gnn_data/README.md

---
license: cc-by-4.0
task_categories: [robotics, image-segmentation, graph-ml]
language: [en]
tags: [robotics, manipulation, disassembly, tower-of-hanoi, constraint-graph, gnn, world-model, sam2, segmentation, ur5e]
size_categories: [1K<n<10K]
pretty_name: GNN Constraint-Aware World Model Dataset (v3)
---

# GNN Constraint-Aware World Model Dataset (v3)

Real robot episodes with per-frame constraint graphs, SAM2 segmentation masks + 256-D feature embeddings, full 3D depth bundles, and synchronized robot states across two manipulation domains. Both domains share the v3 on-disk layout (same JSON/NPZ schemas, same delta-encoded `frame_states`, same fully-connected PyG expansion at load time) and now share a unified **270-D node feature format** — the PyG loader reads a fixed 10-D type encoding from a YAML config so both domains produce identical node dimensionality.

- **Project:** CoRL 2026 — GNN world model for constraint-aware video generation
- **Author:** Chang Liu (Texas A&M University)
- **Hardware:** UR5e + Robotiq 2F-85 gripper, OAK-D Pro (static side view)
- **Format version:** v3.0 (updated 2026-04-16)

### What's in this repo — at a glance

| Where | Contains | Use for |
|---|---|---|
| `session_*` (Desktop) and `hanoi/session_hanoi_*` | Raw episodes + per-frame `annotations/` (masks, embeddings, depth bundles, `side_graph.json`) | **Training data for the world model** |
| `config/type_encoding_*.yaml` | Fixed 10-D per-type encoding YAMLs | Loader inputs (pick one per run) |
| `tools/hanoi_pipeline/` | SAM2 FT checkpoint + all Python code to regenerate / extend / run the Hanoi pipeline end-to-end (auto-labeler, single-frame inferer, per-frame materializer) | **Reproducing or re-running the pipeline** on new Hanoi sessions; inference-time RGB→graph |
| **Not in this repo** (source repo only): `scripts/hanoi/orchestrator.py` (robot data collection), `scripts/run_annotator.sh` (browser verification UI), `scripts/sam2_finetune/` (FT training harness) | Hardware-facing and web-UI code | Clone [the source repo](https://github.com/ChangChrisLiu/gnn-world-model) if you want to collect new data, verify labels in a browser, or retrain the SAM2 FT checkpoint |

## Domains at a glance

| Domain | Graph variants offered | Node vocab size | Node feature dim | Edge feature dim | Data root |
|---|---|---|---|---|---|
| Desktop disassembly | products-only, with-robot-node, with-robot-state, with-robot-action | 9 (8 products + `robot`) | **270** | 3 | `session_<date>_<time>/episode_XX/` |
| Tower of Hanoi | products-only, with-robot-state, with-robot-action | 4 (`ring_1..ring_4`) | **270** | 3 | `hanoi/session_hanoi_<date>_<time>/episode_XX/` |

Node feature dim = `256 (SAM2 emb) + 3 (3D pos) + 10 (fixed type encoding) + 1 (visibility) = 270`. The 10-D type encoding is a **fixed, deterministic** per-type vector (NOT trained) read from `config/type_encoding_random.yaml` or `config/type_encoding_clip.yaml` at load time — so both domains, and any future component vocabulary up to 13 types, share the same node dimension.

**Four loader variants** (all return `torch_geometric.data.Data`):

- `load_pyg_frame_products_only` — V1 bare graph: products/rings only, no robot info.
- `load_pyg_frame_with_robot` — V2 ablation: robot attached as a graph NODE (Desktop only; Hanoi has no robot mask in v1, so this falls back to products-only).
- `load_pyg_frame_with_robot_state` — **V3 recommended**: products-only graph + `robot_state=[13]` side-tensor. Works for both domains because `robot_states.npy` is present everywhere.
- `load_pyg_frame_with_robot_action` — V3 action-conditioned: same as above + `robot_action=[13]` delta for the next frame.

The three paper options map cleanly: Option 1 (direct graph encoding) → `products_only`; Option 2 (encoder → latent → world model with robot context) → `with_robot_state`; Option 3 (action-conditioned GNN) → `with_robot_action`.

