": "scenes/pool_collision/cases/edit_add_ball_midway/ground_truth_transforms.json",
      "thumbnail": "thumbnails/pool_collision/edit_add_ball_midway.jpg"
    },
    {
      "global_id": "pool_collision/edit_add_ball_near_target",
      "scene": "pool_collision",
      "case_id": "edit_add_ball_near_target",
      "source_case_id": "pool_collision_baseline",
      "source_video": "scenes/pool_collision/cases/pool_collision_baseline/video.mp4",
      "edited_video": "scenes/pool_collision/cases/edit_add_ball_near_target/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,在母球和目标球的连线上、靠近目标球的地方,放一个黄色1号球。",
          "en": "From the start of the clip, place the yellow one-ball on the line between the cue ball and the target ball, closer to the target ball."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,在母球和目标球连线的四等分点上放一个黄色1号球,取靠近目标球的那个。",
          "en": "From frame 1 onwards, place the yellow one-ball on the line between the cue ball and the target ball, one quarter of the way from the target ball to the cue ball."
        }
      },
      "edit_dsl": "ADD yellow_ball BETWEEN cue_ball AND target_ball AT 1/4 FROM target_ball",
      "edit_kind": "ADD",
      "object_id": "yellow_ball",
      "property": null,
      "outcome_type": "object_added",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "yellow_ball": {
          "from": "absent",
          "to": "present",
          "position": {
            "on_line_between": [
              "cue_ball",
              "target_ball"
            ],
            "at": "1/4",
            "measured_from": "target_ball",
            "fraction_from_endpoint_a": 0.75,
            "resolved_location": [
              0.0,
              -0.15,
              0.0
            ],
            "endpoint_locations": [
              [
                0.0,
                -0.6,
                0.0
              ],
              [
                0.0,
                0.0,
                0.0
              ]
            ]
          }
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "A yellow one-ball placed at the quarter point of the cue-to-target line nearest the target. The cue runs most of its baseline distance, 0.42 m, before it arrives, and the two impacts land within a frame of each other -- the second on frame 13 -- so it reads as a single crack rather than a relay. The yellow ball, blocked immediately by the target, shifts only 0.12 m while the target goes 0.31 m.",
      "ground_truth": "scenes/pool_collision/cases/edit_add_ball_near_target/ground_truth_transforms.json",
      "thumbnail": "thumbnails/pool_collision/edit_add_ball_near_target.jpg"
    },
    {
      "global_id": "pool_collision/edit_remove_target_ball",
      "scene": "pool_collision",
      "case_id": "edit_remove_target_ball",
      "source_case_id": "pool_collision_baseline",
      "source_video": "scenes/pool_collision/cases/pool_collision_baseline/video.mp4",
      "edited_video": "scenes/pool_collision/cases/edit_remove_target_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把目标球从场景中删除。",
          "en": "From the start of the clip, remove the target ball from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把目标球从场景中删除。",
          "en": "From frame 1 onwards, remove the target ball from the scene."
        }
      },
      "edit_dsl": "DELETE target_ball",
      "edit_kind": "DELETE",
      "object_id": "target_ball",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "target_ball": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Target ball removed. The cue rolls unobstructed the length of the table (~1.21 m of travel) and is still moving at 0.56 m/s when the shot ends, having reached the far cushion instead of handing its speed to another ball.",
      "ground_truth": "scenes/pool_collision/cases/edit_remove_target_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/pool_collision/edit_remove_target_ball.jpg"
    },
    {
      "global_id": "ramp_collision/edit_high_friction_red_stalls",
      "scene": "ramp_collision",
      "case_id": "edit_high_friction_red_stalls",
      "source_case_id": "ramp_baseline",
      "source_video": "scenes/ramp_collision/cases/ramp_baseline/video.mp4",
      "edited_video": "scenes/ramp_collision/cases/edit_high_friction_red_stalls/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把红球的摩擦系数调大一些。",
          "en": "From the start of the clip, increase the red ball's friction coefficient."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把红球的摩擦系数增加到原来的 3 倍。",
          "en": "From frame 1 onwards, increase the red ball's friction coefficient to 3 times its original value."
        }
      },
      "edit_dsl": "SET red_ball.friction TIMES 3",
      "edit_kind": "SET",
      "object_id": "red_ball",
      "property": "friction",
      "outcome_type": "friction_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "friction (red_ball)": {
          "from": 0.45,
          "to": 1.35
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Red ball's friction raised 3x (both the lateral coefficient and the rolling one scale together). Red rolls down the ramp but the extra rolling resistance eats it on the tabletop: it stops 21 cm short of blue and there is no collision.",
      "ground_truth": "scenes/ramp_collision/cases/edit_high_friction_red_stalls/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ramp_collision/edit_high_friction_red_stalls.jpg"
    },
    {
      "global_id": "ramp_collision/edit_remove_blue_marble",
      "scene": "ramp_collision",
      "case_id": "edit_remove_blue_marble",
      "source_case_id": "ramp_baseline",
      "source_video": "scenes/ramp_collision/cases/ramp_baseline/video.mp4",
      "edited_video": "scenes/ramp_collision/cases/edit_remove_blue_marble/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把蓝球从场景中删除。",
          "en": "From the start of the clip, remove the blue marble from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把蓝球从场景中删除。",
          "en": "From frame 1 onwards, remove the blue marble from the scene."
        }
      },
      "edit_dsl": "DELETE blue_marble",
      "edit_kind": "DELETE",
      "object_id": "blue_marble",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "blue_marble": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Blue marble removed. Red rolls down through the empty spot; yellow is off to the side and is never touched.",
      "ground_truth": "scenes/ramp_collision/cases/edit_remove_blue_marble/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ramp_collision/edit_remove_blue_marble.jpg"
    },
    {
      "global_id": "ramp_collision/edit_heavy_red_ball",
      "scene": "ramp_collision",
      "case_id": "edit_heavy_red_ball",
      "source_case_id": "ramp_baseline",
      "source_video": "scenes/ramp_collision/cases/ramp_baseline/video.mp4",
      "edited_video": "scenes/ramp_collision/cases/edit_heavy_red_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把红球的质量调大一些。",
          "en": "From the start of the clip, increase the red ball's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把红球的质量增加到原来的 20 倍。",
          "en": "From frame 1 onwards, increase the red ball's mass to 20 times its original value."
