diff --git a/.gitattributes b/.gitattributes
index 8f891cdf0fb1a4f0d4e539c6b84985ddaac952ed..440f31578cd454521bad1181a4caa649e13568cf 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -833,3 +833,4 @@ sessions/session_20260921_232822_920324/preprocessing/c6a-input-preparation-v1/n
 sessions/session_20260921_232822_920324/preprocessing/c6a-input-preparation-v1/native/appearance_train_v1/input_case/session_20260921_232822_920324/points3D.ply filter=lfs diff=lfs merge=lfs -text
 sessions/session_20260921_232822_920324/preprocessing/c6a-input-preparation-v1/native/appearance_train_v1/model/point_cloud/iteration_10000/point_cloud.ply filter=lfs diff=lfs merge=lfs -text
 sessions/session_20260921_232822_920324/preprocessing/c6a-input-preparation-v1/native/appearance_train_v1/model/point_cloud/iteration_7000/point_cloud.ply filter=lfs diff=lfs merge=lfs -text
+sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/rerun/appearance_spline_prior.rrd filter=lfs diff=lfs merge=lfs -text
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/colors/color_summary.json b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/colors/color_summary.json
new file mode 100644
index 0000000000000000000000000000000000000000..7bfa7d4a5d2e93d586bc94a69116fc857a19f048
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/colors/color_summary.json
@@ -0,0 +1,49 @@
+{
+  "rule": "native sRGB/255, cosine weighted over mask/depth/first-hit visible views",
+  "two_sided": true,
+  "depth_tolerance_m": 0.025,
+  "first_hit_tolerance_m": 0.0002,
+  "per_view": [
+    {
+      "view": 0,
+      "serial": "12540311",
+      "observed_vertices": 326,
+      "projected_inside": 450,
+      "first_hit": 373
+    },
+    {
+      "view": 1,
+      "serial": "12933256",
+      "observed_vertices": 282,
+      "projected_inside": 450,
+      "first_hit": 364
+    },
+    {
+      "view": 2,
+      "serial": "17736741",
+      "observed_vertices": 356,
+      "projected_inside": 450,
+      "first_hit": 378
+    },
+    {
+      "view": 3,
+      "serial": "23007103",
+      "observed_vertices": 326,
+      "projected_inside": 450,
+      "first_hit": 359
+    }
+  ],
+  "observed_vertices": 429,
+  "filled_vertices": 21,
+  "fill_color_rgb": [
+    0.39903542870848213,
+    0.34509803921568627,
+    0.30103847127459266
+  ],
+  "glb_roundtrip": {
+    "float32_positions_exact": true,
+    "vertex_colors_exact": true,
+    "uv_count": 0,
+    "vertex_reordered_on_open3d_load": true
+  }
+}
\ No newline at end of file
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/colors/vertex_colors.npz b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/colors/vertex_colors.npz
new file mode 100644
index 0000000000000000000000000000000000000000..cfc83123535923ef91cc1d7365473a3bebabc90c
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/colors/vertex_colors.npz
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:17ce02d91ae5881b0bdad15c0a05a7b989ee109e6e0997f50df50dbcfb900394
+size 15432
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/hybrid/populations.npz b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/hybrid/populations.npz
new file mode 100644
index 0000000000000000000000000000000000000000..62b12845e286c16656997062c2e210bc806f6191
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/hybrid/populations.npz
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2c485024f39174c98aa20f6f12f319bcccc4e7c52d7df8e965c81e310fb038e1
+size 2809454
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/inputs/depth_offset_diagnostic.json b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/inputs/depth_offset_diagnostic.json
new file mode 100644
index 0000000000000000000000000000000000000000..ea91556461573872a962a3f76ff6875367626e30
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/inputs/depth_offset_diagnostic.json
@@ -0,0 +1,90 @@
+{
+  "annulus_px": [
+    20,
+    80
+  ],
+  "interior_erosion_px": 2,
+  "correction_applied": false,
+  "views": [
+    {
+      "view": 0,
+      "serial": "12540311",
+      "annulus_count": 92945,
+      "belt_interior_count": 9854,
+      "belt_edge_count": 3737,
+      "table_median_z_m": -0.00012401869970213308,
+      "belt_interior_median_z_m": 0.01609010255783655,
+      "belt_edge_median_z_m": 0.003271125842275402,
+      "belt_minus_table_m": 0.016214121257538683,
+      "edge_minus_table_m": 0.003395144541977535,
+      "table_p10_p90_z_m": [
+        -0.0014471232353370444,
+        0.0012156596444444334
+      ],
+      "belt_interior_p10_p90_z_m": [
+        0.0027749029582622158,
+        0.024782165044356055
+      ]
+    },
+    {
+      "view": 1,
+      "serial": "12933256",
+      "annulus_count": 68085,
+      "belt_interior_count": 13360,
+      "belt_edge_count": 2890,
+      "table_median_z_m": -0.0005058559128141571,
+      "belt_interior_median_z_m": 0.010782964501522052,
+      "belt_edge_median_z_m": 0.0018792346830429074,
+      "belt_minus_table_m": 0.01128882041433621,
+      "edge_minus_table_m": 0.0023850905958570645,
+      "table_p10_p90_z_m": [
+        -0.0015711710766116438,
+        0.00013449394315021566
+      ],
+      "belt_interior_p10_p90_z_m": [
+        0.0011192199028891795,
+        0.02001653895829152
+      ]
+    },
+    {
+      "view": 2,
+      "serial": "17736741",
+      "annulus_count": 94359,
+      "belt_interior_count": 10651,
+      "belt_edge_count": 4224,
+      "table_median_z_m": 0.0020539015180771614,
+      "belt_interior_median_z_m": 0.015270963048751196,
+      "belt_edge_median_z_m": 0.004238497013420661,
+      "belt_minus_table_m": 0.013217061530674035,
+      "edge_minus_table_m": 0.0021845954953435,
+      "table_p10_p90_z_m": [
+        0.0002601132932266604,
+        0.0038094762192912857
+      ],
+      "belt_interior_p10_p90_z_m": [
+        0.003211016521765697,
+        0.023222516826146622
+      ]
+    },
+    {
+      "view": 3,
+      "serial": "23007103",
+      "annulus_count": 61323,
+      "belt_interior_count": 9886,
+      "belt_edge_count": 2904,
+      "table_median_z_m": -0.00023979439225108035,
+      "belt_interior_median_z_m": 0.013846420800038783,
+      "belt_edge_median_z_m": 0.0024474589598028618,
+      "belt_minus_table_m": 0.014086215192289864,
+      "edge_minus_table_m": 0.002687253352053942,
+      "table_p10_p90_z_m": [
+        -0.0017447719571583864,
+        0.00024240730059925665
+      ],
+      "belt_interior_p10_p90_z_m": [
+        0.0043789848153975575,
+        0.022200709962195142
+      ]
+    }
+  ]
+}
\ No newline at end of file
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/inputs/observed_cloud.npz b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/inputs/observed_cloud.npz
new file mode 100644
index 0000000000000000000000000000000000000000..3c4e33c3c521d5403ccf3bebbc5da9e234954541
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/inputs/observed_cloud.npz
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1f8d4283cb7cca51355433490faa124ae2b993d896ba744c5d38551094df395a
+size 3047188
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/inputs/reference_views.json b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/inputs/reference_views.json
new file mode 100644
index 0000000000000000000000000000000000000000..e2473250e52768faa92016f45716a1fa4d3cc68e
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/inputs/reference_views.json
@@ -0,0 +1,100 @@
+{
+  "case": "session_20260921_232822_920324",
+  "grid_sample": 0,
+  "views": [
+    {
+      "index": 0,
+      "serial": "12540311",
+      "native_frame": 0,
+      "offset_ms": 14.115702,
+      "object_mask_px": 13591,
+      "invalid_depth_in_mask_px": 0,
+      "occlusion_union_px": 132804,
+      "object_and_union_px": 0,
+      "lifted_points": 9620,
+      "lifted_z_min_max_m": [
+        -0.0023284568863624067,
+        0.030775777860925224
+      ],
+      "uneroded_lifted_points": 13591,
+      "uneroded_lifted_z_min_max_m": [
+        -0.0027910377797614183,
+        0.033030069574933485
+      ],
+      "eroded_lifted_points": 9854,
+      "erosion_removed_points": 3737,
+      "outlier_removed_points": 234
+    },
+    {
+      "index": 1,
+      "serial": "12933256",
+      "native_frame": 0,
+      "offset_ms": 9.747829,
+      "object_mask_px": 16250,
+      "invalid_depth_in_mask_px": 0,
+      "occlusion_union_px": 154087,
+      "object_and_union_px": 0,
+      "lifted_points": 13090,
+      "lifted_z_min_max_m": [
+        -0.002801856618944276,
+        0.026847888060681613
+      ],
+      "uneroded_lifted_points": 16250,
+      "uneroded_lifted_z_min_max_m": [
+        -0.004181857039834647,
+        0.0658507626346585
+      ],
+      "eroded_lifted_points": 13360,
+      "erosion_removed_points": 2890,
+      "outlier_removed_points": 270
+    },
+    {
+      "index": 2,
+      "serial": "17736741",
+      "native_frame": 0,
+      "offset_ms": 3.26476,
+      "object_mask_px": 14875,
+      "invalid_depth_in_mask_px": 0,
+      "occlusion_union_px": 191232,
+      "object_and_union_px": 0,
+      "lifted_points": 10056,
+      "lifted_z_min_max_m": [
+        -0.0009281391361578573,
+        0.033362889615193514
+      ],
+      "uneroded_lifted_points": 14875,
+      "uneroded_lifted_z_min_max_m": [
+        -0.003730801897673608,
+        0.03483003928452533
+      ],
+      "eroded_lifted_points": 10651,
+      "erosion_removed_points": 4224,
+      "outlier_removed_points": 595
+    },
+    {
+      "index": 3,
+      "serial": "23007103",
+      "native_frame": 0,
+      "offset_ms": 0.0,
+      "object_mask_px": 12790,
+      "invalid_depth_in_mask_px": 0,
+      "occlusion_union_px": 143608,
+      "object_and_union_px": 0,
+      "lifted_points": 9537,
+      "lifted_z_min_max_m": [
+        -0.0023284850348738173,
+        0.02761780733439978
+      ],
+      "uneroded_lifted_points": 12790,
+      "uneroded_lifted_z_min_max_m": [
+        -0.004463492111132172,
+        0.02901916985910713
+      ],
+      "eroded_lifted_points": 9886,
+      "erosion_removed_points": 2904,
+      "outlier_removed_points": 349
+    }
+  ],
+  "observed_points": 42303,
+  "mask_erosion_px": 2
+}
\ No newline at end of file
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/manifest.json b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/manifest.json
new file mode 100644
index 0000000000000000000000000000000000000000..4e43bf11905e31cc317c23fef2f39aff2da761b5
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/manifest.json
@@ -0,0 +1,1037 @@
+{
+  "kind": "real_rgbd_appearance_spline_prior_v1",
+  "code": {
+    "commit": "d1d2f1381470138dfbb3c58d448e53bfed1e0d7e",
+    "u_pin": "81c718790a37e5e0102eb77af2c6edd34a9db25f"
+  },
+  "steps": {
+    "colors": {
+      "status": "ok",
+      "settings": {
+        "depth_tolerance_m": 0.025
+      },
+      "outputs": {
+        "rule": "native sRGB/255, cosine weighted over mask/depth/first-hit visible views",
+        "two_sided": true,
+        "depth_tolerance_m": 0.025,
+        "first_hit_tolerance_m": 0.0002,
+        "per_view": [
+          {
+            "view": 0,
+            "serial": "12540311",
+            "observed_vertices": 326,
+            "projected_inside": 450,
+            "first_hit": 373
+          },
+          {
+            "view": 1,
+            "serial": "12933256",
+            "observed_vertices": 282,
+            "projected_inside": 450,
+            "first_hit": 364
+          },
+          {
+            "view": 2,
+            "serial": "17736741",
+            "observed_vertices": 356,
+            "projected_inside": 450,
+            "first_hit": 378
+          },
+          {
+            "view": 3,
+            "serial": "23007103",
+            "observed_vertices": 326,
+            "projected_inside": 450,
+            "first_hit": 359
+          }
+        ],
+        "observed_vertices": 429,
+        "filled_vertices": 21,
+        "fill_color_rgb": [
+          0.39903542870848213,
+          0.34509803921568627,
+          0.30103847127459266
+        ],
+        "glb_roundtrip": {
+          "float32_positions_exact": true,
+          "vertex_colors_exact": true,
+          "uv_count": 0,
+          "vertex_reordered_on_open3d_load": true
+        },
+        "files": {
+          "colors/vertex_colors.npz": "17ce02d91ae5881b0bdad15c0a05a7b989ee109e6e0997f50df50dbcfb900394",
+          "colors/color_summary.json": "fed1171e29c916eda9b57ea27365aae9ab1637a1f031adb876295b774125211a",
+          "ribbon/shape_prior.glb": "0b2c30e43fe3c27022b0737fc9553f38481d0f46e79a59e33b5b604e160b54a9",
+          "ribbon/ribbon.ply": "0e7fa61e37913d5c88e5d4104c1887e3804bbefb31739f954d6a92562954b9e6",
+          "gaussian_data/session_20260921_232822_920324/shape_prior.glb": "0b2c30e43fe3c27022b0737fc9553f38481d0f46e79a59e33b5b604e160b54a9"
+        }
+      },
+      "code": {
+        "commit": "d1d2f1381470138dfbb3c58d448e53bfed1e0d7e",
+        "u_pin": "81c718790a37e5e0102eb77af2c6edd34a9db25f"
+      },
+      "wall_time_s": 1.1682415008544922
+    },
+    "diagnose-depth": {
+      "status": "ok",
+      "settings": {
+        "correction": "none",
+        "annulus_px": [
+          20,
+          80
+        ]
+      },
+      "outputs": {
+        "report": {
+          "annulus_px": [
+            20,
+            80
+          ],
+          "interior_erosion_px": 2,
+          "correction_applied": false,
+          "views": [
+            {
+              "view": 0,
+              "serial": "12540311",
+              "annulus_count": 92945,
+              "belt_interior_count": 9854,
+              "belt_edge_count": 3737,
+              "table_median_z_m": -0.00012401869970213308,
+              "belt_interior_median_z_m": 0.01609010255783655,
+              "belt_edge_median_z_m": 0.003271125842275402,
+              "belt_minus_table_m": 0.016214121257538683,
+              "edge_minus_table_m": 0.003395144541977535,
+              "table_p10_p90_z_m": [
+                -0.0014471232353370444,
+                0.0012156596444444334
+              ],
+              "belt_interior_p10_p90_z_m": [
+                0.0027749029582622158,
+                0.024782165044356055
+              ]
+            },
+            {
+              "view": 1,
+              "serial": "12933256",
+              "annulus_count": 68085,
+              "belt_interior_count": 13360,
+              "belt_edge_count": 2890,
+              "table_median_z_m": -0.0005058559128141571,
+              "belt_interior_median_z_m": 0.010782964501522052,
+              "belt_edge_median_z_m": 0.0018792346830429074,
+              "belt_minus_table_m": 0.01128882041433621,
+              "edge_minus_table_m": 0.0023850905958570645,
+              "table_p10_p90_z_m": [
+                -0.0015711710766116438,
+                0.00013449394315021566
+              ],
+              "belt_interior_p10_p90_z_m": [
+                0.0011192199028891795,
+                0.02001653895829152
+              ]
+            },
+            {
+              "view": 2,
+              "serial": "17736741",
+              "annulus_count": 94359,
+              "belt_interior_count": 10651,
+              "belt_edge_count": 4224,
+              "table_median_z_m": 0.0020539015180771614,
+              "belt_interior_median_z_m": 0.015270963048751196,
+              "belt_edge_median_z_m": 0.004238497013420661,
+              "belt_minus_table_m": 0.013217061530674035,
+              "edge_minus_table_m": 0.0021845954953435,
+              "table_p10_p90_z_m": [
+                0.0002601132932266604,
+                0.0038094762192912857
+              ],
+              "belt_interior_p10_p90_z_m": [
+                0.003211016521765697,
+                0.023222516826146622
+              ]
+            },
+            {
+              "view": 3,
+              "serial": "23007103",
+              "annulus_count": 61323,
+              "belt_interior_count": 9886,
+              "belt_edge_count": 2904,
+              "table_median_z_m": -0.00023979439225108035,
+              "belt_interior_median_z_m": 0.013846420800038783,
+              "belt_edge_median_z_m": 0.0024474589598028618,
+              "belt_minus_table_m": 0.014086215192289864,
+              "edge_minus_table_m": 0.002687253352053942,
+              "table_p10_p90_z_m": [
+                -0.0017447719571583864,
+                0.00024240730059925665
+              ],