## File layout (same for both domains)

```
episode_XX/
├── metadata.json            # episode metadata (domain-specific extras)
├── robot_states.npy         # (T, 13) float32 — joints + TCP + gripper
├── robot_actions.npy        # (T-1, 13) float32 — frame deltas
├── timestamps.npy           # (T, 3) float64
├── side/
│   ├── rgb/frame_XXXXXX.png     # 1280×720 RGB
│   └── depth/frame_XXXXXX.npy   # 1280×720 uint16 (mm)
├── wrist/                   # raw wrist camera (not used in v3)
└── annotations/
    ├── side_graph.json          # components, static edges, frame_states
    ├── side_masks/              # {component_id: (H,W) uint8} per frame
    ├── side_embeddings/         # {component_id: (256,) float32} per frame
    ├── side_depth_info/         # flat-keyed depth bundle per frame
    ├── side_robot/              # robot bundle per frame (visible flag)
    └── dataset_card.json        # format description
```

**Alignment guarantee:** every labeled frame index has files in all four of `side_masks/`, `side_embeddings/`, `side_depth_info/`, `side_robot/`. Files are keyed by the same integer frame index, so a loader can key off the mask directory and trust the rest to be present.

## Pipeline — four stages from raw video to training-ready graphs

```
┌─────────────┐     ┌───────────────┐     ┌───────────────────┐     ┌──────────────────┐
│ Collection  │ →   │ Auto-labeling │ →   │ Verification / UI │ →   │  PyG loader @    │
│ (30 Hz RGBD │     │ (SAM2-FT)     │     │ (optional edit)   │     │  training time   │
│  + robot)   │     │               │     │                   │     │                  │
└─────────────┘     └───────────────┘     └───────────────────┘     └──────────────────┘
   episode_XX/         annotations/           annotations/             torch_geometric
                        masks, emb,            (corrected)              .data.Data
                        depth, robot,                                  x=[N,270], edge=[E,3]
                        side_graph.json
```

### Stage 1 — Collection
30 Hz synchronous capture of side RGB + depth + robot state into `episode_XX/`. No image processing or graph work happens here.
- **Desktop:** human teleop via a game controller; the operator decides what to disassemble in what order.
- **Hanoi:** autonomous — `scripts/hanoi/orchestrator.py` pre-plans N missions upfront from the captured initial state, samples each as `classical`/`single_ring`/`rearrange` at 40/40/20 weights, writes `metadata.json` with `goal_prompt`, `initial_state`, `target_state`, and the deterministic `solver_moves` (reference action sequence from a classical Hanoi BFS solver). The UR5e executes each mission with blended waypoints and per-ring grasp offsets.

### Stage 2 — Auto-labeling (SAM2 detection → graph)
Separate offline step that produces the entire `annotations/` tree. **Hanoi is fully automatic in v3; Desktop currently uses manual + SAM2-assisted labeling.** The Hanoi auto-labeler ships inside this dataset under `tools/hanoi_pipeline/` (so users cloning the dataset can reproduce or extend it):

```bash
python tools/hanoi_pipeline/scripts/hanoi/auto_label.py <session_dir>
```

Per-frame algorithm (Hanoi):
1. **Ring detection.** HSV range + color-specific mask → largest connected blob → bbox per ring.
2. **SAM2 segmentation.** Run SAM2 with (bbox + centroid point) prompt on each ring. The Hanoi-fine-tuned checkpoint is auto-loaded if present (`checkpoints/sam2_hanoi_ft.pt`); otherwise falls back to vanilla `sam2.1_hiera_base_plus`.
3. **256-D embedding.** Masked average-pool of SAM2's vision_features spatial grid over each ring mask.
4. **Depth backprojection.** Masked pixels → (u, v) + depth → 3D point cloud in camera frame; centroid used as the node position.