        }
      },
      "edit_dsl": "SET red_ball.mass TIMES 20",
      "edit_kind": "SET",
      "object_id": "red_ball",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (red_ball)": {
          "from": 0.05,
          "to": 1.0
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Red ball made 20x heavier. Red plows through blue almost without slowing; blue is knocked much farther than in the baseline.",
      "ground_truth": "scenes/ramp_collision/cases/edit_heavy_red_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ramp_collision/edit_heavy_red_ball.jpg"
    },
    {
      "global_id": "ramp_collision/edit_grippy_red_ball_mid_roll",
      "scene": "ramp_collision",
      "case_id": "edit_grippy_red_ball_mid_roll",
      "source_case_id": "ramp_baseline",
      "source_video": "scenes/ramp_collision/cases/ramp_baseline/video.mp4",
      "edited_video": "scenes/ramp_collision/cases/edit_grippy_red_ball_mid_roll/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "在视频前段,把红球的摩擦系数调大一些。",
          "en": "Early in the clip, increase the red ball's friction coefficient."
        },
        "quantitative": {
          "zh": "从第 18 帧开始,把红球的摩擦系数增加到原来的 3 倍。",
          "en": "From frame 18 onwards, increase the red ball's friction coefficient to 3 times its original value."
        }
      },
      "edit_dsl": "SET red_ball.friction TIMES 3 AT FRAME 18",
      "edit_kind": "SET",
      "object_id": "red_ball",
      "property": "friction",
      "outcome_type": "friction_increase",
      "applies_from_frame": 18,
      "timing": "partway",
      "physics_diff": {
        "friction (red_ball)": {
          "from": 0.45,
          "to": 1.35
        },
        "timing": {
          "applies_from_frame": 18,
          "total_frames": 96,
          "unedited_frames": [
            1,
            17
          ]
        }
      },
      "edit_summary": "Red ball's friction raised 3x at frame 18, once it is already off the ramp and running at full speed. Frames 1-17 are the source video frame for frame; from 18 red visibly slows and comes to rest at frame 27, 0.0068 m short of the blue marble -- it grinds to a halt against blue's edge without touching it, so neither marble is ever moved. The whole-clip version of the same edit (edit_high_friction_red_stalls) stalls red 0.21 m short instead: same factor, different frame, different video.",
      "ground_truth": "scenes/ramp_collision/cases/edit_grippy_red_ball_mid_roll/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ramp_collision/edit_grippy_red_ball_mid_roll.jpg"
    },
    {
      "global_id": "ramp_collision/edit_heavy_blue_marble",
      "scene": "ramp_collision",
      "case_id": "edit_heavy_blue_marble",
      "source_case_id": "ramp_baseline",
      "source_video": "scenes/ramp_collision/cases/ramp_baseline/video.mp4",
      "edited_video": "scenes/ramp_collision/cases/edit_heavy_blue_marble/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把蓝球的质量调大一些。",
          "en": "From the start of the clip, increase the blue marble's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把蓝球的质量增加到原来的 40 倍。",
          "en": "From frame 1 onwards, increase the blue marble's mass to 40 times its original value."
        }
      },
      "edit_dsl": "SET blue_marble.mass TIMES 40",
      "edit_kind": "SET",
      "object_id": "blue_marble",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (blue_marble)": {
          "from": 0.05,
          "to": 2.0
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Blue marble made 40x heavier. Red hits blue and stops dead; blue barely moves instead of rolling forward like in the baseline.",
      "ground_truth": "scenes/ramp_collision/cases/edit_heavy_blue_marble/ground_truth_transforms.json",
      "thumbnail": "thumbnails/ramp_collision/edit_heavy_blue_marble.jpg"
    },
    {
      "global_id": "table_drop_collision/edit_heavy_rolling_ball",
      "scene": "table_drop_collision",
      "case_id": "edit_heavy_rolling_ball",
      "source_case_id": "table_drop_collision_baseline",
      "source_video": "scenes/table_drop_collision/cases/table_drop_collision_baseline/video.mp4",
      "edited_video": "scenes/table_drop_collision/cases/edit_heavy_rolling_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把新网球的质量调大一些。",
          "en": "From the start of the clip, increase the new tennis ball's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把新网球的质量增加到原来的 5 倍。",
          "en": "From frame 1 onwards, increase the new tennis ball's mass to 5 times its original value."
        }
      },
      "edit_dsl": "SET rolling_ball.mass TIMES 5",
      "edit_kind": "SET",
      "object_id": "rolling_ball",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (rolling_ball)": {
          "from": 0.057,
          "to": 0.285
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Rolling ball made 5x heavier. The impact now carries much more momentum into the target: it rockets 1.64 m across the floor (5x the baseline's 0.30 m), and the rolling ball keeps driving on behind it, ending 0.98 m past the lip instead of 0.74 m.",
      "ground_truth": "scenes/table_drop_collision/cases/edit_heavy_rolling_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/table_drop_collision/edit_heavy_rolling_ball.jpg"
    },
    {
      "global_id": "table_drop_collision/edit_light_rolling_ball",
      "scene": "table_drop_collision",
      "case_id": "edit_light_rolling_ball",
      "source_case_id": "table_drop_collision_baseline",
      "source_video": "scenes/table_drop_collision/cases/table_drop_collision_baseline/video.mp4",
      "edited_video": "scenes/table_drop_collision/cases/edit_light_rolling_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把新网球的质量调小一些。",
          "en": "From the start of the clip, decrease the new tennis ball's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把新网球的质量减少到原来的 0.25 倍。",
          "en": "From frame 1 onwards, reduce the new tennis ball's mass to 0.25 times its original value."
        }
      },
      "edit_dsl": "SET rolling_ball.mass TIMES 0.25",
      "edit_kind": "SET",
      "object_id": "rolling_ball",
      "property": "mass",
      "outcome_type": "mass_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (rolling_ball)": {
          "from": 0.057,
          "to": 0.01425
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "New tennis ball made four times lighter. It still lands on the old one but bounces off it rather than driving it: the old ball barely moves, 0.03 m against the baseline's 0.30 m, and the light ball comes to rest 0.52 m from its start instead of 0.88 m.",
      "ground_truth": "scenes/table_drop_collision/cases/edit_light_rolling_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/table_drop_collision/edit_light_rolling_ball.jpg"
    },
    {
      "global_id": "table_drop_collision/edit_heavy_target_ball",
      "scene": "table_drop_collision",
      "case_id": "edit_heavy_target_ball",
      "source_case_id": "table_drop_collision_baseline",
      "source_video": "scenes/table_drop_collision/cases/table_drop_collision_baseline/video.mp4",
      "edited_video": "scenes/table_drop_collision/cases/edit_heavy_target_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把旧网球的质量调大一些。",
          "en": "From the start of the clip, increase the old tennis ball's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把旧网球的质量增加到原来的 5 倍。",
          "en": "From frame 1 onwards, increase the old tennis ball's mass to 5 times its original value."