+              "belt_interior_p10_p90_z_m": [
+                0.0043789848153975575,
+                0.022200709962195142
+              ]
+            }
+          ]
+        },
+        "files": {
+          "inputs/depth_offset_diagnostic.json": "d9cdc492ac7eb84213e65463c1f446b92f5a596d453dcf9d8ca50228740e375c"
+        }
+      },
+      "code": {
+        "commit": "d1d2f1381470138dfbb3c58d448e53bfed1e0d7e",
+        "u_pin": "81c718790a37e5e0102eb77af2c6edd34a9db25f"
+      },
+      "wall_time_s": 0.3071320056915283
+    },
+    "fit": {
+      "status": "ok",
+      "settings": {
+        "object": {
+          "name": "grey_timing_belt",
+          "representation": "ribbon",
+          "fitter_source": "spline_estimation.timing_belt_fitting (scratch/test_timing_belt_perception.py)",
+          "dimension_source": "demonstrated 25 mm width; surface only, no interior (corpus Q1, 2026-10-25)",
+          "radius_m": null,
+          "ribbon_width_m": 0.025,
+          "step_t": 0.1,
+          "step_angle_deg": null,
+          "u_resolution": 5,
+          "overlap_rule": null,
+          "twist_penalty": {
+            "samples": 250,
+            "threshold_per_m": 10.0,
+            "huber_per_m": 30.0,
+            "cap_per_m": 80.0,
+            "weight": 5e-08
+          }
+        },
+        "max_rounds": 400,
+        "control_count": 9,
+        "relative_loss_tolerance": 1e-07,
+        "reprojection": {
+          "weight": 4.0,
+          "direction": "visible mask pixels to projected centerline",
+          "ribbon_twist_stage": "two-sided (owner Q11): visible mask pixels to projected width segments plus visible projected surface samples (off the occlusion union) to the nearest mask pixel",
+          "mask": "accepted object outside hand/occluder union",
+          "view_aggregation": "equal view means",
+          "distance": "metric image plane using per-view median visible belt depth and fx/fy",
+          "samples": 360,
+          "huber_delta_m": 0.005,
+          "smooth_cap_m": 0.035,
+          "baseline_run": null
+        },
+        "loss_config": {
+          "eval_distances": true,
+          "max_saturation_distance": 0.035,
+          "distance_huber_delta": 0.005,
+          "eval_curvature_cost": true,
+          "num_eval_reg_points": 250,
+          "lambda_curvature_cost": 5e-08,
+          "max_curvature": 10.0,
+          "curvature_huber_delta": 30.0,
+          "max_saturation_curvature": 80.0,
+          "eval_curvilinear_energy": false,
+          "lambda_curvilinear_energy": 0.001,
+          "eval_length_constraint": true,
+          "lambda_length_constraint": 0.1,
+          "arclength_bounds": [
+            0.6639999747276306,
+            0.6660000085830688
+          ]
+        },
+        "solver_config": {
+          "solver_type": "lbfgs",
+          "linesearch_type": "zoom",
+          "max_linesearch_steps": 10,
+          "grad_norm_tolerance": 0.0003,
+          "max_iter": 25
+        },
+        "ribbon_twist_refinement": {
+          "stage": "2 of 2; centerline control points frozen at stage 1, nine raw twist knots free",
+          "start": "stage-1 knots reduced modulo pi to bounded twist in (-pi/2, pi/2]",
+          "loss": "3D ribbon distance + weight x two-sided surface mask term + twist penalty",
+          "twist_penalty": {
+            "samples": 250,
+            "threshold_per_m": 10.0,
+            "huber_per_m": 30.0,
+            "cap_per_m": 80.0,
+            "weight": 5e-08
+          },
+          "solver": "SciPy L-BFGS-B, knots within +-pi*atanh(0.8) (twist within +-0.8 pi); objective / start value; ftol 1e-7 (the stage-1 relative rule), gtol 1e-12, maxls 20, maxiter = rounds x 25"
+        }
+      },
+      "outputs": {
+        "filter": {
+          "method": "Open3D.remove_statistical_outlier",
+          "nb_neighbors": 20,
+          "std_ratio": 2.0,
+          "input_count": 43751,
+          "kept_count": 42303,
+          "removed_count": 1448,
+          "per_view": [
+            {
+              "view": 0,
+              "input": 9854,
+              "kept": 9620,
+              "removed": 234,
+              "live_20_0.05_kept": 5139,
+              "no_filter_kept": 9854
+            },
+            {
+              "view": 1,
+              "input": 13360,
+              "kept": 13090,
+              "removed": 270,
+              "live_20_0.05_kept": 10166,
+              "no_filter_kept": 13360
+            },
+            {
+              "view": 2,
+              "input": 10651,
+              "kept": 10056,
+              "removed": 595,
+              "live_20_0.05_kept": 6501,
+              "no_filter_kept": 10651
+            },
+            {
+              "view": 3,
+              "input": 9886,
+              "kept": 9537,
+              "removed": 349,
+              "live_20_0.05_kept": 3829,
+              "no_filter_kept": 9886
+            }
+          ]
+        },
+        "rounds": 1,
+        "stop": "gradient_tolerance",
+        "final": {
+          "loss": 1.1125985110993497e-05,
+          "components": {
+            "distance": 6.239377853489714e-06,
+            "curvature": 2.9662308165256945e-08,
+            "arclength": 0.0,
+            "mask_reprojection_2d": 4.85694454255281e-06,
+            "twist": 0.0
+          },
+          "grad_norm": 1.2239328839314112e-07,
+          "arclength_m": 0.6656367182731628,
+          "arclength_bound_active_within_1mm": true,
+          "max_curvature_per_m": 13.758085250854492,
+          "curvature_p50_p90_per_m": [
+            9.229823112487793,
+            12.103294563293456
+          ],
+          "curvature_above_max_fraction": 0.436,
+          "mean_distance_m": 0.002945967965755432,
+          "max_distance_m": 0.012138253077864647,
+          "beyond_2delta_fraction": 0.002907595206013758,
+          "at_cap_fraction": 0.0,
+          "per_view": [
+            {
+              "view": 0,
+              "count": 9620,
+              "median_m": 0.002955671981908381,
+              "p90_m": 0.005897692404687405,
+              "max_m": 0.011453804560005665,
+              "beyond_2delta_fraction": 0.0008316008316008316,
+              "at_cap_fraction": 0.0
+            },
+            {
+              "view": 1,
+              "count": 13090,
+              "median_m": 0.001527400512713939,
+              "p90_m": 0.004019656637683512,
+              "max_m": 0.009406793862581253,
+              "beyond_2delta_fraction": 0.0,
+              "at_cap_fraction": 0.0
+            },
+            {
+              "view": 2,
+              "count": 10056,
+              "median_m": 0.0025791332591325045,
+              "p90_m": 0.005575997522100806,
+              "max_m": 0.012138253077864647,
+              "beyond_2delta_fraction": 0.004972155926809865,
+              "at_cap_fraction": 0.0
+            },
+            {
+              "view": 3,
+              "count": 9537,
+              "median_m": 0.004207869991660118,
+              "p90_m": 0.007775616366416216,
+              "max_m": 0.011057930067181587,
+              "beyond_2delta_fraction": 0.0068155604487784415,
+              "at_cap_fraction": 0.0
+            }
+          ],
+          "ribbon": {
+            "width_m": 0.02500000037252903,
+            "twist_rate_p90_max_per_m": [
+              1.877037727832794,
+              2.204266309738159
+            ],
+            "theta_at_knots_rad": [
+              -0.050911322236061096,
+              0.00613745441660285,
+              0.015087069943547249,
+              0.0699172168970108,
+              0.035111889243125916,
+              -0.015670809894800186,
+              -0.06571356952190399,
+              0.06471092998981476,
+              -0.06536029279232025
+            ],
+            "theta_min_max_rad": [
+              -0.08313477039337158,
+              0.07077524065971375
+            ],
+            "width_direction_abs_z_mean": 0.9957530638183941,
+            "closest_u_abs_mean": 0.5233570038025349,
+            "closest_u_at_width_edge_fraction": 0.09751081483582724
+          },
+          "raw_theta": [
+            -0.050800264598333755,
+            0.024028226939905944,
+            -0.008487866880423573,
+            0.10044636320053478,
+            0.02627501243083818,
+            0.00513371669847655,
+            -0.14083554530808823,
+            0.16386948166639043,
+            -0.12632189421484072
+          ]
+        },
+        "deterministic": true,
+        "partial_view_witness": {
+          "source": "synthetic upright elliptical band, four retained RP2 camera centres, both faces",
+          "seed": 6,
+          "noise_sigma_m": 0.0015,
+          "points": 288,
+          "ribbon_width_m": 0.025,
+          "truth_arclength_m": 0.664979607632856,
+          "fit_arclength_m": 0.6637027263641357,
+          "mean_point_to_ribbon_m": 0.0013682314893230796,
+          "mean_centerline_distance_to_truth_m": 0.0006032002581246964,
+          "max_centerline_distance_to_truth_m": 0.0015572715588724547,
+          "width_direction_abs_z_mean": 0.9987051767368632,
+          "width_direction_abs_z_min": 0.9958782713543136,
+          "theta_min_max_rad": [
+            -0.0679638460278511,
+            0.07198633253574371
+          ],
+          "rounds": 1,
+          "stop": "gradient_tolerance",
+          "twist_iterations": 12,
+          "twist_stop": "CONVERGENCE: RELATIVE REDUCTION OF F <= FACTR*EPSMCH"
+        },
+        "stage1_final": {
+          "loss": 5.64063957426697e-05,
+          "components": {
+            "distance": 6.267603566811886e-06,
+            "curvature": 2.9662308165256945e-08,
+            "arclength": 0.0,
+            "mask_reprojection_2d": 5.0109130825148895e-05
+          },
+          "grad_norm": 0.00020523875718936324,
+          "arclength_m": 0.6656367182731628,
+          "arclength_bound_active_within_1mm": true,
+          "max_curvature_per_m": 13.758085250854492,
+          "curvature_p50_p90_per_m": [
+            9.229823112487793,
+            12.103294563293456
+          ],
+          "curvature_above_max_fraction": 0.436,
+          "mean_distance_m": 0.0029467170108525634,
+          "max_distance_m": 0.012048400938510895,
+          "beyond_2delta_fraction": 0.002813039264354774,
+          "at_cap_fraction": 0.0,
+          "per_view": [
+            {
+              "view": 0,
+              "count": 9620,
+              "median_m": 0.002988048829138279,
+              "p90_m": 0.00560659090988338,
+              "max_m": 0.011225677095353603,
+              "beyond_2delta_fraction": 0.0007276507276507277,
+              "at_cap_fraction": 0.0
+            },
+            {
+              "view": 1,
+              "count": 13090,
+              "median_m": 0.001513904018793255,
+              "p90_m": 0.004024862358346582,
+              "max_m": 0.009322958998382092,
+              "beyond_2delta_fraction": 0.0,
+              "at_cap_fraction": 0.0
+            },
+            {
+              "view": 2,
+              "count": 10056,
+              "median_m": 0.0024846148444339633,
+              "p90_m": 0.005472885211929679,
+              "max_m": 0.012048400938510895,
+              "beyond_2delta_fraction": 0.004077167859984089,
+              "at_cap_fraction": 0.0
+            },
+            {
+              "view": 3,
+              "count": 9537,
+              "median_m": 0.004310430493205786,
+              "p90_m": 0.008035261370241641,
+              "max_m": 0.011003976687788963,
+              "beyond_2delta_fraction": 0.00744468910558876,
+              "at_cap_fraction": 0.0
+            }
+          ],
+          "ribbon": {
+            "width_m": 0.02500000037252903,
+            "twist_rate_p90_max_per_m": [
+              0.00018442391738062724,
+              0.00019782820891123265
+            ],
+            "theta_at_knots_rad": [
+              -7.558267043350497e-06,
+              -5.4865431593498215e-06,
+              -3.0992846404842567e-06,
+              8.272872946690768e-06,
+              1.7767291865311563e-05,
+              1.7871505406219512e-05,
+              1.688728661974892e-05,
+              1.0882817150559276e-05,
+              -3.7029883515060646e-06
+            ],
+            "theta_min_max_rad": [
+              -7.652295607840642e-06,
+              1.8543687474448234e-05
+            ],
+            "width_direction_abs_z_mean": 0.9968580948098288,
+            "closest_u_abs_mean": 0.5230010878438688,
+            "closest_u_at_width_edge_fraction": 0.09663617237548164
+          },
+          "round": 1,
+          "relative_loss_change": 0.9868065337776762
+        },
+        "twist": {
+          "start_raw_theta": [
+            -8.449404049335864e-06,
+            -4.698768862002774e-06,
+            -5.67477763980313e-06,
+            8.80217066880989e-06,
+            2.0103338101814704e-05,
+            1.738822538750454e-05,
+            1.757278914734104e-05,
+            1.3644331375048138e-05,
+            -6.8532140176211684e-06
+          ],
+          "start_loss": 1.132844317908166e-05,
+          "bound_raw": 3.451392295223203,
+          "knots_at_bound": 0,
+          "iterations": 10,
+          "evaluations": 65,
+          "stop": "CONVERGENCE: RELATIVE REDUCTION OF F <= FACTR*EPSMCH",
+          "success": true
+        },
+        "files": {
+          "spline/reprojection_residuals.npz": "6072f02f25a27a5f8f5a6958385ac1eb54cf979809355a03f1a7c106cd575e25",
+          "spline/residuals.npz": "d559753ccddd835a0f240373df0b5afc5091da496eaf1685d89b7cd74e6a42de",
+          "spline/filtered_cloud.npz": "79969ed1420c084352424b29f38c643e47f8caae3974f51f57a484323d29585c",
+          "spline/spline_init.json": "dc31754bbd876c342009fffb0eebdc9ad15b9876cd2c91c7fe1b01da16c10c09",
+          "spline/determinism.json": "e5ed40ea623c8519288ce80b1c86a50778bc2a4ba34bcb965ece98912a11c354",
+          "spline/filter.json": "0f253e135e5b5b5fb8ac4c07ab1c4134c7b36bbcd96845deb943c5c7fcefdf8c",
+          "spline/witness.json": "7b8b69d19e90d19bc910732039cb9c9bf51ad01e75ac47a45a8eda09dd361392",
+          "spline/filter_removed.npz": "a734dac86512a99159188400663e843df59fa953d397db5ce94f7ee634229676",
+          "spline/spline_stage1.json": "f5cc846bb0aab2a61a78bfd5e126554b155320c7834855c097071b887b621142",
+          "spline/twist_trajectory.jsonl": "f3f4872928559906ad045e1d400058230ebd15357a39fee755f54a4b685acfc5",
+          "spline/spline_fit.json": "ff195005d62377bdfb215a588bb3502a7d86c95f5df6fdda46bfae48f9dfad8e",
+          "spline/rounds.jsonl": "cd0991b45876158f5f1ca334fc3f94c9c0a978fbc6b9e8af25e4e0e763b65df9",
+          "spline/init_ellipse.json": "ec1efab4e2826e9a945cbcdb7525b9c42b724b08feaba31f250d4ca5afdb6a99",
+          "spline/reprojection.json": "9863c1ef13a69bb686626bd72cd426617c64be8a1433a0c680250de0c2d109c0"
+        }
+      },
+      "code": {
+        "commit": "d1d2f1381470138dfbb3c58d448e53bfed1e0d7e",
+        "u_pin": "81c718790a37e5e0102eb77af2c6edd34a9db25f"
+      },
+      "wall_time_s": 63.767921924591064
+    },
+    "hybrid": {
+      "status": "ok",
+      "settings": {
+        "u_pin": "81c718790a37e5e0102eb77af2c6edd34a9db25f",
+        "numpy_seed": 0,
+        "points_per_triangle": 30
+      },
+      "outputs": {
+        "counts": {
+          "observed": 42303,
+          "mesh": 21600,
+          "total": 63903,
+          "mesh_to_observed": 0.5106020849585136
+        },
+        "files": {
+          "hybrid/populations.npz": "2c485024f39174c98aa20f6f12f319bcccc4e7c52d7df8e965c81e310fb038e1"
+        }
+      },
+      "code": {
+        "commit": "d1d2f1381470138dfbb3c58d448e53bfed1e0d7e",
+        "u_pin": "81c718790a37e5e0102eb77af2c6edd34a9db25f"
+      },
+      "wall_time_s": 0.8447673320770264
+    },
+    "inputs": {
+      "status": "ok",
+      "settings": {
+        "object": "grey_timing_belt",
+        "depth_source": "waft_stereo_dav2l5",
+        "depth_stream_ids": [
+          "zed_12540311_depth_waft_stereo_synlarge_dav2l5_zdepth",
+          "zed_12933256_depth_waft_stereo_synlarge_dav2l5_zdepth",
+          "zed_17736741_depth_waft_stereo_synlarge_dav2l5_zdepth",
+          "zed_23007103_depth_waft_stereo_synlarge_dav2l5_zdepth"
+        ],
+        "frames": "/mnt/data2/magna/belt_perception_shared/phystwin_model_corpus_expansion/lab/session_20260921_232822_920324/window_anchor0331-0765/accepted_input_preparation_c6a_v1/frames_waft/per_camera_inputs.json",