Per-episode algorithm:
5. **Grasp-interval detection.** Read `robot_states.npy[:, 12]` (Robotiq 2F-85 gripper position, 0-255). Find the lowest stable plateau above the fully-open cutoff (baseline ≈ pre-grasp width), threshold at baseline+10, morphologically close to bridge single-frame glitches, yielding `[(start, end, ring_id)]` intervals — one per move.
6. **Symbolic state unroll.** Starting from `initial_state`, apply `solver_moves[i]` after each interval closes, marking the moved ring as `held=True` during the interval and recording the resulting per-frame `constraints` / `visibility` / `held` dicts as deltas in `frame_states`. **No per-frame ring re-identification is needed**; the move plan is ground truth.

### Stage 3 — Verification / correction (optional)
Browser UI over labeled episodes — live in the **source repo** ([GitHub](https://github.com/ChangChrisLiu/gnn-world-model)), not bundled with the dataset because it's a full React app not just a Python module:

```bash
# from the source repo:
bash scripts/run_annotator.sh --hanoi     # or --desktop
# → open http://localhost:8000
```

Per-frame bbox / point / brush / eraser / polygon editing. Save writes back to the same `annotations/side_masks/*.npz`; format is identical pre- and post-verification, so downstream loaders are unaffected. The only module from the annotator that's bundled here is `tools/hanoi_pipeline/src/annotator/labeling_server.py` (the SAM2 backend — reused by `infer_graph_from_frame.py` at inference time).

### Stage 4 — SAM2 FT retraining (closes the loop)
After enough verified frames accumulate, retrain the SAM2 decoder+prompt_encoder on them. The training harness itself lives in the **source repo** ([GitHub](https://github.com/ChangChrisLiu/gnn-world-model)):

```bash
# from the source repo:
python scripts/sam2_finetune/collect_hanoi_samples.py   # pull (RGB, mask, bbox) triples
python scripts/sam2_finetune/train.py                   # fine-tune, save sam2_<domain>_ft.pt
```

The resulting `sam2_hanoi_ft.pt` goes at `tools/hanoi_pipeline/checkpoints/sam2_hanoi_ft.pt` (alongside the one already published here). `auto_label.py` and `HanoiGraphInferer()` both auto-select the checkpoint via that path on their next run.

## SAM2 models used in this dataset

Two checkpoints are in play, both distributed by this repo under `tools/hanoi_pipeline/checkpoints/` (also available from the SAM2 repo):

| File | Size | What it contains | When it's used |
|---|---|---|---|
| `sam2.1_hiera_base_plus.pt` (Meta AI) | ~320 MB | Full SAM2 model — image encoder + prompt encoder + mask decoder | Loaded as the base. Frozen during fine-tuning and inference |
| `sam2_hanoi_ft.pt` (this dataset) | ~16 MB | **Decoder + prompt_encoder only** — fine-tuned weights | Auto-loaded when present; overrides the base decoder/prompt_encoder |

The 16 MB FT checkpoint is small because the **image encoder stays frozen at the base SAM2 weights**. Training data: ~800 (image, bbox, ground-truth-mask) triples pulled from manually-corrected Hanoi episodes. Per-ring validation IoU (cross-episode held-out solve):

| Ring | Vanilla SAM2 base | Hanoi-FT | Δ |
|---|---|---|---|
| ring_1 (red) | 0.786 | 0.851 | +6.5 pp |
| ring_2 (yellow) | 0.803 | 0.842 | +3.9 pp |
| ring_3 (green) | 0.814 | 0.854 | +4.0 pp |
| ring_4 (blue) | 0.794 | 0.846 | +5.2 pp |
| **macro mean** | **0.799** | **0.848** | **+4.9 pp** |

Biggest gains are on partially-gripper-occluded rings where vanilla SAM2 tended to oversegment onto the gripper finger.

**Usage in the world-model prediction loop.** At inference time you don't need to run the full `auto_label.py` pipeline. Use the provided single-frame inferer:

```python
from tools.hanoi_pipeline.infer_graph_from_frame import HanoiGraphInferer

inferer = HanoiGraphInferer()        # loads base + FT once
result = inferer(rgb_image, depth=depth_image)

graph      = result["graph"]         # side_graph.json schema
masks      = result["masks"]         # {ring_1..ring_4: (H, W) uint8}
embeddings = result["embeddings"]    # {ring_1..ring_4: (256,) float32}
depth_info = result["depth_info"]    # flat-keyed 3D bundle (empty if depth=None)
states     = result["ring_states"]   # {ring_id: RingState(peg, stack_index)}
```

This returns the **same schema** as the offline pipeline's per-frame output, so the PyG loaders work identically on both sources. Override the checkpoint via `SAM2_FINETUNE_CKPT=<path>`; set to empty string to force vanilla SAM2.