        }
      },
      "edit_dsl": "SET target_ball.mass TIMES 5",
      "edit_kind": "SET",
      "object_id": "target_ball",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (target_ball)": {
          "from": 0.057,
          "to": 0.285
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Target ball made 5x heavier. The rolling ball hits a wall of mass and rebounds backward -- ending up EAST of the lip instead of west of it -- and the target only creeps 0.02 m instead of the baseline's 0.30 m.",
      "ground_truth": "scenes/table_drop_collision/cases/edit_heavy_target_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/table_drop_collision/edit_heavy_target_ball.jpg"
    },
    {
      "global_id": "table_drop_collision/edit_soft_push",
      "scene": "table_drop_collision",
      "case_id": "edit_soft_push",
      "source_case_id": "table_drop_collision_baseline",
      "source_video": "scenes/table_drop_collision/cases/table_drop_collision_baseline/video.mp4",
      "edited_video": "scenes/table_drop_collision/cases/edit_soft_push/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把新网球的初速度大小调小一些。",
          "en": "From the start of the clip, decrease the new tennis ball's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把新网球的初速度大小减少到原来的 0.6 倍。",
          "en": "From frame 1 onwards, reduce the new tennis ball's initial speed to 0.6 times its original value."
        }
      },
      "edit_dsl": "SET rolling_ball.initial_velocity TIMES 0.6",
      "edit_kind": "SET",
      "object_id": "rolling_ball",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (rolling_ball)": {
          "from": 1.28,
          "to": 0.768
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "New tennis ball pushed more gently across the table. It reaches the lip at lower speed, is thrown less far off the edge, and lands short of the old ball -- no contact at all. The old ball stays exactly where it started, where the baseline moves it 0.30 m; the new ball bounces its way out across the floor alone, nine hops against the baseline's five.",
      "ground_truth": "scenes/table_drop_collision/cases/edit_soft_push/ground_truth_transforms.json",
      "thumbnail": "thumbnails/table_drop_collision/edit_soft_push.jpg"
    },
    {
      "global_id": "table_drop_collision/edit_dead_rolling_ball",
      "scene": "table_drop_collision",
      "case_id": "edit_dead_rolling_ball",
      "source_case_id": "table_drop_collision_baseline",
      "source_video": "scenes/table_drop_collision/cases/table_drop_collision_baseline/video.mp4",
      "edited_video": "scenes/table_drop_collision/cases/edit_dead_rolling_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把新网球的恢复系数调小一些。",
          "en": "From the start of the clip, decrease the new tennis ball's restitution."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把新网球的恢复系数减少到原来的 0.1 倍。",
          "en": "From frame 1 onwards, reduce the new tennis ball's restitution to 0.1 times its original value."
        }
      },
      "edit_dsl": "SET rolling_ball.restitution TIMES 0.1",
      "edit_kind": "SET",
      "object_id": "rolling_ball",
      "property": "restitution",
      "outcome_type": "restitution_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "restitution (rolling_ball)": {
          "from": 0.86,
          "to": 0.086
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "New tennis ball's restitution killed. Its floor bounce and its impact against the old ball both go inelastic: it stops bouncing entirely -- no hops against the baseline's five -- and the pair sticks rather than transferring cleanly. The old ball moves only 0.12 m instead of 0.30 m, while the new one drives on to 1.09 m from its start against 0.88 m.",
      "ground_truth": "scenes/table_drop_collision/cases/edit_dead_rolling_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/table_drop_collision/edit_dead_rolling_ball.jpg"
    },
    {
      "global_id": "table_drop_collision/edit_remove_target_ball",
      "scene": "table_drop_collision",
      "case_id": "edit_remove_target_ball",
      "source_case_id": "table_drop_collision_baseline",
      "source_video": "scenes/table_drop_collision/cases/table_drop_collision_baseline/video.mp4",
      "edited_video": "scenes/table_drop_collision/cases/edit_remove_target_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把旧网球从场景中删除。",
          "en": "From the start of the clip, remove the old tennis ball from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把旧网球从场景中删除。",
          "en": "From frame 1 onwards, remove the old tennis ball from the scene."
        }
      },
      "edit_dsl": "DELETE target_ball",
      "edit_kind": "DELETE",
      "object_id": "target_ball",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "target_ball": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Target ball removed. The rolling ball leaves the table and lands on the rug exactly where the baseline predicts -- (-0.67, -0.29) -- and, with nothing to strike, rolls on unobstructed for 1.18 m before friction stops it.",
      "ground_truth": "scenes/table_drop_collision/cases/edit_remove_target_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/table_drop_collision/edit_remove_target_ball.jpg"
    },
    {
      "global_id": "table_marble_collision/edit_heavy_small_marble",
      "scene": "table_marble_collision",
      "case_id": "edit_heavy_small_marble",
      "source_case_id": "table_marble_collision_baseline",
      "source_video": "scenes/table_marble_collision/cases/table_marble_collision_baseline/video.mp4",
      "edited_video": "scenes/table_marble_collision/cases/edit_heavy_small_marble/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把小玻璃球的质量调大一些。",
          "en": "From the start of the clip, increase the small marble's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把小玻璃球的质量增加到原来的 5 倍。",
          "en": "From frame 1 onwards, increase the small marble's mass to 5 times its original value."
        }
      },
      "edit_dsl": "SET small_marble.mass TIMES 5",
      "edit_kind": "SET",
      "object_id": "small_marble",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (small_marble)": {
          "from": 0.1636246173744684,
          "to": 0.8181230869
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Small marble made five times heavier, so the mass ratio drops from 8:1 to about 1.6:1. It barely reacts to the hit -- 0.29 m against the baseline's 0.68 m -- while the big marble is checked hard on impact and rolls only 0.70 m instead of 0.89 m.",
      "ground_truth": "scenes/table_marble_collision/cases/edit_heavy_small_marble/ground_truth_transforms.json",
      "thumbnail": "thumbnails/table_marble_collision/edit_heavy_small_marble.jpg"
    },
    {
      "global_id": "table_marble_collision/edit_heavy_big_marble",
      "scene": "table_marble_collision",
      "case_id": "edit_heavy_big_marble",
      "source_case_id": "table_marble_collision_baseline",
      "source_video": "scenes/table_marble_collision/cases/table_marble_collision_baseline/video.mp4",
      "edited_video": "scenes/table_marble_collision/cases/edit_heavy_big_marble/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把大玻璃球的质量调大一些。",
          "en": "From the start of the clip, increase the big marble's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把大玻璃球的质量增加到原来的 5 倍。",
          "en": "From frame 1 onwards, increase the big marble's mass to 5 times its original value."