+        "frames_sha256": "26bea474ca8e5350b648271f6119ab15a49dd2dec0deab6ee0e02b68beaaab2d",
+        "signed_native_frames_sha256": {
+          "12540311": "c8f6e415a7c80eb2337286753c3eccbac1a14a0d47ef5c60b704a6572829591d",
+          "12933256": "ca5a4cf4579162018ca1ae52ee347895e489c3d4a0ff8884c2cc19167ee61433",
+          "17736741": "4c1bd82f8c534880acb9718fe5636f1513133c6ddd785d212c6eea46a16aa2ea",
+          "23007103": "64329f6d79e5be632d63e9c344cb345363d0aaa401138fd4153d65c3be533cc6"
+        },
+        "camera_frames_sha256": {
+          "12540311": "f8d57f463997df49ef7e011a8fd946c33e18b9569eb79481baeec6a07014f8b6",
+          "12933256": "ba25acf17d91ccb96c6a756756645ba01dddfdd543f117e4baeeadbd56cfbefb",
+          "17736741": "ecaac0cf787955ca796b1975f65941b1e44456635340aed0470ad007f8bd8d7e",
+          "23007103": "7dc9ea608f94f716c08ab664b65211ea5a1f8a96b91564f246a8ee1d56aa43c5"
+        },
+        "mask_erosion_px": 2,
+        "filter": {
+          "method": "Open3D.remove_statistical_outlier",
+          "nb_neighbors": 20,
+          "std_ratio": 2.0,
+          "input_count": 43751,
+          "kept_count": 42303,
+          "removed_count": 1448,
+          "per_view": [
+            {
+              "view": 0,
+              "input": 9854,
+              "kept": 9620,
+              "removed": 234,
+              "live_20_0.05_kept": 5139,
+              "no_filter_kept": 9854
+            },
+            {
+              "view": 1,
+              "input": 13360,
+              "kept": 13090,
+              "removed": 270,
+              "live_20_0.05_kept": 10166,
+              "no_filter_kept": 13360
+            },
+            {
+              "view": 2,
+              "input": 10651,
+              "kept": 10056,
+              "removed": 595,
+              "live_20_0.05_kept": 6501,
+              "no_filter_kept": 10651
+            },
+            {
+              "view": 3,
+              "input": 9886,
+              "kept": 9537,
+              "removed": 349,
+              "live_20_0.05_kept": 3829,
+              "no_filter_kept": 9886
+            }
+          ]
+        },
+        "parent": null,
+        "unfitted_inputs": true,
+        "fitting_bundle_sha256": "9dc6b7b274ebe0c7eca27e807e4ed9b9802c3908e1f98fd4141d7d57bc1b5589",
+        "signoffs": {
+          "/mnt/data2/magna/belt_perception_shared/phystwin_model_corpus_expansion/lab/session_20260921_232822_920324/window_anchor0331-0765/native_inputs/cameras/12540311/review_signoff.json": "834f0909f06fb9ce3bbd633dd0cf58c1de1b42765adb0c8f2fe31e2aaf6c7657",
+          "/mnt/data2/magna/belt_perception_shared/phystwin_model_corpus_expansion/lab/session_20260921_232822_920324/window_anchor0331-0765/native_inputs/cameras/12540311/review_signoff_occluder.json": "d0ca49613b8a6831c7143eb668485804675c4ef5078f4ac777dd06b5a35568bf",
+          "/mnt/data2/magna/belt_perception_shared/phystwin_model_corpus_expansion/lab/session_20260921_232822_920324/window_anchor0331-0765/native_inputs/cameras/12933256/review_signoff.json": "c4c27ad9b5ea736a9b526a21b0a14fa663f365feaa61ed89d5585f7380a3b998",
+          "/mnt/data2/magna/belt_perception_shared/phystwin_model_corpus_expansion/lab/session_20260921_232822_920324/window_anchor0331-0765/native_inputs/cameras/12933256/review_signoff_occluder.json": "560dfd4076c288c592813dd16696abe557eb65e6390b1c164a1a16c94e7cb9db",
+          "/mnt/data2/magna/belt_perception_shared/phystwin_model_corpus_expansion/lab/session_20260921_232822_920324/window_anchor0331-0765/native_inputs/cameras/17736741/review_signoff.json": "cffdb40eb24e55165d81938f177f213bc81f1480f2d1a8b7a5d5378279b71bcc",
+          "/mnt/data2/magna/belt_perception_shared/phystwin_model_corpus_expansion/lab/session_20260921_232822_920324/window_anchor0331-0765/native_inputs/cameras/17736741/review_signoff_occluder.json": "fd555c92ed1c73ad00bf7673e6baca7c05333cc14be8409eae479ee3a1ead3ff",
+          "/mnt/data2/magna/belt_perception_shared/phystwin_model_corpus_expansion/lab/session_20260921_232822_920324/window_anchor0331-0765/native_inputs/cameras/23007103/review_signoff.json": "ded6d0307b35c4604ae20921df17d2e0bc49b88bf0a6094825e272a4c9cf8582",
+          "/mnt/data2/magna/belt_perception_shared/phystwin_model_corpus_expansion/lab/session_20260921_232822_920324/window_anchor0331-0765/native_inputs/cameras/23007103/review_signoff_occluder.json": "9618440a92373d6c45dbd90dee078a9191e5b1254deb2b2c4473cd995ac62a83"
+        }
+      },
+      "outputs": {
+        "reference": {
+          "case": "session_20260921_232822_920324",
+          "grid_sample": 0,
+          "views": [
+            {
+              "index": 0,
+              "serial": "12540311",
+              "native_frame": 0,
+              "offset_ms": 14.115702,
+              "object_mask_px": 13591,
+              "invalid_depth_in_mask_px": 0,
+              "occlusion_union_px": 132804,
+              "object_and_union_px": 0,
+              "lifted_points": 9620,
+              "lifted_z_min_max_m": [
+                -0.0023284568863624067,
+                0.030775777860925224
+              ],
+              "uneroded_lifted_points": 13591,
+              "uneroded_lifted_z_min_max_m": [
+                -0.0027910377797614183,
+                0.033030069574933485
+              ],
+              "eroded_lifted_points": 9854,
+              "erosion_removed_points": 3737,
+              "outlier_removed_points": 234
+            },
+            {
+              "index": 1,
+              "serial": "12933256",
+              "native_frame": 0,
+              "offset_ms": 9.747829,
+              "object_mask_px": 16250,
+              "invalid_depth_in_mask_px": 0,
+              "occlusion_union_px": 154087,
+              "object_and_union_px": 0,
+              "lifted_points": 13090,
+              "lifted_z_min_max_m": [
+                -0.002801856618944276,
+                0.026847888060681613
+              ],
+              "uneroded_lifted_points": 16250,
+              "uneroded_lifted_z_min_max_m": [
+                -0.004181857039834647,
+                0.0658507626346585
+              ],
+              "eroded_lifted_points": 13360,
+              "erosion_removed_points": 2890,
+              "outlier_removed_points": 270
+            },
+            {
+              "index": 2,
+              "serial": "17736741",
+              "native_frame": 0,
+              "offset_ms": 3.26476,
+              "object_mask_px": 14875,
+              "invalid_depth_in_mask_px": 0,
+              "occlusion_union_px": 191232,
+              "object_and_union_px": 0,
+              "lifted_points": 10056,
+              "lifted_z_min_max_m": [
+                -0.0009281391361578573,
+                0.033362889615193514
+              ],
+              "uneroded_lifted_points": 14875,
+              "uneroded_lifted_z_min_max_m": [
+                -0.003730801897673608,
+                0.03483003928452533
+              ],
+              "eroded_lifted_points": 10651,
+              "erosion_removed_points": 4224,
+              "outlier_removed_points": 595
+            },
+            {
+              "index": 3,
+              "serial": "23007103",
+              "native_frame": 0,
+              "offset_ms": 0.0,
+              "object_mask_px": 12790,
+              "invalid_depth_in_mask_px": 0,
+              "occlusion_union_px": 143608,
+              "object_and_union_px": 0,
+              "lifted_points": 9537,
+              "lifted_z_min_max_m": [
+                -0.0023284850348738173,
+                0.02761780733439978
+              ],
+              "uneroded_lifted_points": 12790,
+              "uneroded_lifted_z_min_max_m": [
+                -0.004463492111132172,
+                0.02901916985910713
+              ],
+              "eroded_lifted_points": 9886,
+              "erosion_removed_points": 2904,
+              "outlier_removed_points": 349
+            }
+          ],
+          "observed_points": 42303,
+          "mask_erosion_px": 2
+        },
+        "files": {
+          "inputs/observed_cloud.npz": "1f8d4283cb7cca51355433490faa124ae2b993d896ba744c5d38551094df395a",
+          "inputs/reference_views.json": "e9a79e571a910ac8a9d7715434dd96207b7f3c4925b7adf0935f7c0eebb3ec2c",
+          "gaussian_data/session_20260921_232822_920324/0.png": "5fefb36318cab8ef184e4da60e609a87ace523121600c79901e59790d5acc98a",
+          "gaussian_data/session_20260921_232822_920324/mask_0.png": "6bd219bf2827a0c92f14ec547ab937d348245965cfeecdc99270f9dee7e8376b",
+          "gaussian_data/session_20260921_232822_920324/mask_human_0.png": "f7ba4bb6d4946a01f42b610c450188a9b619987e2cbbf115fe40285ae6ad1458",
+          "gaussian_data/session_20260921_232822_920324/0_depth.npy": "9c85d347cb09fe3ff2ff5504244188893394a4eb5f160e67a58d0395fcf3e2a0",
+          "gaussian_data/session_20260921_232822_920324/1.png": "e18d763cc5fc528dd31e061b68ac2512645ef60fb997a35d70880ea8f5209ba6",
+          "gaussian_data/session_20260921_232822_920324/mask_1.png": "c93d3c0079fda0a84bf7a650673bea0182a00607c231c813d66414166f7eca48",
+          "gaussian_data/session_20260921_232822_920324/mask_human_1.png": "af8097e786cd1ee341b5420f30991e2f0f4570b255a9c6fbd9298bd0bf0eb7ef",
+          "gaussian_data/session_20260921_232822_920324/1_depth.npy": "db673693ca01bcd4909243de7bcae165fcf4a5578dadb3c8969492fc8f9f724b",
+          "gaussian_data/session_20260921_232822_920324/2.png": "ac26a550aced8911edc02f18300c1a5715f8886c8528081191a010da26f2664d",
+          "gaussian_data/session_20260921_232822_920324/mask_2.png": "fb98637c06a056622d0c90b1fd7d89861a832720cefedfb78af816c15756d4ec",
+          "gaussian_data/session_20260921_232822_920324/mask_human_2.png": "3d37f8d46e6be2d409133a55a54b519b500f632e6f2ccec593efc64d55257f57",
+          "gaussian_data/session_20260921_232822_920324/2_depth.npy": "9165a02dd2adbac976a53ef9f5fdb5846fde9817de58ce01efd8825447ef0487",
+          "gaussian_data/session_20260921_232822_920324/3.png": "61fbe1aa6b28b3741994a1bd38bd4233725f5b7a4643de73411a7c70ee7a93c1",
+          "gaussian_data/session_20260921_232822_920324/mask_3.png": "080b6403f066b73b03d015bc510d6e0b75625523572e4c0d30a7153c1587c3c7",
+          "gaussian_data/session_20260921_232822_920324/mask_human_3.png": "129c10fe7c602811fea7f514bf1111e51a5c0bcb5e97360accb204204b56fd53",
+          "gaussian_data/session_20260921_232822_920324/3_depth.npy": "96067a19a8e8763259dbb1ad0d3be8bac73d138c5a5c9e69028dab038a2eefff",
+          "gaussian_data/session_20260921_232822_920324/camera_meta.pkl": "3e88eba07fa7a1c6aac0e3fdcc97b3228d69ea9eca593f11b9cb927a6990d31b",
+          "gaussian_data/session_20260921_232822_920324/interp_poses.pkl": "b90cc26123c822f0d06446ac699e110db22a86e265c56751819029a46f558b6f",
+          "gaussian_data/session_20260921_232822_920324/observation.ply": "158e3efd97ba375d9d3a7f994e162f9331a7eb828de848647984bdfc59c9772f",
+          "spline/filter.json": "0f253e135e5b5b5fb8ac4c07ab1c4134c7b36bbcd96845deb943c5c7fcefdf8c",
+          "spline/filter_removed.npz": "a734dac86512a99159188400663e843df59fa953d397db5ce94f7ee634229676",
+          "spline/filtered_cloud.npz": "79969ed1420c084352424b29f38c643e47f8caae3974f51f57a484323d29585c"
+        }
+      },
+      "code": {
+        "commit": "d1d2f1381470138dfbb3c58d448e53bfed1e0d7e",
+        "u_pin": "81c718790a37e5e0102eb77af2c6edd34a9db25f"
+      },
+      "wall_time_s": 31.35102105140686
+    },
+    "review": {
+      "status": "ok",
+      "settings": {
+        "historical_prior": null,
+        "historical_sha256": null,
+        "baseline_fit": null
+      },
+      "outputs": {
+        "review_files": 53,
+        "files": {
+          "review/hybrid/combined.png": "694dd87c293b1eece55eae152a4dd5af91883b7cf46ad5cc7b4d3b1c7bda5a04",
+          "review/hybrid/mesh.png": "4a8f1a3080ef140962eac3e2faaf3fcb7c33462e830a92cb4251dfec2fd5048b",
+          "review/hybrid/observed.png": "2c646e585e86d442eef7afb40e9c28682c495f3c16a83adcced5e72b1fdaa04a",
+          "review/inputs/depth_offset_table.json": "d9cdc492ac7eb84213e65463c1f446b92f5a596d453dcf9d8ca50228740e375c",
+          "review/inputs/depth_offset.png": "68f215008bf0af7fa5bba250e2ff0895562283e80177cb3270b4ff95e5da8a4e",
+          "review/inputs/view_3_23007103.png": "d05fb51d36021bd9587a793e993bd9f5bb6e808f9f6c6c4dd231b22f4742fb58",
+          "review/inputs/view_0_12540311.png": "cf7ac45a7ee18ca34b965169ea54af3df64b3d77334d027634050417ef6944d4",
+          "review/inputs/view_1_12933256.png": "0eccd5dc91d7276d5753840a0618ad0fa5b3e0363fb6e915b6c4eb2677450623",
+          "review/inputs/cloud_rgb.png": "9c7e4d338c31293db1f5eb86febf997eeb4c0a08e5798e7fc49e5f60c07f1634",
+          "review/inputs/filter_removed.png": "e98b02f48e248cf8f51da456b05b64a62c81b832bf833dc8af1cffe7f3075f47",
+          "review/inputs/cloud_by_view.png": "f480b013633a6c85ec810176c2345140dc458f740a755f6d578f75121b9e1f51",
+          "review/inputs/view_2_17736741.png": "acefe02a87c44ec58d44095cb0c74fcc344f56bca588e2523289179f63a4b75b",
+          "review/rerun/headless_contact_sheet.png": "8895d6944b109fede39103cbbfbbcd91acf785fc2b6d3c4cc7afb60f3a1b3bcc",
+          "review/spline/centerline_0_with_masks.png": "74f48ea3b29d297ac654bae0c820cbee8edc97885918e5fcae5434b0f168c399",
+          "review/spline/centerline_3_unmasked.png": "fd69b56dacd2636bed2506aea93beea11e064957fa0cd4038e8a5066d8209850",
+          "review/spline/per_view_arc_coverage.png": "a739551062d7841caf101cc8707d28d40fbc1e7808a318acf7577ae2bc28abea",
+          "review/spline/fit_projections.png": "34d8ed157a9c5e6ab1c3ec54244f2e9efc45cd175ff0c8fddd27f39a20cc735c",
+          "review/spline/centerline_1_unmasked.png": "1935ca6bd54172661246a7e685ea5a21ab76a97e2ab3723ac79ebc841ca6f412",
+          "review/spline/centerline_2_with_masks.png": "30ff90fb7dbc88b8c8f36c085c6da30069b39785531444b8c18a4c88b588c0ab",
+          "review/spline/centerline_1_with_masks.png": "95c77b22a1064bf5d7bc3f09615f930f50913d75f8dba56e24cd0b458338586d",
+          "review/spline/centerline_2_unmasked.png": "01fc324015ee92131d822d4c1102c759f41cb129c7f631ad4f34aed585271738",
+          "review/spline/round_curves.png": "feb7b67b19e86c8e48854ef9210043a5dc0e9fd4da70641db0dbc7a4a73fa5df",
+          "review/spline/curvature_profile.png": "0b42af8808b8a22ec2fca3d3f3508908aee61ab916595e097b674abb0d421f33",
+          "review/spline/residual_histograms.png": "6ce027c709d83858e2c6b6433ed15fb14d88ba0552115898a51b9edb0ff23c4a",
+          "review/spline/centerline_3_with_masks.png": "818d84a4655b66553b2cbcc5d7b1613d4bdb461486539912c0341be99e63441e",
+          "review/spline/fit_3d.png": "72e73b50e17cb72884d51f564e50f2bf3a31077dbf1c032cc696333925c4d513",
+          "review/spline/centerline_0_unmasked.png": "02faa6d839c10bfdfc784f6cc64a5a79471e5857295d5d396e1361951a8ff6d3",
+          "review/colors/fill_swatch.txt": "c3f8572cab9e2be4741966f9fbc6405ec5045095a90be396ef396c4e2f6b71f9",
+          "review/colors/view_2_visibility.png": "42c8407563d01818bdffaf601da408c68d232c37f98733d37d12738c0ddbaf64",
+          "review/colors/view_1_visibility.png": "5e48ad333c23cf2e0d00f3ed742c4597b40d33e89377c63d97bdf21cdef60dae",
+          "review/colors/visibility_and_fill.png": "814800221c88bcf2b41e4203dad0ff880742830fcd917eb746919d201a7a391f",
+          "review/colors/view_0_visibility.png": "f10e741dd79cb7d45734fb5bde5633cae75172030a913b76a2a47f5edada4f6f",
+          "review/colors/fill_swatch.png": "58164a5af51062d045d76400e85ad4e87cfa840c1aebcf563967be27fcac72ae",
+          "review/colors/view_3_visibility.png": "fa43aa594020af40c31d8f070e532e4808392ee672d26f25f8687389b39466d2",
+          "review/ribbon/silhouette_1_unmasked.png": "6ab8ec8a4464638e0e9d4fafa21dd2075cf89a4912f811d29a908be4921266e7",
+          "review/ribbon/silhouette_0_unmasked.png": "a7aa7d87d76ea030ca47b743e59c96f027748ec6cb2bc1566b6965f33565e408",
+          "review/ribbon/twist_and_width_direction.png": "70e388290a78b24dcfd749a402203de0b2451599517c42cbac1ad198b241d12b",
+          "review/ribbon/ribbon_profiles.png": "47f96f7475e7b7b831219417cea0f34570416d2bb42c50f6d0aa11e0bcfbd466",
+          "review/ribbon/ribbon_scale_views.png": "b768d9cdbb6ad4b142885ea7cb2fd73179d147591a150ea1958945cd143791c0",
+          "review/ribbon/silhouette_0_with_masks.png": "2107f3e3b3ef51c7af6fd075dfeb798e643826c24c6634cc05c651ef518a3f82",