## Desktop Disassembly Domain

### Components (9 types)

Eight product types + one robot agent. Multiple instances (e.g. `ram_1`, `ram_2`) share the same 10-D type encoding and are disambiguated by SAM2 embedding + 3D position.

| Index | Type | Color | Notes |
|---|---|---|---|
| 0 | `cpu_fan` | #FF6B6B | Always visible at start |
| 1 | `cpu_bracket` | #4ECDC4 | Hidden at start (under fan) |
| 2 | `cpu` | #45B7D1 | Hidden at start |
| 3 | `ram_clip` | #96CEB4 | Multi-instance |
| 4 | `ram` | #FFEAA7 | Multi-instance |
| 5 | `connector` | #DDA0DD | Multi-instance |
| 6 | `graphic_card` | #FF8C42 | Always visible |
| 7 | `motherboard` | #8B5CF6 | Always visible (base) |
| 8 | `robot` | #F5F5F5 | Agent node (stored separately in `side_robot/`) |

### Sparse constraint edges

Directed prerequisite relations — `A -> B` means "A must be removed before B can be removed":

```
cpu_fan      -> cpu_bracket         (fan covers bracket)
cpu_fan      -> motherboard
cpu_bracket  -> cpu
cpu_bracket  -> motherboard
cpu          -> motherboard
ram_N        -> motherboard
ram_clip_N   -> motherboard
ram_clip_N   -> ram_M               (user pairs manually)
connector_N  -> motherboard
graphic_card -> motherboard
```

Typical episode has 10-15 product nodes and 10-14 stored directed edges.

### Node feature layout (270-D)

```
[0   : 256]   SAM2 embedding (256)       — masked avg pool over vision_features
[256 : 259]   3D position (3)            — centroid in camera frame (meters)
[259 : 269]   type encoding (10)         — fixed 10-D vector from
                                            config/type_encoding_<method>.yaml
                                            (shared across domains)
[269]         visibility (1)             — 1 if visible this frame, else 0
```

Total: **270-D**. The 10-D type slot is a deterministic encoding (NOT trained) — see "Fixed 10-D type encoding — how it's made" below.

### Available Desktop episodes

| Session / Episode | Labeled frames | Goal |
|---|---|---|
| `session_0408_162129/episode_00` | 346 | `cpu_fan` |
| `session_0410_125013/episode_00` | 473 | `cpu_fan` |
| `session_0410_125013/episode_01` | 525 | `graphic_card` |

Total: **1344 frames**.

## Tower of Hanoi Domain

### Components (4 types) — rings only, no robot node in v1

Hanoi episodes use native ring IDs (`ring_1` .. `ring_4`) in `components` and as npz keys — **no desktop-proxy remapping, and no robot node in v1**. `type_vocab` is `["ring_1", "ring_2", "ring_3", "ring_4"]` (length 4). Robot segmentation is deferred; `side_robot/*.npz` is zero-filled per frame for format uniformity but never becomes a graph node.

**Note on V2 vs V3 for Hanoi.** V2 (`with_robot` — robot as graph node) requires a labeled robot mask/embedding and is therefore **Desktop-only in v1**. V3 (`with_robot_state` / `with_robot_action`) uses the 13-D `robot_states.npy` trace, which IS recorded for Hanoi too — so V3 loaders work for both domains.

| ID | Color | Disk size | Role |
|---|---|---|---|
| `ring_1` | red (#E63946) | 32 mm | Smallest |
| `ring_2` | yellow (#F1C40F) | 42 mm | — |
| `ring_3` | green (#2ECC71) | 52 mm | — |
| `ring_4` | blue (#2E86DE) | 62 mm | Largest |

Mask `.npz` files carry the literal keys `ring_1`, `ring_2`, `ring_3`, `ring_4`. No robot in `type_vocab`, no robot edges, no robot node appended at load time.