        }
      },
      "edit_dsl": "SET big_marble.mass TIMES 5",
      "edit_kind": "SET",
      "object_id": "big_marble",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (big_marble)": {
          "from": 1.3089969389957472,
          "to": 6.544984695
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Big marble made 5x heavier (1.309 -> 6.545 kg). The mass ratio is now 40:1 instead of 8:1, so the impact drives even more momentum into the small marble: it rockets 0.85 m along the table (vs 0.68 m baseline). The big marble follows through almost undisturbed.",
      "ground_truth": "scenes/table_marble_collision/cases/edit_heavy_big_marble/ground_truth_transforms.json",
      "thumbnail": "thumbnails/table_marble_collision/edit_heavy_big_marble.jpg"
    },
    {
      "global_id": "table_marble_collision/edit_matched_pair",
      "scene": "table_marble_collision",
      "case_id": "edit_matched_pair",
      "source_case_id": "table_marble_collision_baseline",
      "source_video": "scenes/table_marble_collision/cases/table_marble_collision_baseline/video.mp4",
      "edited_video": "scenes/table_marble_collision/cases/edit_matched_pair/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把大玻璃球的质量调小一些。",
          "en": "From the start of the clip, decrease the big marble's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把大玻璃球的质量减少到原来的 0.125 倍。",
          "en": "From frame 1 onwards, reduce the big marble's mass to 0.125 times its original value."
        }
      },
      "edit_dsl": "SET big_marble.mass TIMES 0.125",
      "edit_kind": "SET",
      "object_id": "big_marble",
      "property": "mass",
      "outcome_type": "mass_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (big_marble)": {
          "from": 1.3089969389957472,
          "to": 0.1636246174
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Big marble made exactly as heavy as the small one: it is twice the radius, so an eighth of its mass is the small one's mass, and the ratio goes from 8:1 to 1:1. The hit becomes an equal-mass exchange -- the big one is stopped short at 0.66 m against the baseline's 0.89 m, and the small one is nudged only 0.18 m, because table friction damps most of the transfer between two light marbles.",
      "ground_truth": "scenes/table_marble_collision/cases/edit_matched_pair/ground_truth_transforms.json",
      "thumbnail": "thumbnails/table_marble_collision/edit_matched_pair.jpg"
    },
    {
      "global_id": "table_marble_collision/edit_soft_push",
      "scene": "table_marble_collision",
      "case_id": "edit_soft_push",
      "source_case_id": "table_marble_collision_baseline",
      "source_video": "scenes/table_marble_collision/cases/table_marble_collision_baseline/video.mp4",
      "edited_video": "scenes/table_marble_collision/cases/edit_soft_push/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把大玻璃球的初速度大小调小一些。",
          "en": "From the start of the clip, decrease the big marble's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把大玻璃球的初速度大小减少到原来的 0.7 倍。",
          "en": "From frame 1 onwards, reduce the big marble's initial speed to 0.7 times its original value."
        }
      },
      "edit_dsl": "SET big_marble.initial_velocity TIMES 0.7",
      "edit_kind": "SET",
      "object_id": "big_marble",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (big_marble)": {
          "from": 1.31,
          "to": 0.917
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Big marble pushed more gently. It slows against table friction and stops short of the small marble -- 0.49 m of travel against the baseline's 0.89 -- so no contact happens at all. The small marble sits untouched for the whole shot.",
      "ground_truth": "scenes/table_marble_collision/cases/edit_soft_push/ground_truth_transforms.json",
      "thumbnail": "thumbnails/table_marble_collision/edit_soft_push.jpg"
    },
    {
      "global_id": "table_marble_collision/edit_dead_small_marble",
      "scene": "table_marble_collision",
      "case_id": "edit_dead_small_marble",
      "source_case_id": "table_marble_collision_baseline",
      "source_video": "scenes/table_marble_collision/cases/table_marble_collision_baseline/video.mp4",
      "edited_video": "scenes/table_marble_collision/cases/edit_dead_small_marble/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把小玻璃球的恢复系数调小一些。",
          "en": "From the start of the clip, decrease the small marble's restitution."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把小玻璃球的恢复系数减少到原来的 0.05 倍。",
          "en": "From frame 1 onwards, reduce the small marble's restitution to 0.05 times its original value."
        }
      },
      "edit_dsl": "SET small_marble.restitution TIMES 0.05",
      "edit_kind": "SET",
      "object_id": "small_marble",
      "property": "restitution",
      "outcome_type": "restitution_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "restitution (small_marble)": {
          "from": 0.87,
          "to": 0.0435
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Small marble's restitution killed. The impact goes almost fully inelastic: the small marble absorbs the collision instead of springing away, moving 0.26 m against the baseline's 0.68 m, while the big marble is barely checked and drives on to 0.93 m rather than being handed off cleanly.",
      "ground_truth": "scenes/table_marble_collision/cases/edit_dead_small_marble/ground_truth_transforms.json",
      "thumbnail": "thumbnails/table_marble_collision/edit_dead_small_marble.jpg"
    },
    {
      "global_id": "table_marble_collision/edit_remove_small_marble",
      "scene": "table_marble_collision",
      "case_id": "edit_remove_small_marble",
      "source_case_id": "table_marble_collision_baseline",
      "source_video": "scenes/table_marble_collision/cases/table_marble_collision_baseline/video.mp4",
      "edited_video": "scenes/table_marble_collision/cases/edit_remove_small_marble/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把小玻璃球从场景中删除。",
          "en": "From the start of the clip, remove the small marble from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把小玻璃球从场景中删除。",
          "en": "From frame 1 onwards, remove the small marble from the scene."