+          "review/ribbon/silhouette_1_with_masks.png": "ff74f30b793bfa1ca13ede0f58d44a8e9e3531ba343b67e978791bc4ff5a2843",
+          "review/ribbon/silhouette_2_unmasked.png": "1e35410572d9763ae5f42f6ad1c94da0e8aa4e4c3c049a437f44d9867c104756",
+          "review/ribbon/silhouette_3_with_masks.png": "3e4afd357e896ce907fd9a6742b2b3784be43edcf0584f95c91e925f05a398b6",
+          "review/ribbon/silhouette_2_with_masks.png": "154f6c569edaa9992732c59334277e20940749622f28cf80beecb471762b9432",
+          "review/ribbon/check_table.json": "acb80125f8e0140f7a9d28f2f6b2907cc366e33c3b848ea3981888a3ec4df6f9",
+          "review/ribbon/orbit.mp4": "ebb641bfb0efa7c6199547886308ab819b28a4f39493254333c5a2647714f2e7",
+          "review/ribbon/silhouette_3_unmasked.png": "a537e926692e297ae162f4abb7bc7e2a87622abc298b875c2d6171b5b2505de4",
+          "rerun/appearance_spline_prior.rrd": "6f8ce5984afa19ce00d325c31ec6338353ea5d6cbc7ec8c609c5cf4efd4216a0"
+        }
+      },
+      "code": {
+        "commit": "d1d2f1381470138dfbb3c58d448e53bfed1e0d7e",
+        "u_pin": "81c718790a37e5e0102eb77af2c6edd34a9db25f"
+      },
+      "wall_time_s": 15.316488265991211
+    },
+    "ribbon": {
+      "status": "ok",
+      "settings": {
+        "width_m": 0.02500000037252903,
+        "step_t": 0.1,
+        "u_resolution": 5,
+        "interior": "none (owner surface-only route)"
+      },
+      "outputs": {
+        "checks": {
+          "representation": "zero-thickness intrinsic ribbon surface (open width edges)",
+          "euler_characteristic": 0,
+          "watertight": false,
+          "components": 1,
+          "winding_consistent": true,
+          "boundary_loop_edges": [
+            90,
+            90
+          ],
+          "degenerate_triangles": 0,
+          "open3d_reported_intersecting_pairs": 0,
+          "confirmed_intersecting_pairs": [],
+          "self_intersecting": false,
+          "maximum_width_error_m": 3.467930685674414e-09,
+          "maximum_midline_error_m": 3.736641687737786e-09,
+          "maximum_tangent_width_dot": 5.966961243546176e-07,
+          "seam_surface_error_m": 0.0,
+          "minimum_nonadjacent_centerline_distance_m": 0.013778813717554317,
+          "theta_min_max_rad": [
+            -0.08293568342924118,
+            0.0707787498831749
+          ],
+          "width_direction_abs_z_mean": 0.9957387096676589,
+          "triangle_area_m2": {
+            "min": 2.1185713303117386e-05,
+            "median": 2.260841702941023e-05,
+            "mean": 2.3108186075747983e-05,
+            "max": 2.601480649752073e-05,
+            "density_max_over_min": 1.2279410244682563
+          },
+          "bounds_m": [
+            [
+              -0.08502081036567688,
+              -0.2170107066631317,
+              -0.0029200988356024027
+            ],
+            [
+              0.14453162252902985,
+              -0.022457193583250046,
+              0.0244786124676466
+            ]
+          ],
+          "width_m": 0.02500000037252903,
+          "step_t": 0.1,
+          "u_resolution": 5,
+          "passed": true
+        },
+        "vertex_count": 450,
+        "triangle_count": 720,
+        "files": {
+          "ribbon/triangle_areas.npz": "1e597ea2c4995a567ec5e98acab6acf4775acf80c1f7bd6cb32e393333c0d4aa",
+          "ribbon/geometry.npz": "0e6d9e6c856a74a3b14a0748305b897b33315226c841951c8bb2e65b52af7fed",
+          "ribbon/ribbon_checks.json": "acb80125f8e0140f7a9d28f2f6b2907cc366e33c3b848ea3981888a3ec4df6f9"
+        }
+      },
+      "code": {
+        "commit": "d1d2f1381470138dfbb3c58d448e53bfed1e0d7e",
+        "u_pin": "81c718790a37e5e0102eb77af2c6edd34a9db25f"
+      },
+      "wall_time_s": 3.410750389099121
+    }
+  },
+  "files": {
+    "colors/color_summary.json": "fed1171e29c916eda9b57ea27365aae9ab1637a1f031adb876295b774125211a",
+    "colors/vertex_colors.npz": "17ce02d91ae5881b0bdad15c0a05a7b989ee109e6e0997f50df50dbcfb900394",
+    "gaussian_data/session_20260921_232822_920324/0.png": "5fefb36318cab8ef184e4da60e609a87ace523121600c79901e59790d5acc98a",
+    "gaussian_data/session_20260921_232822_920324/0_depth.npy": "9c85d347cb09fe3ff2ff5504244188893394a4eb5f160e67a58d0395fcf3e2a0",
+    "gaussian_data/session_20260921_232822_920324/1.png": "e18d763cc5fc528dd31e061b68ac2512645ef60fb997a35d70880ea8f5209ba6",
+    "gaussian_data/session_20260921_232822_920324/1_depth.npy": "db673693ca01bcd4909243de7bcae165fcf4a5578dadb3c8969492fc8f9f724b",
+    "gaussian_data/session_20260921_232822_920324/2.png": "ac26a550aced8911edc02f18300c1a5715f8886c8528081191a010da26f2664d",
+    "gaussian_data/session_20260921_232822_920324/2_depth.npy": "9165a02dd2adbac976a53ef9f5fdb5846fde9817de58ce01efd8825447ef0487",
+    "gaussian_data/session_20260921_232822_920324/3.png": "61fbe1aa6b28b3741994a1bd38bd4233725f5b7a4643de73411a7c70ee7a93c1",
+    "gaussian_data/session_20260921_232822_920324/3_depth.npy": "96067a19a8e8763259dbb1ad0d3be8bac73d138c5a5c9e69028dab038a2eefff",
+    "gaussian_data/session_20260921_232822_920324/camera_meta.pkl": "3e88eba07fa7a1c6aac0e3fdcc97b3228d69ea9eca593f11b9cb927a6990d31b",
+    "gaussian_data/session_20260921_232822_920324/interp_poses.pkl": "b90cc26123c822f0d06446ac699e110db22a86e265c56751819029a46f558b6f",
+    "gaussian_data/session_20260921_232822_920324/mask_0.png": "6bd219bf2827a0c92f14ec547ab937d348245965cfeecdc99270f9dee7e8376b",
+    "gaussian_data/session_20260921_232822_920324/mask_1.png": "c93d3c0079fda0a84bf7a650673bea0182a00607c231c813d66414166f7eca48",
+    "gaussian_data/session_20260921_232822_920324/mask_2.png": "fb98637c06a056622d0c90b1fd7d89861a832720cefedfb78af816c15756d4ec",
+    "gaussian_data/session_20260921_232822_920324/mask_3.png": "080b6403f066b73b03d015bc510d6e0b75625523572e4c0d30a7153c1587c3c7",
+    "gaussian_data/session_20260921_232822_920324/mask_human_0.png": "f7ba4bb6d4946a01f42b610c450188a9b619987e2cbbf115fe40285ae6ad1458",
+    "gaussian_data/session_20260921_232822_920324/mask_human_1.png": "af8097e786cd1ee341b5420f30991e2f0f4570b255a9c6fbd9298bd0bf0eb7ef",
+    "gaussian_data/session_20260921_232822_920324/mask_human_2.png": "3d37f8d46e6be2d409133a55a54b519b500f632e6f2ccec593efc64d55257f57",
+    "gaussian_data/session_20260921_232822_920324/mask_human_3.png": "129c10fe7c602811fea7f514bf1111e51a5c0bcb5e97360accb204204b56fd53",
+    "gaussian_data/session_20260921_232822_920324/observation.ply": "158e3efd97ba375d9d3a7f994e162f9331a7eb828de848647984bdfc59c9772f",
+    "gaussian_data/session_20260921_232822_920324/shape_prior.glb": "0b2c30e43fe3c27022b0737fc9553f38481d0f46e79a59e33b5b604e160b54a9",
+    "hybrid/populations.npz": "2c485024f39174c98aa20f6f12f319bcccc4e7c52d7df8e965c81e310fb038e1",
+    "inputs/depth_offset_diagnostic.json": "d9cdc492ac7eb84213e65463c1f446b92f5a596d453dcf9d8ca50228740e375c",
+    "inputs/observed_cloud.npz": "1f8d4283cb7cca51355433490faa124ae2b993d896ba744c5d38551094df395a",
+    "inputs/reference_views.json": "e9a79e571a910ac8a9d7715434dd96207b7f3c4925b7adf0935f7c0eebb3ec2c",
+    "rerun/appearance_spline_prior.rrd": "6f8ce5984afa19ce00d325c31ec6338353ea5d6cbc7ec8c609c5cf4efd4216a0",
+    "review/colors/fill_swatch.png": "58164a5af51062d045d76400e85ad4e87cfa840c1aebcf563967be27fcac72ae",
+    "review/colors/fill_swatch.txt": "c3f8572cab9e2be4741966f9fbc6405ec5045095a90be396ef396c4e2f6b71f9",
+    "review/colors/view_0_visibility.png": "f10e741dd79cb7d45734fb5bde5633cae75172030a913b76a2a47f5edada4f6f",
+    "review/colors/view_1_visibility.png": "5e48ad333c23cf2e0d00f3ed742c4597b40d33e89377c63d97bdf21cdef60dae",
+    "review/colors/view_2_visibility.png": "42c8407563d01818bdffaf601da408c68d232c37f98733d37d12738c0ddbaf64",
+    "review/colors/view_3_visibility.png": "fa43aa594020af40c31d8f070e532e4808392ee672d26f25f8687389b39466d2",
+    "review/colors/visibility_and_fill.png": "814800221c88bcf2b41e4203dad0ff880742830fcd917eb746919d201a7a391f",
+    "review/hybrid/combined.png": "694dd87c293b1eece55eae152a4dd5af91883b7cf46ad5cc7b4d3b1c7bda5a04",
+    "review/hybrid/mesh.png": "4a8f1a3080ef140962eac3e2faaf3fcb7c33462e830a92cb4251dfec2fd5048b",
+    "review/hybrid/observed.png": "2c646e585e86d442eef7afb40e9c28682c495f3c16a83adcced5e72b1fdaa04a",
+    "review/inputs/cloud_by_view.png": "f480b013633a6c85ec810176c2345140dc458f740a755f6d578f75121b9e1f51",
+    "review/inputs/cloud_rgb.png": "9c7e4d338c31293db1f5eb86febf997eeb4c0a08e5798e7fc49e5f60c07f1634",
+    "review/inputs/depth_offset.png": "68f215008bf0af7fa5bba250e2ff0895562283e80177cb3270b4ff95e5da8a4e",
+    "review/inputs/depth_offset_table.json": "d9cdc492ac7eb84213e65463c1f446b92f5a596d453dcf9d8ca50228740e375c",
+    "review/inputs/filter_removed.png": "e98b02f48e248cf8f51da456b05b64a62c81b832bf833dc8af1cffe7f3075f47",
+    "review/inputs/view_0_12540311.png": "cf7ac45a7ee18ca34b965169ea54af3df64b3d77334d027634050417ef6944d4",
+    "review/inputs/view_1_12933256.png": "0eccd5dc91d7276d5753840a0618ad0fa5b3e0363fb6e915b6c4eb2677450623",
+    "review/inputs/view_2_17736741.png": "acefe02a87c44ec58d44095cb0c74fcc344f56bca588e2523289179f63a4b75b",
+    "review/inputs/view_3_23007103.png": "d05fb51d36021bd9587a793e993bd9f5bb6e808f9f6c6c4dd231b22f4742fb58",
+    "review/rerun/headless_contact_sheet.png": "8895d6944b109fede39103cbbfbbcd91acf785fc2b6d3c4cc7afb60f3a1b3bcc",
+    "review/ribbon/check_table.json": "acb80125f8e0140f7a9d28f2f6b2907cc366e33c3b848ea3981888a3ec4df6f9",
+    "review/ribbon/orbit.mp4": "ebb641bfb0efa7c6199547886308ab819b28a4f39493254333c5a2647714f2e7",
+    "review/ribbon/ribbon_profiles.png": "47f96f7475e7b7b831219417cea0f34570416d2bb42c50f6d0aa11e0bcfbd466",
+    "review/ribbon/ribbon_scale_views.png": "b768d9cdbb6ad4b142885ea7cb2fd73179d147591a150ea1958945cd143791c0",
+    "review/ribbon/silhouette_0_unmasked.png": "a7aa7d87d76ea030ca47b743e59c96f027748ec6cb2bc1566b6965f33565e408",
+    "review/ribbon/silhouette_0_with_masks.png": "2107f3e3b3ef51c7af6fd075dfeb798e643826c24c6634cc05c651ef518a3f82",
+    "review/ribbon/silhouette_1_unmasked.png": "6ab8ec8a4464638e0e9d4fafa21dd2075cf89a4912f811d29a908be4921266e7",
+    "review/ribbon/silhouette_1_with_masks.png": "ff74f30b793bfa1ca13ede0f58d44a8e9e3531ba343b67e978791bc4ff5a2843",
+    "review/ribbon/silhouette_2_unmasked.png": "1e35410572d9763ae5f42f6ad1c94da0e8aa4e4c3c049a437f44d9867c104756",
+    "review/ribbon/silhouette_2_with_masks.png": "154f6c569edaa9992732c59334277e20940749622f28cf80beecb471762b9432",
+    "review/ribbon/silhouette_3_unmasked.png": "a537e926692e297ae162f4abb7bc7e2a87622abc298b875c2d6171b5b2505de4",
+    "review/ribbon/silhouette_3_with_masks.png": "3e4afd357e896ce907fd9a6742b2b3784be43edcf0584f95c91e925f05a398b6",
+    "review/ribbon/twist_and_width_direction.png": "70e388290a78b24dcfd749a402203de0b2451599517c42cbac1ad198b241d12b",
+    "review/spline/centerline_0_unmasked.png": "02faa6d839c10bfdfc784f6cc64a5a79471e5857295d5d396e1361951a8ff6d3",
+    "review/spline/centerline_0_with_masks.png": "74f48ea3b29d297ac654bae0c820cbee8edc97885918e5fcae5434b0f168c399",
+    "review/spline/centerline_1_unmasked.png": "1935ca6bd54172661246a7e685ea5a21ab76a97e2ab3723ac79ebc841ca6f412",
+    "review/spline/centerline_1_with_masks.png": "95c77b22a1064bf5d7bc3f09615f930f50913d75f8dba56e24cd0b458338586d",
+    "review/spline/centerline_2_unmasked.png": "01fc324015ee92131d822d4c1102c759f41cb129c7f631ad4f34aed585271738",
+    "review/spline/centerline_2_with_masks.png": "30ff90fb7dbc88b8c8f36c085c6da30069b39785531444b8c18a4c88b588c0ab",
+    "review/spline/centerline_3_unmasked.png": "fd69b56dacd2636bed2506aea93beea11e064957fa0cd4038e8a5066d8209850",
+    "review/spline/centerline_3_with_masks.png": "818d84a4655b66553b2cbcc5d7b1613d4bdb461486539912c0341be99e63441e",
+    "review/spline/curvature_profile.png": "0b42af8808b8a22ec2fca3d3f3508908aee61ab916595e097b674abb0d421f33",
+    "review/spline/fit_3d.png": "72e73b50e17cb72884d51f564e50f2bf3a31077dbf1c032cc696333925c4d513",
+    "review/spline/fit_projections.png": "34d8ed157a9c5e6ab1c3ec54244f2e9efc45cd175ff0c8fddd27f39a20cc735c",
+    "review/spline/per_view_arc_coverage.png": "a739551062d7841caf101cc8707d28d40fbc1e7808a318acf7577ae2bc28abea",
+    "review/spline/residual_histograms.png": "6ce027c709d83858e2c6b6433ed15fb14d88ba0552115898a51b9edb0ff23c4a",
+    "review/spline/round_curves.png": "feb7b67b19e86c8e48854ef9210043a5dc0e9fd4da70641db0dbc7a4a73fa5df",
+    "ribbon/geometry.npz": "0e6d9e6c856a74a3b14a0748305b897b33315226c841951c8bb2e65b52af7fed",
+    "ribbon/ribbon.ply": "0e7fa61e37913d5c88e5d4104c1887e3804bbefb31739f954d6a92562954b9e6",
+    "ribbon/ribbon_checks.json": "acb80125f8e0140f7a9d28f2f6b2907cc366e33c3b848ea3981888a3ec4df6f9",
+    "ribbon/shape_prior.glb": "0b2c30e43fe3c27022b0737fc9553f38481d0f46e79a59e33b5b604e160b54a9",
+    "ribbon/triangle_areas.npz": "1e597ea2c4995a567ec5e98acab6acf4775acf80c1f7bd6cb32e393333c0d4aa",
+    "spline/determinism.json": "e5ed40ea623c8519288ce80b1c86a50778bc2a4ba34bcb965ece98912a11c354",
+    "spline/filter.json": "0f253e135e5b5b5fb8ac4c07ab1c4134c7b36bbcd96845deb943c5c7fcefdf8c",
+    "spline/filter_removed.npz": "a734dac86512a99159188400663e843df59fa953d397db5ce94f7ee634229676",
+    "spline/filtered_cloud.npz": "79969ed1420c084352424b29f38c643e47f8caae3974f51f57a484323d29585c",
+    "spline/init_ellipse.json": "ec1efab4e2826e9a945cbcdb7525b9c42b724b08feaba31f250d4ca5afdb6a99",
+    "spline/reprojection.json": "9863c1ef13a69bb686626bd72cd426617c64be8a1433a0c680250de0c2d109c0",
+    "spline/reprojection_residuals.npz": "6072f02f25a27a5f8f5a6958385ac1eb54cf979809355a03f1a7c106cd575e25",
+    "spline/residuals.npz": "d559753ccddd835a0f240373df0b5afc5091da496eaf1685d89b7cd74e6a42de",
+    "spline/rounds.jsonl": "cd0991b45876158f5f1ca334fc3f94c9c0a978fbc6b9e8af25e4e0e763b65df9",
+    "spline/spline_fit.json": "ff195005d62377bdfb215a588bb3502a7d86c95f5df6fdda46bfae48f9dfad8e",
+    "spline/spline_init.json": "dc31754bbd876c342009fffb0eebdc9ad15b9876cd2c91c7fe1b01da16c10c09",
+    "spline/spline_stage1.json": "f5cc846bb0aab2a61a78bfd5e126554b155320c7834855c097071b887b621142",
+    "spline/twist_trajectory.jsonl": "f3f4872928559906ad045e1d400058230ebd15357a39fee755f54a4b685acfc5",
+    "spline/witness.json": "7b8b69d19e90d19bc910732039cb9c9bf51ad01e75ac47a45a8eda09dd361392",
+    "steps/colors.json": "18791367dfbcc62c0abbad5779cfcf5af0997894e26f1ba0f2e660cd82fa0812",
+    "steps/diagnose-depth.json": "0fe0d42a55e908c23682dc7851f2ce99b2c60d42682c1df98186b1e7fbda57d3",
+    "steps/fit.json": "955f7e2a794a615defc78ebb8a8b7c4039c19c6a016f6113576e3092471173a6",
+    "steps/hybrid.json": "7d4d543c2a53b4e9dd9aed0f9f68b9ec4615ab8ccf794ddaecbe359a89c55f81",
+    "steps/inputs.json": "4e2c9b7c10f464bec6c990a05e89f2c633f0db9a155c96b6e66475b36d7bf4a6",
+    "steps/review.json": "15851b4459e743ecd4ae3752db4b7be4eb71f3cd2c21798434a037655f516051",
+    "steps/ribbon.json": "6997b61b9571557cd3521cca714118726da8fe0971a835abfa7b6cfdc5c60c98"
+  }
+}
\ No newline at end of file
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/rerun/appearance_spline_prior.rrd b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/rerun/appearance_spline_prior.rrd
new file mode 100644
index 0000000000000000000000000000000000000000..127a7c852b0fae6ef9a23a670f0edc882f7f2232
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/rerun/appearance_spline_prior.rrd
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6f8ce5984afa19ce00d325c31ec6338353ea5d6cbc7ec8c609c5cf4efd4216a0
+size 25561407
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/colors/fill_swatch.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/colors/fill_swatch.png
new file mode 100644
index 0000000000000000000000000000000000000000..378518dd1b7c07be66d74ad87b4c4af2d55250ac
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/colors/fill_swatch.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:58164a5af51062d045d76400e85ad4e87cfa840c1aebcf563967be27fcac72ae
+size 393
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/colors/fill_swatch.txt b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/colors/fill_swatch.txt
new file mode 100644
index 0000000000000000000000000000000000000000..561efd1d081bc8adc355f3fd1589745dcf577c17
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/colors/fill_swatch.txt
@@ -0,0 +1,2 @@
+Per-channel median of 429 observed vertex colours (RGB/255): [0.39903542870848213, 0.34509803921568627, 0.30103847127459266]
+Filled 21 vertices.