### Mission kinds (40 / 40 / 20 sampling)

| Kind | Weight | Prompt template | Target |
|---|---|---|---|
| `classical` | 0.40 | `"Solve the puzzle: stack all rings on peg X"` | All 4 rings stacked in size order on one peg |
| `single_ring` | 0.40 | `"Move the <color> ring to peg X"` | One designated ring moved; others untouched |
| `rearrange` | 0.20 | `"Rearrange: red on peg A, green on peg B, ..."` | Uniformly sampled valid (larger-under-smaller) configuration |

Every Hanoi `metadata.json` records `mission_kind`, `goal_prompt`, `initial_state`, `target_state`, and `solver_moves` (the reference action sequence from the classical-Hanoi solver, one entry per pickup/release pair).

### Structural edges (static, always 6)

The 6 smaller → larger directed pairs are stored verbatim in `side_graph.json`:

```
ring_1 -> ring_2     ring_1 -> ring_3     ring_1 -> ring_4
                     ring_2 -> ring_3     ring_2 -> ring_4
                                          ring_3 -> ring_4
```

At PyG load time the loader expands to **4 × 3 = 12** fully-connected directed edges. The reverse (larger → smaller) direction carries the same `has_constraint` / `is_locked` but flipped `src_blocks_dst`.

### Per-frame `is_locked` semantics

`is_locked = 1` on edge `(A, B)` **iff A is currently the immediately-stacked ring on top of B on the same peg** (adjacent in the peg-stack with A above B). Every other pair — non-adjacent on the same peg, on different pegs, or with either ring in transit — gets `is_locked = 0`. This is strictly "physical stacking right now," not "A must move before B."

### Held-ring rule (captures "constraint broken during transit")

When the robot holds a ring (gripper closed between grasp and release of that move), the ring is in transit and no longer touches any other ring. The auto-labeler flags `held = 1` for that ring on every held frame, and **every edge touching it gets `is_locked = 0`** — the constraint is physically broken mid-move. On release, the new adjacency emerges and that edge flips back to `is_locked = 1`.

Implementation: `auto_label.py` reads `robot_states.npy[:, 12]` (gripper position, Robotiq 2F-85, 0-255) and detects grasp intervals via baseline-mode thresholding (estimate "resting open" mode, threshold at baseline + margin, binary-close morphologically to bridge single-frame glitches). It then zips the resulting intervals with `solver_moves` **in order** — the k-th grasp interval is assigned to the k-th move. Validated on ep_00 (1 move, 1 interval), ep_01 (15 moves, 15 intervals), ep_02 (1 move, 1 interval). Per-frame held deltas are recorded as `frame_states[f].held = {ring_id: True|False}`.

### Rule 2 — "larger must never sit on smaller"

Encoded **without a new feature** via the edge's existing `src_blocks_dst` bit:

| Edge direction | `src_blocks_dst` | Meaning |
|---|---|---|
| smaller → larger (e.g. `ring_1 -> ring_3`) | 1 | **Legal** — smaller may rest on larger |
| larger → smaller (e.g. `ring_3 -> ring_1`) | 0 | **Illegal** — larger may not rest on smaller |

Three dimension-preserving ways the world model can respect Rule 2:

| Method | Where | One-liner | Guarantee |
|---|---|---|---|
| Training loss | objective | `λ * (pred_is_locked * (1 - src_blocks_dst)).sum()` | Soft (shapes distribution) |
| Rollout mask | inference | Reject any predicted `is_locked = 1` where `src_blocks_dst = 0` | Hard (eliminates illegal) |
| Dataset invariant | this spec | `is_locked` is never 1 on a larger→smaller edge in any training frame | Hard (on training distribution) |

### Node feature layout (270-D)

```
[0   : 256]   SAM2 embedding (256)
[256 : 259]   3D position (3)
[259 : 269]   type encoding (10)         — fixed 10-D vector from
                                            config/type_encoding_<method>.yaml
                                            (shared with Desktop)
[269]         visibility (1)
```

Total: **270-D** — identical to Desktop. The 10-D encoding is domain-independent; unknown/unlisted types encode to a zero vector.