        }
      },
      "edit_dsl": "DELETE small_marble",
      "edit_kind": "DELETE",
      "object_id": "small_marble",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "small_marble": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Small marble removed. The big marble rolls across the bar table unobstructed -- 1.01 m of travel instead of the baseline's 0.89 m -- and never hits anything.",
      "ground_truth": "scenes/table_marble_collision/cases/edit_remove_small_marble/ground_truth_transforms.json",
      "thumbnail": "thumbnails/table_marble_collision/edit_remove_small_marble.jpg"
    },
    {
      "global_id": "tennis_flight/edit_slick_ball",
      "scene": "tennis_flight",
      "case_id": "edit_slick_ball",
      "source_case_id": "tennis_flight_baseline",
      "source_video": "scenes/tennis_flight/cases/tennis_flight_baseline/video.mp4",
      "edited_video": "scenes/tennis_flight/cases/edit_slick_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把网球的摩擦系数调小一些。",
          "en": "From the start of the clip, decrease the tennis ball's friction coefficient."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把网球的摩擦系数减少到原来的 0.2 倍。",
          "en": "From frame 1 onwards, reduce the tennis ball's friction coefficient to 0.2 times its original value."
        }
      },
      "edit_dsl": "SET ball.friction TIMES 0.2",
      "edit_kind": "SET",
      "object_id": "ball",
      "property": "friction",
      "outcome_type": "friction_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "friction (ball)": {
          "from": 0.5,
          "to": 0.1
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Ball's friction cut 5x -- both lateral and rolling coefficients scale together. After the same landing at x=1.06 the ball meets almost no grip on the court and is still rolling fast at the end of the 4 s window, having reached x=8.8 m -- roughly 2.6x the baseline's 3.3 m roll-out.",
      "ground_truth": "scenes/tennis_flight/cases/edit_slick_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/tennis_flight/edit_slick_ball.jpg"
    },
    {
      "global_id": "tennis_flight/edit_grippy_ball",
      "scene": "tennis_flight",
      "case_id": "edit_grippy_ball",
      "source_case_id": "tennis_flight_baseline",
      "source_video": "scenes/tennis_flight/cases/tennis_flight_baseline/video.mp4",
      "edited_video": "scenes/tennis_flight/cases/edit_grippy_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把网球的摩擦系数调大一些。",
          "en": "From the start of the clip, increase the tennis ball's friction coefficient."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把网球的摩擦系数增加到原来的 3 倍。",
          "en": "From frame 1 onwards, increase the tennis ball's friction coefficient to 3 times its original value."
        }
      },
      "edit_dsl": "SET ball.friction TIMES 3",
      "edit_kind": "SET",
      "object_id": "ball",
      "property": "friction",
      "outcome_type": "friction_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "friction (ball)": {
          "from": 0.5,
          "to": 1.5
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Ball's friction tripled. After the same landing at x=1.05 the high-friction contact eats the roll almost immediately: the ball stops essentially at its landing point (final x=1.38 m vs 3.31 m baseline), no meaningful run-out.",
      "ground_truth": "scenes/tennis_flight/cases/edit_grippy_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/tennis_flight/edit_grippy_ball.jpg"
    },
    {
      "global_id": "tennis_flight/edit_bouncy_ball",
      "scene": "tennis_flight",
      "case_id": "edit_bouncy_ball",
      "source_case_id": "tennis_flight_baseline",
      "source_video": "scenes/tennis_flight/cases/tennis_flight_baseline/video.mp4",
      "edited_video": "scenes/tennis_flight/cases/edit_bouncy_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把网球的恢复系数调大一些。",
          "en": "From the start of the clip, increase the tennis ball's restitution."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把网球的恢复系数增加到原来的 18 倍。",
          "en": "From frame 1 onwards, increase the tennis ball's restitution to 18 times its original value."
        }
      },
      "edit_dsl": "SET ball.restitution TIMES 18",
      "edit_kind": "SET",
      "object_id": "ball",
      "property": "restitution",
      "outcome_type": "restitution_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "restitution (ball)": {
          "from": 0.05,
          "to": 0.9
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Ball's restitution 18x higher -- from a dead thud (0.05) to a near-perfect bounce (0.9). The first landing at x=1.05 is the same, but instead of pancaking the ball hops several times along +X before settling (final x=3.48 m vs 3.31 m baseline), with the visible bounces being the tell.",
      "ground_truth": "scenes/tennis_flight/cases/edit_bouncy_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/tennis_flight/edit_bouncy_ball.jpg"
    },
    {
      "global_id": "tennis_flight/edit_soft_serve",
      "scene": "tennis_flight",
      "case_id": "edit_soft_serve",
      "source_case_id": "tennis_flight_baseline",
      "source_video": "scenes/tennis_flight/cases/tennis_flight_baseline/video.mp4",
      "edited_video": "scenes/tennis_flight/cases/edit_soft_serve/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把网球的初速度大小调小一些。",
          "en": "From the start of the clip, decrease the tennis ball's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把网球的初速度大小减少到原来的 0.6 倍。",
          "en": "From frame 1 onwards, reduce the tennis ball's initial speed to 0.6 times its original value."
        }
      },
      "edit_dsl": "SET ball.initial_velocity TIMES 0.6",
      "edit_kind": "SET",
      "object_id": "ball",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (ball)": {
          "from": 4.5,
          "to": 2.7
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Serve struck at a little over half the baseline speed. The ball no longer clears the net: it lands short and finishes at x=-0.12, still on the near side, where the baseline carries through to x=+3.31.",
      "ground_truth": "scenes/tennis_flight/cases/edit_soft_serve/ground_truth_transforms.json",
      "thumbnail": "thumbnails/tennis_flight/edit_soft_serve.jpg"
    },
    {
      "global_id": "tennis_flight/edit_hard_serve",
      "scene": "tennis_flight",
      "case_id": "edit_hard_serve",
      "source_case_id": "tennis_flight_baseline",
      "source_video": "scenes/tennis_flight/cases/tennis_flight_baseline/video.mp4",
      "edited_video": "scenes/tennis_flight/cases/edit_hard_serve/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把网球的初速度大小调大一些。",
          "en": "From the start of the clip, increase the tennis ball's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把网球的初速度大小增加到原来的 1.5 倍。",
          "en": "From frame 1 onwards, increase the tennis ball's initial speed to 1.5 times its original value."