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/colors/view_0_visibility.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/colors/view_0_visibility.png
new file mode 100644
index 0000000000000000000000000000000000000000..9998083e9b2d2d01f79d7a71310b0615fac24aae
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/colors/view_0_visibility.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f10e741dd79cb7d45734fb5bde5633cae75172030a913b76a2a47f5edada4f6f
+size 96057
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/colors/view_1_visibility.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/colors/view_1_visibility.png
new file mode 100644
index 0000000000000000000000000000000000000000..4e7181f34c2444a047ae33e23ad50f28a8205279
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/colors/view_1_visibility.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5e48ad333c23cf2e0d00f3ed742c4597b40d33e89377c63d97bdf21cdef60dae
+size 90260
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/colors/view_2_visibility.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/colors/view_2_visibility.png
new file mode 100644
index 0000000000000000000000000000000000000000..b4dc5a1a530687ae70f9f903e05b4afb914d0ef8
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/colors/view_2_visibility.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:42c8407563d01818bdffaf601da408c68d232c37f98733d37d12738c0ddbaf64
+size 98959
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/colors/view_3_visibility.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/colors/view_3_visibility.png
new file mode 100644
index 0000000000000000000000000000000000000000..336b2fb71528946d099ef4524ab7cb072fb9c9e4
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/colors/view_3_visibility.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fa43aa594020af40c31d8f070e532e4808392ee672d26f25f8687389b39466d2
+size 96425
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/colors/visibility_and_fill.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/colors/visibility_and_fill.png
new file mode 100644
index 0000000000000000000000000000000000000000..5eba8955b66a16c8fdc488a03f05e4d128062566
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/colors/visibility_and_fill.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:814800221c88bcf2b41e4203dad0ff880742830fcd917eb746919d201a7a391f
+size 103549
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/hybrid/combined.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/hybrid/combined.png
new file mode 100644
index 0000000000000000000000000000000000000000..0c32214e939d1c0d755bc13cefdffaad08ad7e99
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/hybrid/combined.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:694dd87c293b1eece55eae152a4dd5af91883b7cf46ad5cc7b4d3b1c7bda5a04
+size 233938
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/hybrid/mesh.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/hybrid/mesh.png
new file mode 100644
index 0000000000000000000000000000000000000000..c70d10592fab7f0aed0dce22db2462abb28a1931
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/hybrid/mesh.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4a8f1a3080ef140962eac3e2faaf3fcb7c33462e830a92cb4251dfec2fd5048b
+size 281069
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/hybrid/observed.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/hybrid/observed.png
new file mode 100644
index 0000000000000000000000000000000000000000..2d6e559296cd2d06d98a5fcd803df87323c31caa
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/hybrid/observed.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2c646e585e86d442eef7afb40e9c28682c495f3c16a83adcced5e72b1fdaa04a
+size 370421
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/cloud_by_view.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/cloud_by_view.png
new file mode 100644
index 0000000000000000000000000000000000000000..0d508dd8d3b72a22c33236ebea444b22dcc028f7
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/cloud_by_view.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f480b013633a6c85ec810176c2345140dc458f740a755f6d578f75121b9e1f51
+size 301623
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/cloud_rgb.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/cloud_rgb.png
new file mode 100644
index 0000000000000000000000000000000000000000..aff4fe0cfa36035845d3f064e5bdc56c9bf5c490
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/cloud_rgb.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9c7e4d338c31293db1f5eb86febf997eeb4c0a08e5798e7fc49e5f60c07f1634
+size 373731
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/depth_offset.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/depth_offset.png
new file mode 100644
index 0000000000000000000000000000000000000000..c2462ce74601743f1402d36ba6389260b3bfaa12
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/depth_offset.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:68f215008bf0af7fa5bba250e2ff0895562283e80177cb3270b4ff95e5da8a4e
+size 25966
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/filter_removed.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/filter_removed.png
new file mode 100644
index 0000000000000000000000000000000000000000..55492e9a032c1189033369470523ef4e9d671cc3
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/filter_removed.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e98b02f48e248cf8f51da456b05b64a62c81b832bf833dc8af1cffe7f3075f47
+size 222678
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/view_0_12540311.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/view_0_12540311.png
new file mode 100644
index 0000000000000000000000000000000000000000..ba9c9c56d44ea7d6ea68baf269a804f11a4ff5eb
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/view_0_12540311.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:cf7ac45a7ee18ca34b965169ea54af3df64b3d77334d027634050417ef6944d4
+size 902513
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/view_1_12933256.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/view_1_12933256.png
new file mode 100644
index 0000000000000000000000000000000000000000..48d846a62996f146a9a2e73de74c8427affef73b
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/view_1_12933256.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0eccd5dc91d7276d5753840a0618ad0fa5b3e0363fb6e915b6c4eb2677450623
+size 702009
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/view_2_17736741.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/view_2_17736741.png
new file mode 100644
index 0000000000000000000000000000000000000000..1773a5dc92497660d492ccd6f8867bd248ab81d9
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/view_2_17736741.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:acefe02a87c44ec58d44095cb0c74fcc344f56bca588e2523289179f63a4b75b
+size 936103
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/view_3_23007103.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/view_3_23007103.png
new file mode 100644
index 0000000000000000000000000000000000000000..68baa064cf67c9c389c933401e25d48f020919ad
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/inputs/view_3_23007103.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d05fb51d36021bd9587a793e993bd9f5bb6e808f9f6c6c4dd231b22f4742fb58
+size 646723
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/rerun/headless_contact_sheet.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/rerun/headless_contact_sheet.png
new file mode 100644
index 0000000000000000000000000000000000000000..2427b41d424c176f2aa018f9c3c0d687c70166e4
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/rerun/headless_contact_sheet.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8895d6944b109fede39103cbbfbbcd91acf785fc2b6d3c4cc7afb60f3a1b3bcc
+size 1193345
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/check_table.json b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/check_table.json
new file mode 100644
index 0000000000000000000000000000000000000000..75fbd46cfbe66f6a2ba9b1f5e01ce05a12ddafa2
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/check_table.json
@@ -0,0 +1,48 @@
+{
+  "representation": "zero-thickness intrinsic ribbon surface (open width edges)",
+  "euler_characteristic": 0,
+  "watertight": false,
+  "components": 1,
+  "winding_consistent": true,
+  "boundary_loop_edges": [
+    90,
+    90
+  ],
+  "degenerate_triangles": 0,
+  "open3d_reported_intersecting_pairs": 0,
+  "confirmed_intersecting_pairs": [],
+  "self_intersecting": false,
+  "maximum_width_error_m": 3.467930685674414e-09,
+  "maximum_midline_error_m": 3.736641687737786e-09,
+  "maximum_tangent_width_dot": 5.966961243546176e-07,
+  "seam_surface_error_m": 0.0,
+  "minimum_nonadjacent_centerline_distance_m": 0.013778813717554317,
+  "theta_min_max_rad": [
+    -0.08293568342924118,
+    0.0707787498831749
+  ],
+  "width_direction_abs_z_mean": 0.9957387096676589,
+  "triangle_area_m2": {
+    "min": 2.1185713303117386e-05,
+    "median": 2.260841702941023e-05,
+    "mean": 2.3108186075747983e-05,
+    "max": 2.601480649752073e-05,
+    "density_max_over_min": 1.2279410244682563
+  },
+  "bounds_m": [
+    [
+      -0.08502081036567688,
+      -0.2170107066631317,
+      -0.0029200988356024027
+    ],
+    [
+      0.14453162252902985,
+      -0.022457193583250046,
+      0.0244786124676466
+    ]
+  ],
+  "width_m": 0.02500000037252903,
+  "step_t": 0.1,
+  "u_resolution": 5,
+  "passed": true
+}
\ No newline at end of file
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/orbit.mp4 b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/orbit.mp4
new file mode 100644
index 0000000000000000000000000000000000000000..f4dcc0b608c5708f9f52acec68723357ccdc584c
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/orbit.mp4
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ebb641bfb0efa7c6199547886308ab819b28a4f39493254333c5a2647714f2e7
+size 987042
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/ribbon_profiles.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/ribbon_profiles.png
new file mode 100644
index 0000000000000000000000000000000000000000..2beeb52669b282618cc6d24ab4abe85e6aabbc29
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/ribbon_profiles.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:47f96f7475e7b7b831219417cea0f34570416d2bb42c50f6d0aa11e0bcfbd466
+size 269555
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/ribbon_scale_views.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/ribbon_scale_views.png
new file mode 100644
index 0000000000000000000000000000000000000000..18bd4c6b63a579f407d6bdaff30417f4bba761ef
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/ribbon_scale_views.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b768d9cdbb6ad4b142885ea7cb2fd73179d147591a150ea1958945cd143791c0
+size 221128
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_0_unmasked.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_0_unmasked.png
new file mode 100644
index 0000000000000000000000000000000000000000..ae132a81ebcc799d1e54b13282a5304227ad6b58
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_0_unmasked.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a7aa7d87d76ea030ca47b743e59c96f027748ec6cb2bc1566b6965f33565e408
+size 227754
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_0_with_masks.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_0_with_masks.png
new file mode 100644
index 0000000000000000000000000000000000000000..aef6650e50a5c76036f2fc687886c5d36c98d57d
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_0_with_masks.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2107f3e3b3ef51c7af6fd075dfeb798e643826c24c6634cc05c651ef518a3f82
+size 231205
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_1_unmasked.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_1_unmasked.png
new file mode 100644
index 0000000000000000000000000000000000000000..cbfb2db9617e4d630d485dec0bb93f25bf675d0e
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_1_unmasked.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6ab8ec8a4464638e0e9d4fafa21dd2075cf89a4912f811d29a908be4921266e7
+size 174301
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_1_with_masks.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_1_with_masks.png
new file mode 100644
index 0000000000000000000000000000000000000000..3becbccd901da49dfeb2c96d9ad49e0adf8a536d
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_1_with_masks.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ff74f30b793bfa1ca13ede0f58d44a8e9e3531ba343b67e978791bc4ff5a2843
+size 178043
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_2_unmasked.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_2_unmasked.png
new file mode 100644
index 0000000000000000000000000000000000000000..93a9adf547b13e4ad8db0e188c97e97efc03688e
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_2_unmasked.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1e35410572d9763ae5f42f6ad1c94da0e8aa4e4c3c049a437f44d9867c104756
+size 230136
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_2_with_masks.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_2_with_masks.png
new file mode 100644
index 0000000000000000000000000000000000000000..5fc1e2c28f2c6eeeda533ef99bbeb7c35828d452
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_2_with_masks.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:154f6c569edaa9992732c59334277e20940749622f28cf80beecb471762b9432
+size 238172
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_3_unmasked.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_3_unmasked.png
new file mode 100644
index 0000000000000000000000000000000000000000..2f6bd2ed150b5e1266dd194ee0cf073ca1379f9f
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_3_unmasked.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a537e926692e297ae162f4abb7bc7e2a87622abc298b875c2d6171b5b2505de4
+size 159059
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_3_with_masks.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_3_with_masks.png
new file mode 100644
index 0000000000000000000000000000000000000000..729530f839ee33285060f8613c43d197c2034ba8
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/silhouette_3_with_masks.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3e4afd357e896ce907fd9a6742b2b3784be43edcf0584f95c91e925f05a398b6
+size 163694
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/twist_and_width_direction.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/twist_and_width_direction.png
new file mode 100644
index 0000000000000000000000000000000000000000..7e0536635ef15553e7e6a268da098670f8d33ba7
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/ribbon/twist_and_width_direction.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:70e388290a78b24dcfd749a402203de0b2451599517c42cbac1ad198b241d12b
+size 106520
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_0_unmasked.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_0_unmasked.png
new file mode 100644
index 0000000000000000000000000000000000000000..a89ad4dc58ec511e209a4e32500c57bf24e335bb
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_0_unmasked.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:02faa6d839c10bfdfc784f6cc64a5a79471e5857295d5d396e1361951a8ff6d3
+size 234560
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_0_with_masks.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_0_with_masks.png
new file mode 100644
index 0000000000000000000000000000000000000000..00225fc2dfb061c5f2d96d99c11f98e45d8f0702
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_0_with_masks.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:74f48ea3b29d297ac654bae0c820cbee8edc97885918e5fcae5434b0f168c399
+size 232792
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_1_unmasked.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_1_unmasked.png
new file mode 100644
index 0000000000000000000000000000000000000000..25f41734b6f082363714a6f914329d366a088c7a
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_1_unmasked.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1935ca6bd54172661246a7e685ea5a21ab76a97e2ab3723ac79ebc841ca6f412
+size 182173
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_1_with_masks.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_1_with_masks.png
new file mode 100644
index 0000000000000000000000000000000000000000..c9742d52a1f31777c4f425983872194de643a920
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_1_with_masks.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:95c77b22a1064bf5d7bc3f09615f930f50913d75f8dba56e24cd0b458338586d
+size 179320
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_2_unmasked.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_2_unmasked.png
new file mode 100644
index 0000000000000000000000000000000000000000..82f65f97dceeb606d2dc6874c23b91ab12668c5f
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_2_unmasked.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:01fc324015ee92131d822d4c1102c759f41cb129c7f631ad4f34aed585271738
+size 241386
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_2_with_masks.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_2_with_masks.png
new file mode 100644
index 0000000000000000000000000000000000000000..9f7ca55708c9440e8ce49e81743879dd22bbd665
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_2_with_masks.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:30ff90fb7dbc88b8c8f36c085c6da30069b39785531444b8c18a4c88b588c0ab
+size 241195
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_3_unmasked.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_3_unmasked.png
new file mode 100644
index 0000000000000000000000000000000000000000..592b1af94f999c65ebbcdc7654654217aafde571
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_3_unmasked.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fd69b56dacd2636bed2506aea93beea11e064957fa0cd4038e8a5066d8209850
+size 165998
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_3_with_masks.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_3_with_masks.png
new file mode 100644
index 0000000000000000000000000000000000000000..ab0f3c5ea38f2f4210eff0af5218b3c7e69cdab2
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/centerline_3_with_masks.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:818d84a4655b66553b2cbcc5d7b1613d4bdb461486539912c0341be99e63441e
+size 164440
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/curvature_profile.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/curvature_profile.png
new file mode 100644
index 0000000000000000000000000000000000000000..f816a136603538152a31a10a5be1577e84224cbc
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/curvature_profile.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0b42af8808b8a22ec2fca3d3f3508908aee61ab916595e097b674abb0d421f33
+size 46247
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/fit_3d.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/fit_3d.png
new file mode 100644
index 0000000000000000000000000000000000000000..995a78956837b9a23e8db01c9055bcd452ab33b9
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/fit_3d.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:72e73b50e17cb72884d51f564e50f2bf3a31077dbf1c032cc696333925c4d513
+size 386878
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/fit_projections.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/fit_projections.png
new file mode 100644
index 0000000000000000000000000000000000000000..f77e731d03ea09b964001367c79b05dd65d16d77
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/fit_projections.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:34d8ed157a9c5e6ab1c3ec54244f2e9efc45cd175ff0c8fddd27f39a20cc735c
+size 164506
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/per_view_arc_coverage.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/per_view_arc_coverage.png
new file mode 100644
index 0000000000000000000000000000000000000000..a283c55fa29bac06ea0611b5478b7240f82b3084
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/per_view_arc_coverage.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a739551062d7841caf101cc8707d28d40fbc1e7808a318acf7577ae2bc28abea