### Mission metadata saved per episode

Every Hanoi `side_graph.json` carries `goal_prompt`, `mission_kind`, and `target_state` in addition to the fields shared with Desktop. Per-frame transitions (grasps, releases, re-stacks) are recorded as deltas in `frame_states[f]` with `constraints`, `visibility`, **and** `held` sub-dicts.

### Hanoi episodes available

| Session | Episodes | Frames | Collection mode | Notes |
|---|---|---|---|---|
| `hanoi/session_hanoi_0415_190808` | 3 | 7,479 | manual + teleop | Initial Hanoi pilot: 1 × classical 15-move solve + 2 × single-ring moves |
| `hanoi/session_hanoi_0417_133613` | 7 | 10,968 | autonomous orchestrator | Initial 4-stack on peg B, 40/40/20 mission mix, 1-10 moves per episode |
| `hanoi/session_hanoi_0417_144403` | 20 | 30,942 | autonomous orchestrator | Initial 4-stack on peg A, 40/40/20 mission mix, 1-10 moves per episode |
| `hanoi/session_hanoi_0417_164816` | 20 | 64,185 | autonomous orchestrator | Initial 4-stack on peg C, minimum 3 moves per episode (no upper cap). `episode_18.zip` and `episode_19.zip` are stored as **zip archives** (see note below). |

Total across all Hanoi sessions: **50 episodes, 113,574 frames**. Each `episode_XX/metadata.json` records the exact `mission_kind`, `goal_prompt`, `initial_state`, `target_state`, and `solver_moves` for that episode. All autonomous sessions are produced by `scripts/hanoi/orchestrator.py`, which pre-plans all N missions upfront from the captured initial state, resamples any mission exceeding the per-episode move cap, and records a deterministic solver reference trajectory for each accepted mission.

**Zipped episodes.** The last two episodes of `session_hanoi_0417_164816` (`episode_18.zip`, `episode_19.zip`) are stored as uncompressed (`zip -0`) archives rather than expanded directory trees. HuggingFace datasets have a hard cap of 1 million files per repository, and expanding these two episodes would have exceeded it. Extract before use:

```bash
cd hanoi/session_hanoi_0417_164816
unzip episode_18.zip   # → episode_18/
unzip episode_19.zip   # → episode_19/
```

Once unzipped, the on-disk layout is identical to every other `episode_XX/` directory in this dataset (same `metadata.json`, `robot_states.npy`, `side/`, `wrist/`, `annotations/` tree, loadable by the exact same PyG loaders below). All other episodes in the dataset are stored as expanded directories and require no pre-processing.

### Graph generation for Hanoi (reference)

The full pipeline that produced every `annotations/` tree above is checked in under `tools/hanoi_pipeline/` in this repo. For the pipeline overview, algorithm details, and SAM2 checkpoint stats see the **Pipeline** and **SAM2 models** sections above. For the single-frame runtime inferer (use it inside a world-model prediction loop to turn a predicted RGB back into a graph), see `tools/hanoi_pipeline/infer_graph_from_frame.py` and `tools/hanoi_pipeline/README.md`.

### Per-frame graph retrieval — how it works (important)

**Every frame in every episode has its own distinct graph.** The dataset stores them as a (structural skeleton + per-frame deltas) decomposition rather than N JSON files per episode, because the skeleton is the same every frame and the deltas are small. This cuts ~6000× disk-space per episode while losing zero information — the loader reconstructs each frame's full graph on demand.

Where each piece of a per-frame graph lives:

| Component of the frame-T graph | File |
|---|---|
| Node list (which rings exist) + structural edges (smaller→larger pairs) | `annotations/side_graph.json` → `components`, `edges` (shared across all frames) |
| `is_locked` / `visibility` / `held` **as of frame T** | `annotations/side_graph.json` → `frame_states` (delta-encoded up to T) |
| SAM2 mask of each ring at frame T | `annotations/side_masks/frame_TTTTTT.npz` |
| 256-D SAM2 embedding at frame T | `annotations/side_embeddings/frame_TTTTTT.npz` |
| 3D position (centroid) + bbox + depth-valid flag at frame T | `annotations/side_depth_info/frame_TTTTTT.npz` |
| Robot state at frame T | `robot_states.npy[T]` (13-D) |

The PyG loader combines these into a `torch_geometric.data.Data` object for exactly that frame — node features differ per frame (new embeddings + new 3D positions + new visibility flags), and edge features differ per frame (`is_locked` bits flip as rings are stacked / unstacked / held mid-transit).