        }
      },
      "edit_dsl": "SET ball.initial_velocity TIMES 1.5",
      "edit_kind": "SET",
      "object_id": "ball",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (ball)": {
          "from": 4.5,
          "to": 6.75
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Serve struck half again as hard. The ball flies further before touching down and, still carrying energy after landing, rolls out to x=+7.64 by the end of the 4 s window -- more than twice the baseline's x=+3.31.",
      "ground_truth": "scenes/tennis_flight/cases/edit_hard_serve/ground_truth_transforms.json",
      "thumbnail": "thumbnails/tennis_flight/edit_hard_serve.jpg"
    },
    {
      "global_id": "toy_car_ball/edit_soft_push",
      "scene": "toy_car_ball",
      "case_id": "edit_soft_push",
      "source_case_id": "toy_car_ball_baseline",
      "source_video": "scenes/toy_car_ball/cases/toy_car_ball_baseline/video.mp4",
      "edited_video": "scenes/toy_car_ball/cases/edit_soft_push/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把玩具小车的初速度大小调小一些。",
          "en": "From the start of the clip, decrease the toy car's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把玩具小车的初速度大小减少到原来的 0.6 倍。",
          "en": "From frame 1 onwards, reduce the toy car's initial speed to 0.6 times its original value."
        }
      },
      "edit_dsl": "SET toy_car.initial_velocity TIMES 0.6",
      "edit_kind": "SET",
      "object_id": "toy_car",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (toy_car)": {
          "from": 0.6,
          "to": 0.36
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Car pushed more gently. Table friction bleeds off the push before the car ever reaches the ball: it coasts 0.15 m and stops, still on the table, and the ball sits untouched near the edge for the whole shot -- no collision and no fall, where the baseline knocks it 0.89 m off the shelf.",
      "ground_truth": "scenes/toy_car_ball/cases/edit_soft_push/ground_truth_transforms.json",
      "thumbnail": "thumbnails/toy_car_ball/edit_soft_push.jpg"
    },
    {
      "global_id": "toy_car_ball/edit_hard_push",
      "scene": "toy_car_ball",
      "case_id": "edit_hard_push",
      "source_case_id": "toy_car_ball_baseline",
      "source_video": "scenes/toy_car_ball/cases/toy_car_ball_baseline/video.mp4",
      "edited_video": "scenes/toy_car_ball/cases/edit_hard_push/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把玩具小车的初速度大小调大一些。",
          "en": "From the start of the clip, increase the toy car's initial speed."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把玩具小车的初速度大小增加到原来的 1.5 倍。",
          "en": "From frame 1 onwards, increase the toy car's initial speed to 1.5 times its original value."
        }
      },
      "edit_dsl": "SET toy_car.initial_velocity TIMES 1.5",
      "edit_kind": "SET",
      "object_id": "toy_car",
      "property": "initial_velocity",
      "outcome_type": "initial_velocity_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "initial_velocity (toy_car)": {
          "from": 0.6,
          "to": 0.9
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Car pushed 50% harder (0.6 -> 0.9 m/s). The heavier hit sends the ball flying off the edge much further: it lands and rolls out to x=-2.42 m, more than twice the baseline's 1.08 m. The car itself also flies off behind it.",
      "ground_truth": "scenes/toy_car_ball/cases/edit_hard_push/ground_truth_transforms.json",
      "thumbnail": "thumbnails/toy_car_ball/edit_hard_push.jpg"
    },
    {
      "global_id": "toy_car_ball/edit_heavy_ball",
      "scene": "toy_car_ball",
      "case_id": "edit_heavy_ball",
      "source_case_id": "toy_car_ball_baseline",
      "source_video": "scenes/toy_car_ball/cases/toy_car_ball_baseline/video.mp4",
      "edited_video": "scenes/toy_car_ball/cases/edit_heavy_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把玩具球的质量调大一些。",
          "en": "From the start of the clip, increase the toy ball's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把玩具球的质量增加到原来的 20 倍。",
          "en": "From frame 1 onwards, increase the toy ball's mass to 20 times its original value."
        }
      },
      "edit_dsl": "SET toy_ball.mass TIMES 20",
      "edit_kind": "SET",
      "object_id": "toy_ball",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (toy_ball)": {
          "from": 0.05,
          "to": 1.0
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Ball made twenty times heavier, 0.05 kg to 1.0 kg, which puts it at three times the car's own mass. The car still crosses the shelf and reaches it -- 0.36 m of travel against the baseline's 0.40 m, stopping against the ball rather than driving through it -- but it no longer has the momentum to move it: the ball shifts 24 mm and stays on the shelf, where the baseline sends it over the edge and 0.89 m down to the floor. What separates this from edit_soft_push is that the collision does happen; the car arrives and is stopped by the ball instead of running out of push half-way there.",
      "ground_truth": "scenes/toy_car_ball/cases/edit_heavy_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/toy_car_ball/edit_heavy_ball.jpg"
    },
    {
      "global_id": "toy_car_ball/edit_bouncy_ball",
      "scene": "toy_car_ball",
      "case_id": "edit_bouncy_ball",
      "source_case_id": "toy_car_ball_baseline",
      "source_video": "scenes/toy_car_ball/cases/toy_car_ball_baseline/video.mp4",
      "edited_video": "scenes/toy_car_ball/cases/edit_bouncy_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把玩具球的恢复系数调大一些。",
          "en": "From the start of the clip, increase the toy ball's restitution."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把玩具球的恢复系数增加到原来的 1.5 倍。",
          "en": "From frame 1 onwards, increase the toy ball's restitution to 1.5 times its original value."
        }
      },
      "edit_dsl": "SET toy_ball.restitution TIMES 1.5",
      "edit_kind": "SET",
      "object_id": "toy_ball",
      "property": "restitution",
      "outcome_type": "restitution_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "restitution (toy_ball)": {
          "from": 0.6,
          "to": 0.9
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Ball's restitution raised by half, to a near-elastic 0.90. It is still knocked off the shelf, but instead of settling on the floor it keeps bouncing through the rest of the shot -- five hops against the baseline's two -- and is still 0.17 m up and moving at 0.23 m/s when the clip ends.",
      "ground_truth": "scenes/toy_car_ball/cases/edit_bouncy_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/toy_car_ball/edit_bouncy_ball.jpg"
    },
    {
      "global_id": "toy_car_ball/edit_remove_toy_ball",
      "scene": "toy_car_ball",
      "case_id": "edit_remove_toy_ball",
      "source_case_id": "toy_car_ball_baseline",
      "source_video": "scenes/toy_car_ball/cases/toy_car_ball_baseline/video.mp4",
      "edited_video": "scenes/toy_car_ball/cases/edit_remove_toy_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把玩具球从场景中删除。",
          "en": "From the start of the clip, remove the toy ball from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把玩具球从场景中删除。",
          "en": "From frame 1 onwards, remove the toy ball from the scene."