+size 40050
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/residual_histograms.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/residual_histograms.png
new file mode 100644
index 0000000000000000000000000000000000000000..cfa01a1faefedcfc3625a03308cc327d522e2fb6
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/residual_histograms.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6ce027c709d83858e2c6b6433ed15fb14d88ba0552115898a51b9edb0ff23c4a
+size 56438
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/round_curves.png b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/round_curves.png
new file mode 100644
index 0000000000000000000000000000000000000000..633d84436401816b385862f9d8ac34d3daba27fd
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/review/spline/round_curves.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:feb7b67b19e86c8e48854ef9210043a5dc0e9fd4da70641db0dbc7a4a73fa5df
+size 64801
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/ribbon/geometry.npz b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/ribbon/geometry.npz
new file mode 100644
index 0000000000000000000000000000000000000000..5a28da6e73a513ae193b0669190762f55f021215
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/ribbon/geometry.npz
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0e6d9e6c856a74a3b14a0748305b897b33315226c841951c8bb2e65b52af7fed
+size 49232
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/ribbon/ribbon.ply b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/ribbon/ribbon.ply
new file mode 100644
index 0000000000000000000000000000000000000000..c84f9ab3754172373b5bcfaf9fc03d4b09a0ec6d
Binary files /dev/null and b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/ribbon/ribbon.ply differ
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/ribbon/triangle_areas.npz b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/ribbon/triangle_areas.npz
new file mode 100644
index 0000000000000000000000000000000000000000..b854e7a0a6a643d8a0b6438663b4e003baf5b3da
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/ribbon/triangle_areas.npz
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1e597ea2c4995a567ec5e98acab6acf4775acf80c1f7bd6cb32e393333c0d4aa
+size 6028
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/filter.json b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/filter.json
new file mode 100644
index 0000000000000000000000000000000000000000..fed4fd7e8f6b27072e728e0edfb3091bc9e87ce7
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/filter.json
@@ -0,0 +1,42 @@
+{
+  "method": "Open3D.remove_statistical_outlier",
+  "nb_neighbors": 20,
+  "std_ratio": 2.0,
+  "input_count": 43751,
+  "kept_count": 42303,
+  "removed_count": 1448,
+  "per_view": [
+    {
+      "view": 0,
+      "input": 9854,
+      "kept": 9620,
+      "removed": 234,
+      "live_20_0.05_kept": 5139,
+      "no_filter_kept": 9854
+    },
+    {
+      "view": 1,
+      "input": 13360,
+      "kept": 13090,
+      "removed": 270,
+      "live_20_0.05_kept": 10166,
+      "no_filter_kept": 13360
+    },
+    {
+      "view": 2,
+      "input": 10651,
+      "kept": 10056,
+      "removed": 595,
+      "live_20_0.05_kept": 6501,
+      "no_filter_kept": 10651
+    },
+    {
+      "view": 3,
+      "input": 9886,
+      "kept": 9537,
+      "removed": 349,
+      "live_20_0.05_kept": 3829,
+      "no_filter_kept": 9886
+    }
+  ]
+}
\ No newline at end of file
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/filter_removed.npz b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/filter_removed.npz
new file mode 100644
index 0000000000000000000000000000000000000000..2cfee351887ec6103807e3f38b09d8d0b94e874b
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/filter_removed.npz
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a734dac86512a99159188400663e843df59fa953d397db5ce94f7ee634229676
+size 117094
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/filtered_cloud.npz b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/filtered_cloud.npz
new file mode 100644
index 0000000000000000000000000000000000000000..50b91ef1717ae49baa6998d4dfd372f6e79c40e8
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/filtered_cloud.npz
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:79969ed1420c084352424b29f38c643e47f8caae3974f51f57a484323d29585c
+size 3046814
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/init_ellipse.json b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/init_ellipse.json
new file mode 100644
index 0000000000000000000000000000000000000000..2a47dd112f5071b0311ee41294d7ec4342675273
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/init_ellipse.json
@@ -0,0 +1,27 @@
+{
+  "center_m": [
+    0.021922958745781256,
+    -0.12870191750607435,
+    0.013258731618951154
+  ],
+  "semi_axes_m": [
+    0.07976489494811856,
+    0.06901654587456255
+  ],
+  "directions": [
+    [
+      0.834988070704329,
+      -0.5502608033084767
+    ],
+    [
+      -0.5502516777044871,
+      -0.834991816029179
+    ],
+    [
+      -0.0042441683354518586,
+      -0.001309773493291483
+    ]
+  ],
+  "points_used": 42303,
+  "ellipse_fit_points": 1000
+}
\ No newline at end of file
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/reprojection.json b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/reprojection.json
new file mode 100644
index 0000000000000000000000000000000000000000..2736dac0363e2fc5271d8e376b4aa666093dfa97
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/reprojection.json
@@ -0,0 +1,71 @@
+{
+  "samples": 360,
+  "direction": "visible mask pixels to projected ribbon width segments",
+  "per_view": [
+    {
+      "view": 0,
+      "serial": "12540311",
+      "mask_pixels": 13591,
+      "median_depth_m": 1.143,
+      "mean_m": 0.0006363390310538933,
+      "median_m": 0.000459731050381479,
+      "p90_m": 0.0013781487821463328,
+      "mean_px": 0.8382481334162746,
+      "median_px": 0.6056057011683145,
+      "p90_px": 1.8154451686089563,
+      "visible_surface_samples": 1576,
+      "outside_mask_fraction": 0.02918781725888325,
+      "surface_to_mask_mean_px": 0.04009408876299858,
+      "surface_to_mask_p90_px": 0.0
+    },
+    {
+      "view": 1,
+      "serial": "12933256",
+      "mask_pixels": 16250,
+      "median_depth_m": 1.097,
+      "mean_m": 0.0004712305635660849,
+      "median_m": 0.0003890152704632225,
+      "p90_m": 0.0008215802152423164,
+      "mean_px": 0.6379419679391852,
+      "median_px": 0.5266446314374816,
+      "p90_px": 1.1122491880640366,
+      "visible_surface_samples": 1522,
+      "outside_mask_fraction": 0.05387647831800263,
+      "surface_to_mask_mean_px": 1.2044357061386108,
+      "surface_to_mask_p90_px": 0.0
+    },
+    {
+      "view": 2,
+      "serial": "17736741",
+      "mask_pixels": 14875,
+      "median_depth_m": 1.135,
+      "mean_m": 0.0007748616841210794,
+      "median_m": 0.0004809680183615069,
+      "p90_m": 0.0020058882253194635,
+      "mean_px": 1.030227770248317,
+      "median_px": 0.6394796352745942,
+      "p90_px": 2.6669700164306467,
+      "visible_surface_samples": 1779,
+      "outside_mask_fraction": 0.023608768971332208,
+      "surface_to_mask_mean_px": 0.030180975794792175,
+      "surface_to_mask_p90_px": 0.0
+    },
+    {
+      "view": 3,
+      "serial": "23007103",
+      "mask_pixels": 12790,
+      "median_depth_m": 0.933,
+      "mean_m": 0.0005160349252892625,
+      "median_m": 0.00039319775424653824,
+      "p90_m": 0.000921188305674163,
+      "mean_px": 0.5831102937318117,
+      "median_px": 0.4443095137262554,
+      "p90_px": 1.0409362877701112,
+      "visible_surface_samples": 1789,
+      "outside_mask_fraction": 0.03465623253214086,
+      "surface_to_mask_mean_px": 0.039527542889118195,
+      "surface_to_mask_p90_px": 0.0
+    }
+  ],
+  "mean_of_view_means_m": 0.00059961655100758
+}
\ No newline at end of file
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/reprojection_residuals.npz b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/reprojection_residuals.npz
new file mode 100644
index 0000000000000000000000000000000000000000..a12810b7e0c1ddc33b0aa10cbcdd5621fb905839
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/reprojection_residuals.npz
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6072f02f25a27a5f8f5a6958385ac1eb54cf979809355a03f1a7c106cd575e25
+size 1841208
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/residuals.npz b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/residuals.npz
new file mode 100644
index 0000000000000000000000000000000000000000..becea1561ad3df95e61121c3ce4cf22bf8abf978
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/residuals.npz
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d559753ccddd835a0f240373df0b5afc5091da496eaf1685d89b7cd74e6a42de
+size 2369974
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/rounds.jsonl b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/rounds.jsonl
new file mode 100644
index 0000000000000000000000000000000000000000..f21f2c152c9de7a144bf17c510c6302aef89f10a
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/rounds.jsonl
@@ -0,0 +1 @@
+{"loss": 5.64063957426697e-05, "components": {"distance": 6.267603566811886e-06, "curvature": 2.9662308165256945e-08, "arclength": 0.0, "mask_reprojection_2d": 5.0109130825148895e-05}, "grad_norm": 0.00020523875718936324, "arclength_m": 0.6656367182731628, "arclength_bound_active_within_1mm": true, "max_curvature_per_m": 13.758085250854492, "curvature_p50_p90_per_m": [9.229823112487793, 12.103294563293456], "curvature_above_max_fraction": 0.436, "mean_distance_m": 0.0029467170108525634, "max_distance_m": 0.012048400938510895, "beyond_2delta_fraction": 0.002813039264354774, "at_cap_fraction": 0.0, "per_view": [{"view": 0, "count": 9620, "median_m": 0.002988048829138279, "p90_m": 0.00560659090988338, "max_m": 0.011225677095353603, "beyond_2delta_fraction": 0.0007276507276507277, "at_cap_fraction": 0.0}, {"view": 1, "count": 13090, "median_m": 0.001513904018793255, "p90_m": 0.004024862358346582, "max_m": 0.009322958998382092, "beyond_2delta_fraction": 0.0, "at_cap_fraction": 0.0}, {"view": 2, "count": 10056, "median_m": 0.0024846148444339633, "p90_m": 0.005472885211929679, "max_m": 0.012048400938510895, "beyond_2delta_fraction": 0.004077167859984089, "at_cap_fraction": 0.0}, {"view": 3, "count": 9537, "median_m": 0.004310430493205786, "p90_m": 0.008035261370241641, "max_m": 0.011003976687788963, "beyond_2delta_fraction": 0.00744468910558876, "at_cap_fraction": 0.0}], "ribbon": {"width_m": 0.02500000037252903, "twist_rate_p90_max_per_m": [0.00018442391738062724, 0.00019782820891123265], "theta_at_knots_rad": [-7.558267043350497e-06, -5.4865431593498215e-06, -3.0992846404842567e-06, 8.272872946690768e-06, 1.7767291865311563e-05, 1.7871505406219512e-05, 1.688728661974892e-05, 1.0882817150559276e-05, -3.7029883515060646e-06], "theta_min_max_rad": [-7.652295607840642e-06, 1.8543687474448234e-05], "width_direction_abs_z_mean": 0.9968580948098288, "closest_u_abs_mean": 0.5230010878438688, "closest_u_at_width_edge_fraction": 0.09663617237548164}, "round": 1, "relative_loss_change": 0.9868065337776762}
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/spline_fit.json b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/spline_fit.json
new file mode 100644
index 0000000000000000000000000000000000000000..37d3b0547ea45769e4b8c179ef2a96de1f7d6c1d
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/spline_fit.json
@@ -0,0 +1,64 @@
+{
+  "version": 1,
+  "M": 9,
+  "basis_function": "JaxB3",
+  "closed": true,
+  "control_points": [
+    [
+      0.13086803257465363,
+      -0.1925857961177826,
+      0.008953714743256569,
+      -0.05080026388168335
+    ],
+    [
+      0.057639043778181076,
+      -0.21970690786838531,
+      0.010876326821744442,
+      0.024028226733207703
+    ],
+    [
+      -0.01527949795126915,
+      -0.2138758897781372,
+      0.009993758983910084,
+      -0.008487867191433907
+    ],
+    [
+      -0.07480787485837936,
+      -0.1709834486246109,
+      0.009499894455075264,
+      0.10044636577367783
+    ],
+    [
+      -0.09183216094970703,
+      -0.09774758666753769,
+      0.00939277932047844,
+      0.026275012642145157
+    ],
+    [
+      -0.050450488924980164,
+      -0.0352436862885952,
+      0.0099642314016819,
+      0.005133716855198145
+    ],
+    [
+      0.027868017554283142,
+      -0.014735067263245583,
+      0.01013087946921587,
+      -0.14083553850650787
+    ],
+    [
+      0.10960061848163605,
+      -0.04135877639055252,
+      0.011008692905306816,
+      0.1638694852590561
+    ],
+    [
+      0.15523746609687805,
+      -0.11753161996603012,
+      0.012831398285925388,
+      -0.12632189691066742
+    ]
+  ],
+  "is_ribbon": true,
+  "ribbon_width": 0.02500000037252903
+}
\ No newline at end of file
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/spline_init.json b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/spline_init.json
new file mode 100644
index 0000000000000000000000000000000000000000..85f3f6396ec15b2c441f94ad0661681d4ff67b60
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/spline_init.json
@@ -0,0 +1,64 @@
+{
+  "version": 1,
+  "M": 9,
+  "basis_function": "JaxB3",
+  "closed": true,
+  "control_points": [
+    [
+      0.0940241813659668,
+      -0.17649279534816742,
+      0.012891304679214954,
+      0.0
+    ],
+    [
+      0.050835881382226944,
+      -0.20529159903526306,
+      0.012914471328258514,
+      0.0
+    ],
+    [
+      -0.006271190941333771,
+      -0.1985681802034378,
+      0.013098761439323425,
+      0.0
+    ],
+    [
+      -0.04996344819664955,
+      -0.15885689854621887,
+      0.013358278200030327,
+      0.0
+    ],
+    [
+      -0.060067787766456604,
+      -0.10515146702528,
+      0.013570954091846943,
+      0.0
+    ],
+    [
+      -0.031658392399549484,
+      -0.06238085404038429,
+      0.013637418858706951,
+      0.0
+    ],
+    [
+      0.021801644936203957,
+      -0.05081376060843468,
+      0.013526156544685364,
+      0.0
+    ],
+    [
+      0.07540806382894516,
+      -0.07559914141893387,
+      0.013289835304021835,
+      0.0
+    ],
+    [
+      0.10379724949598312,
+      -0.12555773556232452,
+      0.013038373552262783,
+      0.0
+    ]
+  ],
+  "is_ribbon": true,
+  "ribbon_width": 0.02500000037252903
+}
\ No newline at end of file
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/spline_stage1.json b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/spline_stage1.json
new file mode 100644
index 0000000000000000000000000000000000000000..d5a142462e83e9edab28e16e595d8989bccf2a38
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/spline_stage1.json
@@ -0,0 +1,64 @@
+{
+  "version": 1,
+  "M": 9,
+  "basis_function": "JaxB3",
+  "closed": true,
+  "control_points": [
+    [
+      0.13086803257465363,
+      -0.1925857961177826,
+      0.008953714743256569,
+      -8.44940404931549e-06
+    ],
+    [
+      0.057639043778181076,
+      -0.21970690786838531,
+      0.010876326821744442,
+      -4.6987688619992696e-06
+    ],
+    [
+      -0.01527949795126915,
+      -0.2138758897781372,
+      0.009993758983910084,
+      -5.674777639796957e-06
+    ],
+    [
+      -0.07480787485837936,
+      -0.1709834486246109,
+      0.009499894455075264,
+      8.802170668786857e-06
+    ],
+    [
+      -0.09183216094970703,
+      -0.09774758666753769,
+      0.00939277932047844,
+      2.0103338101762347e-05
+    ],
+    [
+      -0.050450488924980164,
+      -0.0352436862885952,
+      0.0099642314016819,
+      1.7388225387549028e-05
+    ],
+    [
+      0.027868017554283142,
+      -0.014735067263245583,
+      0.01013087946921587,
+      1.7572789147379808e-05
+    ],
+    [
+      0.10960061848163605,
+      -0.04135877639055252,
+      0.011008692905306816,
+      1.3644331374962348e-05
+    ],
+    [
+      0.15523746609687805,
+      -0.11753161996603012,
+      0.012831398285925388,
+      -6.8532140176102985e-06
+    ]
+  ],
+  "is_ribbon": true,
+  "ribbon_width": 0.02500000037252903
+}
\ No newline at end of file
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/twist_trajectory.jsonl b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/twist_trajectory.jsonl
new file mode 100644
index 0000000000000000000000000000000000000000..ff26406152315cd0001cc24ddfdc07f323a9565c
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/spline/twist_trajectory.jsonl
@@ -0,0 +1,10 @@
+{"iteration": 1, "loss": 1.1255653589614667e-05, "raw_theta": [-0.044190967846327624, -0.004139215805364407, 0.02409101787567587, 0.048098866763300885, 0.043200324047324185, -0.019163093005979043, -0.05935296014924138, 0.013529163864313838, -0.028456468472185432]}
+{"iteration": 2, "loss": 1.12353045551572e-05, "raw_theta": [-0.0658215703257961, -0.00026699346825502176, 0.02659543826685728, 0.071071330748131, 0.05419805385535094, -0.02709556794717127, -0.07820689610118589, 0.06236301401666611, -0.04181309983956813]}
+{"iteration": 3, "loss": 1.1151996659464203e-05, "raw_theta": [-0.07157492188140491, 0.01656339578122569, 0.00787490512207536, 0.08372392946561626, 0.047543859032200535, -0.030881803700271573, -0.1145443874102055, 0.11858647759501596, -0.07762014649272461]}
+{"iteration": 4, "loss": 1.1150783393532038e-05, "raw_theta": [-0.07043535869352463, 0.018274353707782843, 0.006252707615767506, 0.08534603634945043, 0.047640794102021565, -0.027757553776435438, -0.1162300857474213, 0.1229656279067878, -0.08176630429890398]}
+{"iteration": 5, "loss": 1.1150501450174488e-05, "raw_theta": [-0.07005031588697477, 0.01853530047882523, 0.005766239597032808, 0.08559276073233839, 0.04731213288813716, -0.027053350588370453, -0.11673665618108678, 0.12373822491776354, -0.0827804239721178]}
+{"iteration": 6, "loss": 1.1128517144243233e-05, "raw_theta": [-0.06434444342559204, 0.023176276773345366, 0.0003151557078213277, 0.08915014147215625, 0.04144574115254843, -0.018752106913751305, -0.12368057282441358, 0.1364836000051629, -0.09559356698898591]}
+{"iteration": 7, "loss": 1.1127141988254152e-05, "raw_theta": [-0.057746495118850105, 0.02316275813585537, -0.006985242965980267, 0.09595221190092222, 0.03194913946945277, -0.003648263648661748, -0.13347363384622413, 0.155747994321613, -0.11619220323557433]}
+{"iteration": 8, "loss": 1.1126179742859676e-05, "raw_theta": [-0.051459195617866826, 0.024260092864011235, -0.008200406318147741, 0.10005209190967745, 0.026954836432600222, 0.004068463110331766, -0.1400206541955055, 0.1630153095790791, -0.12528433533181904]}
+{"iteration": 9, "loss": 1.1125985110993497e-05, "raw_theta": [-0.050800264601232235, 0.02402822694050748, -0.008487866880063534, 0.10044636319912532, 0.026275012432767423, 0.00513371669542567, -0.14083554530570488, 0.1638694816644466, -0.12632189421212558]}
+{"iteration": 10, "loss": 1.1125985110993497e-05, "raw_theta": [-0.050800264598333755, 0.024028226939905944, -0.008487866880423573, 0.10044636320053478, 0.02627501243083818, 0.00513371669847655, -0.14083554530808823, 0.16386948166639043, -0.12632189421484072]}
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/steps/colors.json b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/steps/colors.json
new file mode 100644
index 0000000000000000000000000000000000000000..c784965c8bec2454015acdb5b9d32f3241968843
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/steps/colors.json
@@ -0,0 +1,67 @@
+{
+  "status": "ok",
+  "settings": {
+    "depth_tolerance_m": 0.025
+  },
+  "outputs": {
+    "rule": "native sRGB/255, cosine weighted over mask/depth/first-hit visible views",
+    "two_sided": true,
+    "depth_tolerance_m": 0.025,
+    "first_hit_tolerance_m": 0.0002,
+    "per_view": [
+      {
+        "view": 0,
+        "serial": "12540311",
+        "observed_vertices": 326,
+        "projected_inside": 450,
+        "first_hit": 373
+      },
+      {
+        "view": 1,
+        "serial": "12933256",
+        "observed_vertices": 282,
+        "projected_inside": 450,
+        "first_hit": 364
+      },
+      {
+        "view": 2,