        }
      },
      "edit_dsl": "DELETE toy_ball",
      "edit_kind": "DELETE",
      "object_id": "toy_ball",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "toy_ball": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Ball removed. The car drives across an empty shelf and reaches the far edge without hitting anything; no fall, no collision. The car itself comes to rest near the edge instead of being knocked off behind the ball as in the baseline.",
      "ground_truth": "scenes/toy_car_ball/cases/edit_remove_toy_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/toy_car_ball/edit_remove_toy_ball.jpg"
    },
    {
      "global_id": "toy_car_ball/edit_remove_toy_ball_after_push",
      "scene": "toy_car_ball",
      "case_id": "edit_remove_toy_ball_after_push",
      "source_case_id": "toy_car_ball_baseline",
      "source_video": "scenes/toy_car_ball/cases/toy_car_ball_baseline/video.mp4",
      "edited_video": "scenes/toy_car_ball/cases/edit_remove_toy_ball_after_push/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "在视频前段,把玩具球从场景中删除。",
          "en": "Early in the clip, remove the toy ball from the scene."
        },
        "quantitative": {
          "zh": "从第 18 帧开始,把玩具球从场景中删除。",
          "en": "From frame 18 onwards, remove the toy ball from the scene."
        }
      },
      "edit_dsl": "DELETE toy_ball AT FRAME 18",
      "edit_kind": "DELETE",
      "object_id": "toy_ball",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 18,
      "timing": "partway",
      "physics_diff": {
        "toy_ball": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 18,
          "total_frames": 96,
          "unedited_frames": [
            1,
            17
          ]
        }
      },
      "edit_summary": "Ball removed at frame 18, six frames after the car reaches it at frame 12. Frames 1-17 are the source video frame for frame: the car noses into the ball and starts it rolling, and the ball is 0.07 m along when it disappears -- well short of the table edge it rolls off in the source. The car carries on exactly as in the source, stopping at x=-0.27. The whole-clip version of the same delete has nothing to push against at all: the car runs 0.05 m further, to x=-0.32.",
      "ground_truth": "scenes/toy_car_ball/cases/edit_remove_toy_ball_after_push/ground_truth_transforms.json",
      "thumbnail": "thumbnails/toy_car_ball/edit_remove_toy_ball_after_push.jpg"
    },
    {
      "global_id": "twin_ramp_collision/edit_heavy_purple_ball",
      "scene": "twin_ramp_collision",
      "case_id": "edit_heavy_purple_ball",
      "source_case_id": "twin_ramp_collision_baseline",
      "source_video": "scenes/twin_ramp_collision/cases/twin_ramp_collision_baseline/video.mp4",
      "edited_video": "scenes/twin_ramp_collision/cases/edit_heavy_purple_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把紫色玻璃球的质量调大一些。",
          "en": "From the start of the clip, increase the purple marble's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把紫色玻璃球的质量增加到原来的 5 倍。",
          "en": "From frame 1 onwards, increase the purple marble's mass to 5 times its original value."
        }
      },
      "edit_dsl": "SET purple_ball.mass TIMES 5",
      "edit_kind": "SET",
      "object_id": "purple_ball",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (purple_ball)": {
          "from": 0.343,
          "to": 1.715
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Purple marble made five times heavier. Same approach speeds, but the heavier purple ploughs through the impact and the light yellow one is thrown all the way back up its own ramp and off it: yellow ends at x=-1.07 against the baseline's x=-0.08. Purple carries on through the meeting point to x=+0.02, still moving at 0.21 m/s.",
      "ground_truth": "scenes/twin_ramp_collision/cases/edit_heavy_purple_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/twin_ramp_collision/edit_heavy_purple_ball.jpg"
    },
    {
      "global_id": "twin_ramp_collision/edit_light_purple_ball",
      "scene": "twin_ramp_collision",
      "case_id": "edit_light_purple_ball",
      "source_case_id": "twin_ramp_collision_baseline",
      "source_video": "scenes/twin_ramp_collision/cases/twin_ramp_collision_baseline/video.mp4",
      "edited_video": "scenes/twin_ramp_collision/cases/edit_light_purple_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把紫色玻璃球的质量调小一些。",
          "en": "From the start of the clip, decrease the purple marble's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把紫色玻璃球的质量减少到原来的 0.3 倍。",
          "en": "From frame 1 onwards, reduce the purple marble's mass to 0.3 times its original value."
        }
      },
      "edit_dsl": "SET purple_ball.mass TIMES 0.3",
      "edit_kind": "SET",
      "object_id": "purple_ball",
      "property": "mass",
      "outcome_type": "mass_decrease",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (purple_ball)": {
          "from": 0.343,
          "to": 0.1029
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Purple marble made a little under a third of its weight. The exchange no longer checks it: purple carries through the meeting point to x=-0.01 after 0.62 m, reaching 1.54 m/s along the way against the baseline's 0.93, while yellow is stopped and left at x=-0.09 still drifting at 0.23 m/s. The two end up almost on top of each other near the centre of the track, where the baseline leaves them 0.15 m apart astride it.",
      "ground_truth": "scenes/twin_ramp_collision/cases/edit_light_purple_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/twin_ramp_collision/edit_light_purple_ball.jpg"
    },
    {
      "global_id": "twin_ramp_collision/edit_heavy_yellow_ball",
      "scene": "twin_ramp_collision",
      "case_id": "edit_heavy_yellow_ball",
      "source_case_id": "twin_ramp_collision_baseline",
      "source_video": "scenes/twin_ramp_collision/cases/twin_ramp_collision_baseline/video.mp4",
      "edited_video": "scenes/twin_ramp_collision/cases/edit_heavy_yellow_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把黄色玻璃球的质量调大一些。",
          "en": "From the start of the clip, increase the yellow marble's mass."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把黄色玻璃球的质量增加到原来的 5 倍。",
          "en": "From frame 1 onwards, increase the yellow marble's mass to 5 times its original value."