+        "serial": "17736741",
+        "observed_vertices": 356,
+        "projected_inside": 450,
+        "first_hit": 378
+      },
+      {
+        "view": 3,
+        "serial": "23007103",
+        "observed_vertices": 326,
+        "projected_inside": 450,
+        "first_hit": 359
+      }
+    ],
+    "observed_vertices": 429,
+    "filled_vertices": 21,
+    "fill_color_rgb": [
+      0.39903542870848213,
+      0.34509803921568627,
+      0.30103847127459266
+    ],
+    "glb_roundtrip": {
+      "float32_positions_exact": true,
+      "vertex_colors_exact": true,
+      "uv_count": 0,
+      "vertex_reordered_on_open3d_load": true
+    },
+    "files": {
+      "colors/vertex_colors.npz": "17ce02d91ae5881b0bdad15c0a05a7b989ee109e6e0997f50df50dbcfb900394",
+      "colors/color_summary.json": "fed1171e29c916eda9b57ea27365aae9ab1637a1f031adb876295b774125211a",
+      "ribbon/shape_prior.glb": "0b2c30e43fe3c27022b0737fc9553f38481d0f46e79a59e33b5b604e160b54a9",
+      "ribbon/ribbon.ply": "0e7fa61e37913d5c88e5d4104c1887e3804bbefb31739f954d6a92562954b9e6",
+      "gaussian_data/session_20260921_232822_920324/shape_prior.glb": "0b2c30e43fe3c27022b0737fc9553f38481d0f46e79a59e33b5b604e160b54a9"
+    }
+  },
+  "code": {
+    "commit": "d1d2f1381470138dfbb3c58d448e53bfed1e0d7e",
+    "u_pin": "81c718790a37e5e0102eb77af2c6edd34a9db25f"
+  },
+  "wall_time_s": 1.1682415008544922
+}
\ No newline at end of file
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/steps/diagnose-depth.json b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/steps/diagnose-depth.json
new file mode 100644
index 0000000000000000000000000000000000000000..545f96e85253c4c88d860159230807d749f18d79
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/steps/diagnose-depth.json
@@ -0,0 +1,110 @@
+{
+  "status": "ok",
+  "settings": {
+    "correction": "none",
+    "annulus_px": [
+      20,
+      80
+    ]
+  },
+  "outputs": {
+    "report": {
+      "annulus_px": [
+        20,
+        80
+      ],
+      "interior_erosion_px": 2,
+      "correction_applied": false,
+      "views": [
+        {
+          "view": 0,
+          "serial": "12540311",
+          "annulus_count": 92945,
+          "belt_interior_count": 9854,
+          "belt_edge_count": 3737,
+          "table_median_z_m": -0.00012401869970213308,
+          "belt_interior_median_z_m": 0.01609010255783655,
+          "belt_edge_median_z_m": 0.003271125842275402,
+          "belt_minus_table_m": 0.016214121257538683,
+          "edge_minus_table_m": 0.003395144541977535,
+          "table_p10_p90_z_m": [
+            -0.0014471232353370444,
+            0.0012156596444444334
+          ],
+          "belt_interior_p10_p90_z_m": [
+            0.0027749029582622158,
+            0.024782165044356055
+          ]
+        },
+        {
+          "view": 1,
+          "serial": "12933256",
+          "annulus_count": 68085,
+          "belt_interior_count": 13360,
+          "belt_edge_count": 2890,
+          "table_median_z_m": -0.0005058559128141571,
+          "belt_interior_median_z_m": 0.010782964501522052,
+          "belt_edge_median_z_m": 0.0018792346830429074,
+          "belt_minus_table_m": 0.01128882041433621,
+          "edge_minus_table_m": 0.0023850905958570645,
+          "table_p10_p90_z_m": [
+            -0.0015711710766116438,
+            0.00013449394315021566
+          ],
+          "belt_interior_p10_p90_z_m": [
+            0.0011192199028891795,
+            0.02001653895829152
+          ]
+        },
+        {
+          "view": 2,
+          "serial": "17736741",
+          "annulus_count": 94359,
+          "belt_interior_count": 10651,
+          "belt_edge_count": 4224,
+          "table_median_z_m": 0.0020539015180771614,
+          "belt_interior_median_z_m": 0.015270963048751196,
+          "belt_edge_median_z_m": 0.004238497013420661,
+          "belt_minus_table_m": 0.013217061530674035,
+          "edge_minus_table_m": 0.0021845954953435,
+          "table_p10_p90_z_m": [
+            0.0002601132932266604,
+            0.0038094762192912857
+          ],
+          "belt_interior_p10_p90_z_m": [
+            0.003211016521765697,
+            0.023222516826146622
+          ]
+        },
+        {
+          "view": 3,
+          "serial": "23007103",
+          "annulus_count": 61323,
+          "belt_interior_count": 9886,
+          "belt_edge_count": 2904,
+          "table_median_z_m": -0.00023979439225108035,
+          "belt_interior_median_z_m": 0.013846420800038783,
+          "belt_edge_median_z_m": 0.0024474589598028618,
+          "belt_minus_table_m": 0.014086215192289864,
+          "edge_minus_table_m": 0.002687253352053942,
+          "table_p10_p90_z_m": [
+            -0.0017447719571583864,
+            0.00024240730059925665
+          ],
+          "belt_interior_p10_p90_z_m": [
+            0.0043789848153975575,
+            0.022200709962195142
+          ]
+        }
+      ]
+    },
+    "files": {
+      "inputs/depth_offset_diagnostic.json": "d9cdc492ac7eb84213e65463c1f446b92f5a596d453dcf9d8ca50228740e375c"
+    }
+  },
+  "code": {
+    "commit": "d1d2f1381470138dfbb3c58d448e53bfed1e0d7e",
+    "u_pin": "81c718790a37e5e0102eb77af2c6edd34a9db25f"
+  },
+  "wall_time_s": 0.3071320056915283
+}
\ No newline at end of file
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/steps/fit.json b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/steps/fit.json
new file mode 100644
index 0000000000000000000000000000000000000000..4940273987d6f2eb381fc787372f4726b1b68a98
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/steps/fit.json
@@ -0,0 +1,372 @@
+{
+  "status": "ok",
+  "settings": {
+    "object": {
+      "name": "grey_timing_belt",
+      "representation": "ribbon",
+      "fitter_source": "spline_estimation.timing_belt_fitting (scratch/test_timing_belt_perception.py)",
+      "dimension_source": "demonstrated 25 mm width; surface only, no interior (corpus Q1, 2026-10-25)",
+      "radius_m": null,
+      "ribbon_width_m": 0.025,
+      "step_t": 0.1,
+      "step_angle_deg": null,
+      "u_resolution": 5,
+      "overlap_rule": null,
+      "twist_penalty": {
+        "samples": 250,
+        "threshold_per_m": 10.0,
+        "huber_per_m": 30.0,
+        "cap_per_m": 80.0,
+        "weight": 5e-08
+      }
+    },
+    "max_rounds": 400,
+    "control_count": 9,
+    "relative_loss_tolerance": 1e-07,
+    "reprojection": {
+      "weight": 4.0,
+      "direction": "visible mask pixels to projected centerline",
+      "ribbon_twist_stage": "two-sided (owner Q11): visible mask pixels to projected width segments plus visible projected surface samples (off the occlusion union) to the nearest mask pixel",
+      "mask": "accepted object outside hand/occluder union",
+      "view_aggregation": "equal view means",
+      "distance": "metric image plane using per-view median visible belt depth and fx/fy",
+      "samples": 360,
+      "huber_delta_m": 0.005,
+      "smooth_cap_m": 0.035,
+      "baseline_run": null
+    },
+    "loss_config": {
+      "eval_distances": true,
+      "max_saturation_distance": 0.035,
+      "distance_huber_delta": 0.005,
+      "eval_curvature_cost": true,
+      "num_eval_reg_points": 250,
+      "lambda_curvature_cost": 5e-08,
+      "max_curvature": 10.0,
+      "curvature_huber_delta": 30.0,
+      "max_saturation_curvature": 80.0,
+      "eval_curvilinear_energy": false,
+      "lambda_curvilinear_energy": 0.001,
+      "eval_length_constraint": true,
+      "lambda_length_constraint": 0.1,
+      "arclength_bounds": [
+        0.6639999747276306,
+        0.6660000085830688
+      ]
+    },
+    "solver_config": {
+      "solver_type": "lbfgs",
+      "linesearch_type": "zoom",
+      "max_linesearch_steps": 10,
+      "grad_norm_tolerance": 0.0003,
+      "max_iter": 25
+    },
+    "ribbon_twist_refinement": {
+      "stage": "2 of 2; centerline control points frozen at stage 1, nine raw twist knots free",
+      "start": "stage-1 knots reduced modulo pi to bounded twist in (-pi/2, pi/2]",
+      "loss": "3D ribbon distance + weight x two-sided surface mask term + twist penalty",
+      "twist_penalty": {
+        "samples": 250,
+        "threshold_per_m": 10.0,
+        "huber_per_m": 30.0,
+        "cap_per_m": 80.0,
+        "weight": 5e-08
+      },
+      "solver": "SciPy L-BFGS-B, knots within +-pi*atanh(0.8) (twist within +-0.8 pi); objective / start value; ftol 1e-7 (the stage-1 relative rule), gtol 1e-12, maxls 20, maxiter = rounds x 25"
+    }
+  },
+  "outputs": {
+    "filter": {
+      "method": "Open3D.remove_statistical_outlier",
+      "nb_neighbors": 20,
+      "std_ratio": 2.0,
+      "input_count": 43751,
+      "kept_count": 42303,
+      "removed_count": 1448,
+      "per_view": [
+        {
+          "view": 0,
+          "input": 9854,
+          "kept": 9620,
+          "removed": 234,
+          "live_20_0.05_kept": 5139,
+          "no_filter_kept": 9854
+        },
+        {
+          "view": 1,
+          "input": 13360,
+          "kept": 13090,
+          "removed": 270,
+          "live_20_0.05_kept": 10166,
+          "no_filter_kept": 13360
+        },
+        {
+          "view": 2,
+          "input": 10651,
+          "kept": 10056,
+          "removed": 595,
+          "live_20_0.05_kept": 6501,
+          "no_filter_kept": 10651
+        },
+        {
+          "view": 3,
+          "input": 9886,
+          "kept": 9537,
+          "removed": 349,
+          "live_20_0.05_kept": 3829,
+          "no_filter_kept": 9886
+        }
+      ]
+    },
+    "rounds": 1,
+    "stop": "gradient_tolerance",
+    "final": {
+      "loss": 1.1125985110993497e-05,
+      "components": {
+        "distance": 6.239377853489714e-06,
+        "curvature": 2.9662308165256945e-08,
+        "arclength": 0.0,
+        "mask_reprojection_2d": 4.85694454255281e-06,
+        "twist": 0.0
+      },
+      "grad_norm": 1.2239328839314112e-07,
+      "arclength_m": 0.6656367182731628,
+      "arclength_bound_active_within_1mm": true,
+      "max_curvature_per_m": 13.758085250854492,
+      "curvature_p50_p90_per_m": [
+        9.229823112487793,
+        12.103294563293456
+      ],
+      "curvature_above_max_fraction": 0.436,
+      "mean_distance_m": 0.002945967965755432,
+      "max_distance_m": 0.012138253077864647,
+      "beyond_2delta_fraction": 0.002907595206013758,
+      "at_cap_fraction": 0.0,
+      "per_view": [
+        {
+          "view": 0,
+          "count": 9620,
+          "median_m": 0.002955671981908381,
+          "p90_m": 0.005897692404687405,
+          "max_m": 0.011453804560005665,
+          "beyond_2delta_fraction": 0.0008316008316008316,
+          "at_cap_fraction": 0.0
+        },
+        {
+          "view": 1,
+          "count": 13090,
+          "median_m": 0.001527400512713939,
+          "p90_m": 0.004019656637683512,
+          "max_m": 0.009406793862581253,
+          "beyond_2delta_fraction": 0.0,
+          "at_cap_fraction": 0.0
+        },
+        {
+          "view": 2,
+          "count": 10056,
+          "median_m": 0.0025791332591325045,
+          "p90_m": 0.005575997522100806,
+          "max_m": 0.012138253077864647,
+          "beyond_2delta_fraction": 0.004972155926809865,
+          "at_cap_fraction": 0.0
+        },
+        {
+          "view": 3,
+          "count": 9537,
+          "median_m": 0.004207869991660118,
+          "p90_m": 0.007775616366416216,
+          "max_m": 0.011057930067181587,
+          "beyond_2delta_fraction": 0.0068155604487784415,
+          "at_cap_fraction": 0.0
+        }
+      ],
+      "ribbon": {
+        "width_m": 0.02500000037252903,
+        "twist_rate_p90_max_per_m": [
+          1.877037727832794,
+          2.204266309738159
+        ],
+        "theta_at_knots_rad": [
+          -0.050911322236061096,
+          0.00613745441660285,
+          0.015087069943547249,
+          0.0699172168970108,
+          0.035111889243125916,
+          -0.015670809894800186,
+          -0.06571356952190399,
+          0.06471092998981476,
+          -0.06536029279232025
+        ],
+        "theta_min_max_rad": [
+          -0.08313477039337158,
+          0.07077524065971375
+        ],
+        "width_direction_abs_z_mean": 0.9957530638183941,
+        "closest_u_abs_mean": 0.5233570038025349,
+        "closest_u_at_width_edge_fraction": 0.09751081483582724
+      },
+      "raw_theta": [
+        -0.050800264598333755,
+        0.024028226939905944,
+        -0.008487866880423573,
+        0.10044636320053478,
+        0.02627501243083818,
+        0.00513371669847655,
+        -0.14083554530808823,
+        0.16386948166639043,
+        -0.12632189421484072
+      ]
+    },
+    "deterministic": true,
+    "partial_view_witness": {
+      "source": "synthetic upright elliptical band, four retained RP2 camera centres, both faces",
+      "seed": 6,
+      "noise_sigma_m": 0.0015,
+      "points": 288,
+      "ribbon_width_m": 0.025,
+      "truth_arclength_m": 0.664979607632856,
+      "fit_arclength_m": 0.6637027263641357,
+      "mean_point_to_ribbon_m": 0.0013682314893230796,
+      "mean_centerline_distance_to_truth_m": 0.0006032002581246964,
+      "max_centerline_distance_to_truth_m": 0.0015572715588724547,
+      "width_direction_abs_z_mean": 0.9987051767368632,
+      "width_direction_abs_z_min": 0.9958782713543136,
+      "theta_min_max_rad": [
+        -0.0679638460278511,
+        0.07198633253574371
+      ],
+      "rounds": 1,
+      "stop": "gradient_tolerance",
+      "twist_iterations": 12,
+      "twist_stop": "CONVERGENCE: RELATIVE REDUCTION OF F <= FACTR*EPSMCH"
+    },
+    "stage1_final": {
+      "loss": 5.64063957426697e-05,
+      "components": {
+        "distance": 6.267603566811886e-06,
+        "curvature": 2.9662308165256945e-08,
+        "arclength": 0.0,
+        "mask_reprojection_2d": 5.0109130825148895e-05
+      },
+      "grad_norm": 0.00020523875718936324,
+      "arclength_m": 0.6656367182731628,
+      "arclength_bound_active_within_1mm": true,
+      "max_curvature_per_m": 13.758085250854492,
+      "curvature_p50_p90_per_m": [
+        9.229823112487793,
+        12.103294563293456
+      ],
+      "curvature_above_max_fraction": 0.436,
+      "mean_distance_m": 0.0029467170108525634,
+      "max_distance_m": 0.012048400938510895,
+      "beyond_2delta_fraction": 0.002813039264354774,
+      "at_cap_fraction": 0.0,
+      "per_view": [
+        {
+          "view": 0,
+          "count": 9620,
+          "median_m": 0.002988048829138279,
+          "p90_m": 0.00560659090988338,
+          "max_m": 0.011225677095353603,
+          "beyond_2delta_fraction": 0.0007276507276507277,
+          "at_cap_fraction": 0.0
+        },
+        {
+          "view": 1,
+          "count": 13090,
+          "median_m": 0.001513904018793255,
+          "p90_m": 0.004024862358346582,
+          "max_m": 0.009322958998382092,
+          "beyond_2delta_fraction": 0.0,
+          "at_cap_fraction": 0.0
+        },
+        {
+          "view": 2,
+          "count": 10056,
+          "median_m": 0.0024846148444339633,
+          "p90_m": 0.005472885211929679,
+          "max_m": 0.012048400938510895,
+          "beyond_2delta_fraction": 0.004077167859984089,
+          "at_cap_fraction": 0.0
+        },
+        {
+          "view": 3,
+          "count": 9537,
+          "median_m": 0.004310430493205786,
+          "p90_m": 0.008035261370241641,
+          "max_m": 0.011003976687788963,
+          "beyond_2delta_fraction": 0.00744468910558876,
+          "at_cap_fraction": 0.0
+        }
+      ],
+      "ribbon": {
+        "width_m": 0.02500000037252903,
+        "twist_rate_p90_max_per_m": [
+          0.00018442391738062724,
+          0.00019782820891123265
+        ],
+        "theta_at_knots_rad": [
+          -7.558267043350497e-06,
+          -5.4865431593498215e-06,
+          -3.0992846404842567e-06,
+          8.272872946690768e-06,
+          1.7767291865311563e-05,
+          1.7871505406219512e-05,
+          1.688728661974892e-05,
+          1.0882817150559276e-05,
+          -3.7029883515060646e-06
+        ],
+        "theta_min_max_rad": [
+          -7.652295607840642e-06,
+          1.8543687474448234e-05
+        ],
+        "width_direction_abs_z_mean": 0.9968580948098288,
+        "closest_u_abs_mean": 0.5230010878438688,
+        "closest_u_at_width_edge_fraction": 0.09663617237548164
+      },
+      "round": 1,
+      "relative_loss_change": 0.9868065337776762
+    },
+    "twist": {
+      "start_raw_theta": [
+        -8.449404049335864e-06,
+        -4.698768862002774e-06,
+        -5.67477763980313e-06,
+        8.80217066880989e-06,
+        2.0103338101814704e-05,
+        1.738822538750454e-05,
+        1.757278914734104e-05,
+        1.3644331375048138e-05,
+        -6.8532140176211684e-06
+      ],
+      "start_loss": 1.132844317908166e-05,
+      "bound_raw": 3.451392295223203,
+      "knots_at_bound": 0,
+      "iterations": 10,
+      "evaluations": 65,
+      "stop": "CONVERGENCE: RELATIVE REDUCTION OF F <= FACTR*EPSMCH",
+      "success": true
+    },
+    "files": {
+      "spline/reprojection_residuals.npz": "6072f02f25a27a5f8f5a6958385ac1eb54cf979809355a03f1a7c106cd575e25",
+      "spline/residuals.npz": "d559753ccddd835a0f240373df0b5afc5091da496eaf1685d89b7cd74e6a42de",
+      "spline/filtered_cloud.npz": "79969ed1420c084352424b29f38c643e47f8caae3974f51f57a484323d29585c",
+      "spline/spline_init.json": "dc31754bbd876c342009fffb0eebdc9ad15b9876cd2c91c7fe1b01da16c10c09",
+      "spline/determinism.json": "e5ed40ea623c8519288ce80b1c86a50778bc2a4ba34bcb965ece98912a11c354",
+      "spline/filter.json": "0f253e135e5b5b5fb8ac4c07ab1c4134c7b36bbcd96845deb943c5c7fcefdf8c",
+      "spline/witness.json": "7b8b69d19e90d19bc910732039cb9c9bf51ad01e75ac47a45a8eda09dd361392",
+      "spline/filter_removed.npz": "a734dac86512a99159188400663e843df59fa953d397db5ce94f7ee634229676",
+      "spline/spline_stage1.json": "f5cc846bb0aab2a61a78bfd5e126554b155320c7834855c097071b887b621142",
+      "spline/twist_trajectory.jsonl": "f3f4872928559906ad045e1d400058230ebd15357a39fee755f54a4b685acfc5",
+      "spline/spline_fit.json": "ff195005d62377bdfb215a588bb3502a7d86c95f5df6fdda46bfae48f9dfad8e",
+      "spline/rounds.jsonl": "cd0991b45876158f5f1ca334fc3f94c9c0a978fbc6b9e8af25e4e0e763b65df9",
+      "spline/init_ellipse.json": "ec1efab4e2826e9a945cbcdb7525b9c42b724b08feaba31f250d4ca5afdb6a99",
+      "spline/reprojection.json": "9863c1ef13a69bb686626bd72cd426617c64be8a1433a0c680250de0c2d109c0"
+    }
+  },
+  "code": {
+    "commit": "d1d2f1381470138dfbb3c58d448e53bfed1e0d7e",
+    "u_pin": "81c718790a37e5e0102eb77af2c6edd34a9db25f"
+  },
+  "wall_time_s": 63.767921924591064
+}
\ No newline at end of file
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/steps/hybrid.json b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/steps/hybrid.json
new file mode 100644
index 0000000000000000000000000000000000000000..44ae53326d80097128070c8ffc436200e8c94eed
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/steps/hybrid.json
@@ -0,0 +1,24 @@
+{
+  "status": "ok",
+  "settings": {
+    "u_pin": "81c718790a37e5e0102eb77af2c6edd34a9db25f",
+    "numpy_seed": 0,
+    "points_per_triangle": 30
+  },
+  "outputs": {
+    "counts": {
+      "observed": 42303,
+      "mesh": 21600,
+      "total": 63903,
+      "mesh_to_observed": 0.5106020849585136
+    },
+    "files": {
+      "hybrid/populations.npz": "2c485024f39174c98aa20f6f12f319bcccc4e7c52d7df8e965c81e310fb038e1"
+    }
+  },
+  "code": {
+    "commit": "d1d2f1381470138dfbb3c58d448e53bfed1e0d7e",
+    "u_pin": "81c718790a37e5e0102eb77af2c6edd34a9db25f"
+  },
+  "wall_time_s": 0.8447673320770264
+}
\ No newline at end of file
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/steps/inputs.json b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/steps/inputs.json
new file mode 100644
index 0000000000000000000000000000000000000000..d2ed571e7cfb5cb7c808788a633c596a980e9f04
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/steps/inputs.json
@@ -0,0 +1,216 @@
+{
+  "status": "ok",
+  "settings": {