        }
      },
      "edit_dsl": "SET yellow_ball.mass TIMES 5",
      "edit_kind": "SET",
      "object_id": "yellow_ball",
      "property": "mass",
      "outcome_type": "mass_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "mass (yellow_ball)": {
          "from": 0.343,
          "to": 1.715
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Yellow marble made five times heavier -- the mirror of the heavy-purple edit. Yellow ploughs through and purple is thrown the full length back up its own ramp, ending at x=+1.09 against the baseline's x=+0.07, while yellow carries on to x=-0.01 still moving at 0.20 m/s.",
      "ground_truth": "scenes/twin_ramp_collision/cases/edit_heavy_yellow_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/twin_ramp_collision/edit_heavy_yellow_ball.jpg"
    },
    {
      "global_id": "twin_ramp_collision/edit_grippy_purple_ball",
      "scene": "twin_ramp_collision",
      "case_id": "edit_grippy_purple_ball",
      "source_case_id": "twin_ramp_collision_baseline",
      "source_video": "scenes/twin_ramp_collision/cases/twin_ramp_collision_baseline/video.mp4",
      "edited_video": "scenes/twin_ramp_collision/cases/edit_grippy_purple_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把紫色玻璃球的摩擦系数调大一些。",
          "en": "From the start of the clip, increase the purple marble's friction coefficient."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把紫色玻璃球的摩擦系数增加到原来的 10 倍。",
          "en": "From frame 1 onwards, increase the purple marble's friction coefficient to 10 times its original value."
        }
      },
      "edit_dsl": "SET purple_ball.friction TIMES 10",
      "edit_kind": "SET",
      "object_id": "purple_ball",
      "property": "friction",
      "outcome_type": "friction_increase",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "friction (purple_ball)": {
          "from": 0.3,
          "to": 3.0
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Purple marble's friction 10x higher -- both lateral and rolling coefficients scale together. Rolling resistance now dominates: purple never reaches the valley (final x=+0.61 m, essentially where its ramp meets the plank), so no collision happens. Blue rolls in unopposed and drifts past the middle to x=+0.27 m still moving at 0.52 m/s.",
      "ground_truth": "scenes/twin_ramp_collision/cases/edit_grippy_purple_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/twin_ramp_collision/edit_grippy_purple_ball.jpg"
    },
    {
      "global_id": "twin_ramp_collision/edit_remove_purple_ball",
      "scene": "twin_ramp_collision",
      "case_id": "edit_remove_purple_ball",
      "source_case_id": "twin_ramp_collision_baseline",
      "source_video": "scenes/twin_ramp_collision/cases/twin_ramp_collision_baseline/video.mp4",
      "edited_video": "scenes/twin_ramp_collision/cases/edit_remove_purple_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把紫色玻璃球从场景中删除。",
          "en": "From the start of the clip, remove the purple marble from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把紫色玻璃球从场景中删除。",
          "en": "From frame 1 onwards, remove the purple marble from the scene."
        }
      },
      "edit_dsl": "DELETE purple_ball",
      "edit_kind": "DELETE",
      "object_id": "purple_ball",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "purple_ball": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Purple marble removed. Same visible outcome as the grippy-purple edit -- yellow rolls into an empty valley alone, ending at x=+0.27 m at 0.52 m/s -- but reached through a completely different mechanism (the marble is simply not there rather than stuck at its ramp foot).",
      "ground_truth": "scenes/twin_ramp_collision/cases/edit_remove_purple_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/twin_ramp_collision/edit_remove_purple_ball.jpg"
    },
    {
      "global_id": "twin_ramp_collision/edit_remove_yellow_ball",
      "scene": "twin_ramp_collision",
      "case_id": "edit_remove_yellow_ball",
      "source_case_id": "twin_ramp_collision_baseline",
      "source_video": "scenes/twin_ramp_collision/cases/twin_ramp_collision_baseline/video.mp4",
      "edited_video": "scenes/twin_ramp_collision/cases/edit_remove_yellow_ball/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "从视频一开始,把黄色玻璃球从场景中删除。",
          "en": "From the start of the clip, remove the yellow marble from the scene."
        },
        "quantitative": {
          "zh": "从第 1 帧开始,把黄色玻璃球从场景中删除。",
          "en": "From frame 1 onwards, remove the yellow marble from the scene."
        }
      },
      "edit_dsl": "DELETE yellow_ball",
      "edit_kind": "DELETE",
      "object_id": "yellow_ball",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 1,
      "timing": "whole_clip",
      "physics_diff": {
        "yellow_ball": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 1,
          "total_frames": 96,
          "unedited_frames": []
        }
      },
      "edit_summary": "Yellow marble removed. Amber rolls unopposed the length of the plank and coasts past centre to x=-0.27 m, still doing 0.52 m/s. Mirror image of the remove-purple case on the opposite side of the valley.",
      "ground_truth": "scenes/twin_ramp_collision/cases/edit_remove_yellow_ball/ground_truth_transforms.json",
      "thumbnail": "thumbnails/twin_ramp_collision/edit_remove_yellow_ball.jpg"
    },
    {
      "global_id": "twin_ramp_collision/edit_remove_purple_ball_after_impact",
      "scene": "twin_ramp_collision",
      "case_id": "edit_remove_purple_ball_after_impact",
      "source_case_id": "twin_ramp_collision_baseline",
      "source_video": "scenes/twin_ramp_collision/cases/twin_ramp_collision_baseline/video.mp4",
      "edited_video": "scenes/twin_ramp_collision/cases/edit_remove_purple_ball_after_impact/video.mp4",
      "duration_sec": 4.0,
      "prompts": {
        "vague": {
          "zh": "在视频进行到一半左右时,把紫色玻璃球从场景中删除。",
          "en": "About halfway through the clip, remove the purple marble from the scene."
        },
        "quantitative": {
          "zh": "从第 39 帧开始,把紫色玻璃球从场景中删除。",
          "en": "From frame 39 onwards, remove the purple marble from the scene."
        }
      },
      "edit_dsl": "DELETE purple_ball AT FRAME 39",
      "edit_kind": "DELETE",
      "object_id": "purple_ball",
      "property": null,
      "outcome_type": "object_removed",
      "applies_from_frame": 39,
      "timing": "partway",
      "physics_diff": {
        "purple_ball": {
          "from": "present",
          "to": "removed"
        },
        "timing": {
          "applies_from_frame": 39,
          "total_frames": 96,
          "unedited_frames": [
            1,
            38
          ]
        }
      },
      "edit_summary": "Purple ball removed at frame 39, four frames after the two balls meet in the valley at frame 35. Frames 1-38 are the source video frame for frame, the head-on collision included: both balls roll down their ramps at 0.82 m/s, bounce off each other and are left creeping. Purple then disappears from x=+0.11 and yellow drifts on alone to x=+0.02. The whole-clip version of the same delete is a different video again: with no purple ball to meet, yellow crosses the whole valley and runs up the far ramp.",
      "ground_truth": "scenes/twin_ramp_collision/cases/edit_remove_purple_ball_after_impact/ground_truth_transforms.json",
      "thumbnail": "thumbnails/twin_ramp_collision/edit_remove_purple_ball_after_impact.jpg"
    }
  ]
}