+    "object": "grey_timing_belt",
+    "depth_source": "waft_stereo_dav2l5",
+    "depth_stream_ids": [
+      "zed_12540311_depth_waft_stereo_synlarge_dav2l5_zdepth",
+      "zed_12933256_depth_waft_stereo_synlarge_dav2l5_zdepth",
+      "zed_17736741_depth_waft_stereo_synlarge_dav2l5_zdepth",
+      "zed_23007103_depth_waft_stereo_synlarge_dav2l5_zdepth"
+    ],
+    "frames": "/mnt/data2/magna/belt_perception_shared/phystwin_model_corpus_expansion/lab/session_20260921_232822_920324/window_anchor0331-0765/accepted_input_preparation_c6a_v1/frames_waft/per_camera_inputs.json",
+    "frames_sha256": "26bea474ca8e5350b648271f6119ab15a49dd2dec0deab6ee0e02b68beaaab2d",
+    "signed_native_frames_sha256": {
+      "12540311": "c8f6e415a7c80eb2337286753c3eccbac1a14a0d47ef5c60b704a6572829591d",
+      "12933256": "ca5a4cf4579162018ca1ae52ee347895e489c3d4a0ff8884c2cc19167ee61433",
+      "17736741": "4c1bd82f8c534880acb9718fe5636f1513133c6ddd785d212c6eea46a16aa2ea",
+      "23007103": "64329f6d79e5be632d63e9c344cb345363d0aaa401138fd4153d65c3be533cc6"
+    },
+    "camera_frames_sha256": {
+      "12540311": "f8d57f463997df49ef7e011a8fd946c33e18b9569eb79481baeec6a07014f8b6",
+      "12933256": "ba25acf17d91ccb96c6a756756645ba01dddfdd543f117e4baeeadbd56cfbefb",
+      "17736741": "ecaac0cf787955ca796b1975f65941b1e44456635340aed0470ad007f8bd8d7e",
+      "23007103": "7dc9ea608f94f716c08ab664b65211ea5a1f8a96b91564f246a8ee1d56aa43c5"
+    },
+    "mask_erosion_px": 2,
+    "filter": {
+      "method": "Open3D.remove_statistical_outlier",
+      "nb_neighbors": 20,
+      "std_ratio": 2.0,
+      "input_count": 43751,
+      "kept_count": 42303,
+      "removed_count": 1448,
+      "per_view": [
+        {
+          "view": 0,
+          "input": 9854,
+          "kept": 9620,
+          "removed": 234,
+          "live_20_0.05_kept": 5139,
+          "no_filter_kept": 9854
+        },
+        {
+          "view": 1,
+          "input": 13360,
+          "kept": 13090,
+          "removed": 270,
+          "live_20_0.05_kept": 10166,
+          "no_filter_kept": 13360
+        },
+        {
+          "view": 2,
+          "input": 10651,
+          "kept": 10056,
+          "removed": 595,
+          "live_20_0.05_kept": 6501,
+          "no_filter_kept": 10651
+        },
+        {
+          "view": 3,
+          "input": 9886,
+          "kept": 9537,
+          "removed": 349,
+          "live_20_0.05_kept": 3829,
+          "no_filter_kept": 9886
+        }
+      ]
+    },
+    "parent": null,
+    "unfitted_inputs": true,
+    "fitting_bundle_sha256": "9dc6b7b274ebe0c7eca27e807e4ed9b9802c3908e1f98fd4141d7d57bc1b5589",
+    "signoffs": {
+      "/mnt/data2/magna/belt_perception_shared/phystwin_model_corpus_expansion/lab/session_20260921_232822_920324/window_anchor0331-0765/native_inputs/cameras/12540311/review_signoff.json": "834f0909f06fb9ce3bbd633dd0cf58c1de1b42765adb0c8f2fe31e2aaf6c7657",
+      "/mnt/data2/magna/belt_perception_shared/phystwin_model_corpus_expansion/lab/session_20260921_232822_920324/window_anchor0331-0765/native_inputs/cameras/12540311/review_signoff_occluder.json": "d0ca49613b8a6831c7143eb668485804675c4ef5078f4ac777dd06b5a35568bf",
+      "/mnt/data2/magna/belt_perception_shared/phystwin_model_corpus_expansion/lab/session_20260921_232822_920324/window_anchor0331-0765/native_inputs/cameras/12933256/review_signoff.json": "c4c27ad9b5ea736a9b526a21b0a14fa663f365feaa61ed89d5585f7380a3b998",
+      "/mnt/data2/magna/belt_perception_shared/phystwin_model_corpus_expansion/lab/session_20260921_232822_920324/window_anchor0331-0765/native_inputs/cameras/12933256/review_signoff_occluder.json": "560dfd4076c288c592813dd16696abe557eb65e6390b1c164a1a16c94e7cb9db",
+      "/mnt/data2/magna/belt_perception_shared/phystwin_model_corpus_expansion/lab/session_20260921_232822_920324/window_anchor0331-0765/native_inputs/cameras/17736741/review_signoff.json": "cffdb40eb24e55165d81938f177f213bc81f1480f2d1a8b7a5d5378279b71bcc",
+      "/mnt/data2/magna/belt_perception_shared/phystwin_model_corpus_expansion/lab/session_20260921_232822_920324/window_anchor0331-0765/native_inputs/cameras/17736741/review_signoff_occluder.json": "fd555c92ed1c73ad00bf7673e6baca7c05333cc14be8409eae479ee3a1ead3ff",
+      "/mnt/data2/magna/belt_perception_shared/phystwin_model_corpus_expansion/lab/session_20260921_232822_920324/window_anchor0331-0765/native_inputs/cameras/23007103/review_signoff.json": "ded6d0307b35c4604ae20921df17d2e0bc49b88bf0a6094825e272a4c9cf8582",
+      "/mnt/data2/magna/belt_perception_shared/phystwin_model_corpus_expansion/lab/session_20260921_232822_920324/window_anchor0331-0765/native_inputs/cameras/23007103/review_signoff_occluder.json": "9618440a92373d6c45dbd90dee078a9191e5b1254deb2b2c4473cd995ac62a83"
+    }
+  },
+  "outputs": {
+    "reference": {
+      "case": "session_20260921_232822_920324",
+      "grid_sample": 0,
+      "views": [
+        {
+          "index": 0,
+          "serial": "12540311",
+          "native_frame": 0,
+          "offset_ms": 14.115702,
+          "object_mask_px": 13591,
+          "invalid_depth_in_mask_px": 0,
+          "occlusion_union_px": 132804,
+          "object_and_union_px": 0,
+          "lifted_points": 9620,
+          "lifted_z_min_max_m": [
+            -0.0023284568863624067,
+            0.030775777860925224
+          ],
+          "uneroded_lifted_points": 13591,
+          "uneroded_lifted_z_min_max_m": [
+            -0.0027910377797614183,
+            0.033030069574933485
+          ],
+          "eroded_lifted_points": 9854,
+          "erosion_removed_points": 3737,
+          "outlier_removed_points": 234
+        },
+        {
+          "index": 1,
+          "serial": "12933256",
+          "native_frame": 0,
+          "offset_ms": 9.747829,
+          "object_mask_px": 16250,
+          "invalid_depth_in_mask_px": 0,
+          "occlusion_union_px": 154087,
+          "object_and_union_px": 0,
+          "lifted_points": 13090,
+          "lifted_z_min_max_m": [
+            -0.002801856618944276,
+            0.026847888060681613
+          ],
+          "uneroded_lifted_points": 16250,
+          "uneroded_lifted_z_min_max_m": [
+            -0.004181857039834647,
+            0.0658507626346585
+          ],
+          "eroded_lifted_points": 13360,
+          "erosion_removed_points": 2890,
+          "outlier_removed_points": 270
+        },
+        {
+          "index": 2,
+          "serial": "17736741",
+          "native_frame": 0,
+          "offset_ms": 3.26476,
+          "object_mask_px": 14875,
+          "invalid_depth_in_mask_px": 0,
+          "occlusion_union_px": 191232,
+          "object_and_union_px": 0,
+          "lifted_points": 10056,
+          "lifted_z_min_max_m": [
+            -0.0009281391361578573,
+            0.033362889615193514
+          ],
+          "uneroded_lifted_points": 14875,
+          "uneroded_lifted_z_min_max_m": [
+            -0.003730801897673608,
+            0.03483003928452533
+          ],
+          "eroded_lifted_points": 10651,
+          "erosion_removed_points": 4224,
+          "outlier_removed_points": 595
+        },
+        {
+          "index": 3,
+          "serial": "23007103",
+          "native_frame": 0,
+          "offset_ms": 0.0,
+          "object_mask_px": 12790,
+          "invalid_depth_in_mask_px": 0,
+          "occlusion_union_px": 143608,
+          "object_and_union_px": 0,
+          "lifted_points": 9537,
+          "lifted_z_min_max_m": [
+            -0.0023284850348738173,
+            0.02761780733439978
+          ],
+          "uneroded_lifted_points": 12790,
+          "uneroded_lifted_z_min_max_m": [
+            -0.004463492111132172,
+            0.02901916985910713
+          ],
+          "eroded_lifted_points": 9886,
+          "erosion_removed_points": 2904,
+          "outlier_removed_points": 349
+        }
+      ],
+      "observed_points": 42303,
+      "mask_erosion_px": 2
+    },
+    "files": {
+      "inputs/observed_cloud.npz": "1f8d4283cb7cca51355433490faa124ae2b993d896ba744c5d38551094df395a",
+      "inputs/reference_views.json": "e9a79e571a910ac8a9d7715434dd96207b7f3c4925b7adf0935f7c0eebb3ec2c",
+      "gaussian_data/session_20260921_232822_920324/0.png": "5fefb36318cab8ef184e4da60e609a87ace523121600c79901e59790d5acc98a",
+      "gaussian_data/session_20260921_232822_920324/mask_0.png": "6bd219bf2827a0c92f14ec547ab937d348245965cfeecdc99270f9dee7e8376b",
+      "gaussian_data/session_20260921_232822_920324/mask_human_0.png": "f7ba4bb6d4946a01f42b610c450188a9b619987e2cbbf115fe40285ae6ad1458",
+      "gaussian_data/session_20260921_232822_920324/0_depth.npy": "9c85d347cb09fe3ff2ff5504244188893394a4eb5f160e67a58d0395fcf3e2a0",
+      "gaussian_data/session_20260921_232822_920324/1.png": "e18d763cc5fc528dd31e061b68ac2512645ef60fb997a35d70880ea8f5209ba6",
+      "gaussian_data/session_20260921_232822_920324/mask_1.png": "c93d3c0079fda0a84bf7a650673bea0182a00607c231c813d66414166f7eca48",
+      "gaussian_data/session_20260921_232822_920324/mask_human_1.png": "af8097e786cd1ee341b5420f30991e2f0f4570b255a9c6fbd9298bd0bf0eb7ef",
+      "gaussian_data/session_20260921_232822_920324/1_depth.npy": "db673693ca01bcd4909243de7bcae165fcf4a5578dadb3c8969492fc8f9f724b",
+      "gaussian_data/session_20260921_232822_920324/2.png": "ac26a550aced8911edc02f18300c1a5715f8886c8528081191a010da26f2664d",
+      "gaussian_data/session_20260921_232822_920324/mask_2.png": "fb98637c06a056622d0c90b1fd7d89861a832720cefedfb78af816c15756d4ec",
+      "gaussian_data/session_20260921_232822_920324/mask_human_2.png": "3d37f8d46e6be2d409133a55a54b519b500f632e6f2ccec593efc64d55257f57",
+      "gaussian_data/session_20260921_232822_920324/2_depth.npy": "9165a02dd2adbac976a53ef9f5fdb5846fde9817de58ce01efd8825447ef0487",
+      "gaussian_data/session_20260921_232822_920324/3.png": "61fbe1aa6b28b3741994a1bd38bd4233725f5b7a4643de73411a7c70ee7a93c1",
+      "gaussian_data/session_20260921_232822_920324/mask_3.png": "080b6403f066b73b03d015bc510d6e0b75625523572e4c0d30a7153c1587c3c7",
+      "gaussian_data/session_20260921_232822_920324/mask_human_3.png": "129c10fe7c602811fea7f514bf1111e51a5c0bcb5e97360accb204204b56fd53",
+      "gaussian_data/session_20260921_232822_920324/3_depth.npy": "96067a19a8e8763259dbb1ad0d3be8bac73d138c5a5c9e69028dab038a2eefff",
+      "gaussian_data/session_20260921_232822_920324/camera_meta.pkl": "3e88eba07fa7a1c6aac0e3fdcc97b3228d69ea9eca593f11b9cb927a6990d31b",
+      "gaussian_data/session_20260921_232822_920324/interp_poses.pkl": "b90cc26123c822f0d06446ac699e110db22a86e265c56751819029a46f558b6f",
+      "gaussian_data/session_20260921_232822_920324/observation.ply": "158e3efd97ba375d9d3a7f994e162f9331a7eb828de848647984bdfc59c9772f",
+      "spline/filter.json": "0f253e135e5b5b5fb8ac4c07ab1c4134c7b36bbcd96845deb943c5c7fcefdf8c",
+      "spline/filter_removed.npz": "a734dac86512a99159188400663e843df59fa953d397db5ce94f7ee634229676",
+      "spline/filtered_cloud.npz": "79969ed1420c084352424b29f38c643e47f8caae3974f51f57a484323d29585c"
+    }
+  },
+  "code": {
+    "commit": "d1d2f1381470138dfbb3c58d448e53bfed1e0d7e",
+    "u_pin": "81c718790a37e5e0102eb77af2c6edd34a9db25f"
+  },
+  "wall_time_s": 31.35102105140686
+}
\ No newline at end of file
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/steps/review.json b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/steps/review.json
new file mode 100644
index 0000000000000000000000000000000000000000..0c7e469793bb60f108f56fe815412d54cfefa6f3
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/steps/review.json
@@ -0,0 +1,66 @@
+{
+  "status": "ok",
+  "settings": {
+    "historical_prior": null,
+    "historical_sha256": null,
+    "baseline_fit": null
+  },
+  "outputs": {
+    "review_files": 53,
+    "files": {
+      "review/hybrid/combined.png": "694dd87c293b1eece55eae152a4dd5af91883b7cf46ad5cc7b4d3b1c7bda5a04",
+      "review/hybrid/mesh.png": "4a8f1a3080ef140962eac3e2faaf3fcb7c33462e830a92cb4251dfec2fd5048b",
+      "review/hybrid/observed.png": "2c646e585e86d442eef7afb40e9c28682c495f3c16a83adcced5e72b1fdaa04a",
+      "review/inputs/depth_offset_table.json": "d9cdc492ac7eb84213e65463c1f446b92f5a596d453dcf9d8ca50228740e375c",
+      "review/inputs/depth_offset.png": "68f215008bf0af7fa5bba250e2ff0895562283e80177cb3270b4ff95e5da8a4e",
+      "review/inputs/view_3_23007103.png": "d05fb51d36021bd9587a793e993bd9f5bb6e808f9f6c6c4dd231b22f4742fb58",
+      "review/inputs/view_0_12540311.png": "cf7ac45a7ee18ca34b965169ea54af3df64b3d77334d027634050417ef6944d4",
+      "review/inputs/view_1_12933256.png": "0eccd5dc91d7276d5753840a0618ad0fa5b3e0363fb6e915b6c4eb2677450623",
+      "review/inputs/cloud_rgb.png": "9c7e4d338c31293db1f5eb86febf997eeb4c0a08e5798e7fc49e5f60c07f1634",
+      "review/inputs/filter_removed.png": "e98b02f48e248cf8f51da456b05b64a62c81b832bf833dc8af1cffe7f3075f47",
+      "review/inputs/cloud_by_view.png": "f480b013633a6c85ec810176c2345140dc458f740a755f6d578f75121b9e1f51",
+      "review/inputs/view_2_17736741.png": "acefe02a87c44ec58d44095cb0c74fcc344f56bca588e2523289179f63a4b75b",
+      "review/rerun/headless_contact_sheet.png": "8895d6944b109fede39103cbbfbbcd91acf785fc2b6d3c4cc7afb60f3a1b3bcc",
+      "review/spline/centerline_0_with_masks.png": "74f48ea3b29d297ac654bae0c820cbee8edc97885918e5fcae5434b0f168c399",
+      "review/spline/centerline_3_unmasked.png": "fd69b56dacd2636bed2506aea93beea11e064957fa0cd4038e8a5066d8209850",
+      "review/spline/per_view_arc_coverage.png": "a739551062d7841caf101cc8707d28d40fbc1e7808a318acf7577ae2bc28abea",
+      "review/spline/fit_projections.png": "34d8ed157a9c5e6ab1c3ec54244f2e9efc45cd175ff0c8fddd27f39a20cc735c",
+      "review/spline/centerline_1_unmasked.png": "1935ca6bd54172661246a7e685ea5a21ab76a97e2ab3723ac79ebc841ca6f412",
+      "review/spline/centerline_2_with_masks.png": "30ff90fb7dbc88b8c8f36c085c6da30069b39785531444b8c18a4c88b588c0ab",
+      "review/spline/centerline_1_with_masks.png": "95c77b22a1064bf5d7bc3f09615f930f50913d75f8dba56e24cd0b458338586d",
+      "review/spline/centerline_2_unmasked.png": "01fc324015ee92131d822d4c1102c759f41cb129c7f631ad4f34aed585271738",
+      "review/spline/round_curves.png": "feb7b67b19e86c8e48854ef9210043a5dc0e9fd4da70641db0dbc7a4a73fa5df",
+      "review/spline/curvature_profile.png": "0b42af8808b8a22ec2fca3d3f3508908aee61ab916595e097b674abb0d421f33",
+      "review/spline/residual_histograms.png": "6ce027c709d83858e2c6b6433ed15fb14d88ba0552115898a51b9edb0ff23c4a",
+      "review/spline/centerline_3_with_masks.png": "818d84a4655b66553b2cbcc5d7b1613d4bdb461486539912c0341be99e63441e",
+      "review/spline/fit_3d.png": "72e73b50e17cb72884d51f564e50f2bf3a31077dbf1c032cc696333925c4d513",
+      "review/spline/centerline_0_unmasked.png": "02faa6d839c10bfdfc784f6cc64a5a79471e5857295d5d396e1361951a8ff6d3",
+      "review/colors/fill_swatch.txt": "c3f8572cab9e2be4741966f9fbc6405ec5045095a90be396ef396c4e2f6b71f9",
+      "review/colors/view_2_visibility.png": "42c8407563d01818bdffaf601da408c68d232c37f98733d37d12738c0ddbaf64",
+      "review/colors/view_1_visibility.png": "5e48ad333c23cf2e0d00f3ed742c4597b40d33e89377c63d97bdf21cdef60dae",
+      "review/colors/visibility_and_fill.png": "814800221c88bcf2b41e4203dad0ff880742830fcd917eb746919d201a7a391f",
+      "review/colors/view_0_visibility.png": "f10e741dd79cb7d45734fb5bde5633cae75172030a913b76a2a47f5edada4f6f",
+      "review/colors/fill_swatch.png": "58164a5af51062d045d76400e85ad4e87cfa840c1aebcf563967be27fcac72ae",
+      "review/colors/view_3_visibility.png": "fa43aa594020af40c31d8f070e532e4808392ee672d26f25f8687389b39466d2",
+      "review/ribbon/silhouette_1_unmasked.png": "6ab8ec8a4464638e0e9d4fafa21dd2075cf89a4912f811d29a908be4921266e7",
+      "review/ribbon/silhouette_0_unmasked.png": "a7aa7d87d76ea030ca47b743e59c96f027748ec6cb2bc1566b6965f33565e408",
+      "review/ribbon/twist_and_width_direction.png": "70e388290a78b24dcfd749a402203de0b2451599517c42cbac1ad198b241d12b",
+      "review/ribbon/ribbon_profiles.png": "47f96f7475e7b7b831219417cea0f34570416d2bb42c50f6d0aa11e0bcfbd466",
+      "review/ribbon/ribbon_scale_views.png": "b768d9cdbb6ad4b142885ea7cb2fd73179d147591a150ea1958945cd143791c0",
+      "review/ribbon/silhouette_0_with_masks.png": "2107f3e3b3ef51c7af6fd075dfeb798e643826c24c6634cc05c651ef518a3f82",
+      "review/ribbon/silhouette_1_with_masks.png": "ff74f30b793bfa1ca13ede0f58d44a8e9e3531ba343b67e978791bc4ff5a2843",
+      "review/ribbon/silhouette_2_unmasked.png": "1e35410572d9763ae5f42f6ad1c94da0e8aa4e4c3c049a437f44d9867c104756",
+      "review/ribbon/silhouette_3_with_masks.png": "3e4afd357e896ce907fd9a6742b2b3784be43edcf0584f95c91e925f05a398b6",
+      "review/ribbon/silhouette_2_with_masks.png": "154f6c569edaa9992732c59334277e20940749622f28cf80beecb471762b9432",
+      "review/ribbon/check_table.json": "acb80125f8e0140f7a9d28f2f6b2907cc366e33c3b848ea3981888a3ec4df6f9",
+      "review/ribbon/orbit.mp4": "ebb641bfb0efa7c6199547886308ab819b28a4f39493254333c5a2647714f2e7",
+      "review/ribbon/silhouette_3_unmasked.png": "a537e926692e297ae162f4abb7bc7e2a87622abc298b875c2d6171b5b2505de4",
+      "rerun/appearance_spline_prior.rrd": "6f8ce5984afa19ce00d325c31ec6338353ea5d6cbc7ec8c609c5cf4efd4216a0"
+    }
+  },
+  "code": {
+    "commit": "d1d2f1381470138dfbb3c58d448e53bfed1e0d7e",
+    "u_pin": "81c718790a37e5e0102eb77af2c6edd34a9db25f"
+  },
+  "wall_time_s": 15.316488265991211
+}
\ No newline at end of file
diff --git a/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/steps/ribbon.json b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/steps/ribbon.json
new file mode 100644
index 0000000000000000000000000000000000000000..aebeee1cfb8f54f424439dcd8aefac693121bd3a
--- /dev/null
+++ b/sessions/session_20260921_232822_920324/preprocessing/timing-belt-ribbon-prior-v1/native/steps/ribbon.json
@@ -0,0 +1,71 @@
+{
+  "status": "ok",
+  "settings": {
+    "width_m": 0.02500000037252903,
+    "step_t": 0.1,
+    "u_resolution": 5,
+    "interior": "none (owner surface-only route)"
+  },
+  "outputs": {
+    "checks": {
+      "representation": "zero-thickness intrinsic ribbon surface (open width edges)",
+      "euler_characteristic": 0,
+      "watertight": false,
+      "components": 1,
+      "winding_consistent": true,
+      "boundary_loop_edges": [
+        90,
+        90
+      ],
+      "degenerate_triangles": 0,
+      "open3d_reported_intersecting_pairs": 0,
+      "confirmed_intersecting_pairs": [],
+      "self_intersecting": false,
+      "maximum_width_error_m": 3.467930685674414e-09,
+      "maximum_midline_error_m": 3.736641687737786e-09,
+      "maximum_tangent_width_dot": 5.966961243546176e-07,
+      "seam_surface_error_m": 0.0,
+      "minimum_nonadjacent_centerline_distance_m": 0.013778813717554317,
+      "theta_min_max_rad": [
+        -0.08293568342924118,
+        0.0707787498831749
+      ],
+      "width_direction_abs_z_mean": 0.9957387096676589,
+      "triangle_area_m2": {
+        "min": 2.1185713303117386e-05,
+        "median": 2.260841702941023e-05,
+        "mean": 2.3108186075747983e-05,
+        "max": 2.601480649752073e-05,
+        "density_max_over_min": 1.2279410244682563
+      },
+      "bounds_m": [
+        [
+          -0.08502081036567688,
+          -0.2170107066631317,
+          -0.0029200988356024027
+        ],
+        [
+          0.14453162252902985,
+          -0.022457193583250046,
+          0.0244786124676466
+        ]
+      ],
+      "width_m": 0.02500000037252903,
+      "step_t": 0.1,
+      "u_resolution": 5,
+      "passed": true
+    },
+    "vertex_count": 450,
+    "triangle_count": 720,
+    "files": {
+      "ribbon/triangle_areas.npz": "1e597ea2c4995a567ec5e98acab6acf4775acf80c1f7bd6cb32e393333c0d4aa",
+      "ribbon/geometry.npz": "0e6d9e6c856a74a3b14a0748305b897b33315226c841951c8bb2e65b52af7fed",
+      "ribbon/ribbon_checks.json": "acb80125f8e0140f7a9d28f2f6b2907cc366e33c3b848ea3981888a3ec4df6f9"
+    }
+  },
+  "code": {
+    "commit": "d1d2f1381470138dfbb3c58d448e53bfed1e0d7e",
+    "u_pin": "81c718790a37e5e0102eb77af2c6edd34a9db25f"
+  },
+  "wall_time_s": 3.410750389099121
+}
\ No newline at end of file