**To get a distinct graph for every labeled frame in an episode:** use the `list_all_frame_graphs` helper below, or run `scripts/materialize_per_frame_graphs.py` to materialize them as individual `.pt` (and optional `.json`) files on disk.

#### Where edge-feature transitions live

The 3-D `edge_attr` vector is `[has_constraint, is_locked, src_blocks_dst]`. Of these, **only `is_locked` changes over time** — it flips when a ring lifts off / lands on another ring (or enters/exits the held state mid-transit). `has_constraint` and `src_blocks_dst` are static per edge.

Every transition of `is_locked` (and every transition of `held`) is recorded as a **delta** in `side_graph.json` under `frame_states`. The key is the frame index at which the transition happens; the value lists exactly which entries changed. Example from a real Hanoi single-move episode:

```jsonc
"frame_states": {
  "0":   {"constraints": {"ring_1->ring_2": true,  "ring_2->ring_3": true,
                          "ring_3->ring_4": true}},                // initial stack
  "134": {"constraints": {"ring_1->ring_2": false},                // ring_1 lifted OFF ring_2
          "held":        {"ring_1": true}},                        // ring_1 now in transit
  "278": {"constraints": {"ring_1->ring_3": true},                 // ring_1 placed on ring_3
          "held":        {"ring_1": false}}
}
```

The loader's `resolve_frame_state(graph_json, T)` walks `frame_states` in ascending key order up to `T`, applies every listed constraint/held delta, and returns the **resolved state at frame T**. That resolved state then populates `edge_attr[:, 1]` (the `is_locked` column) and the `held` flags that zero out edges touching rings in transit. So for frame 200 in the example above, `ring_1->ring_2` is unlocked *and* every other edge touching `ring_1` is also unlocked (held-ring rule), whereas `ring_3->ring_4` is still locked (never changed).

Bottom line: there's no separate edge-feature file per frame — the transitions are packed into one delta dict in `side_graph.json`, and the loader replays them to give you the exact `edge_attr` for whichever frame you ask for.

## Shared: PyG edge feature semantics (3-D, both domains)

`edge_attr[k] = [has_constraint, is_locked, src_blocks_dst]`

| `has_constraint` | `is_locked` | `src_blocks_dst` | Meaning |
|---|---|---|---|
| 0 | 0 | 0 | No physical constraint — message passing only. Used for: robot ↔ anything; Hanoi larger → smaller (non-edge at the pair level) |
| 1 | 1 | 1 | Constraint active, src is the blocker (physical Desktop) / src rests on top (physical Hanoi) |
| 1 | 1 | 0 | Same pair, reverse direction — src is the blocked / src is underneath |
| 1 | 0 | 1 | Constraint released, src was the blocker / legal rest direction with no contact right now |
| 1 | 0 | 0 | Same released pair, reverse direction |

**Symmetry invariants:** `has_constraint` and `is_locked` are symmetric per unordered pair (same value for `(i, j)` and `(j, i)`). `src_blocks_dst` flips between the two directions. Robot ↔ anything edges are always `[0, 0, 0]`.

## Shared: Fixed 10-D type encoding — how it's made

Across both domains the component-type universe is **13 types** (the two vocabularies unioned):

```
cpu_fan, cpu_bracket, cpu, ram_clip, ram, connector, graphic_card, motherboard,
ring_1, ring_2, ring_3, ring_4, robot
```

Each type is assigned a **fixed 10-D vector**. The encoding is **NOT trained** — it is a deterministic lookup read from a YAML at load time, so any consumer of the dataset gets the exact same node features bit-for-bit. Two methods are provided; both YAMLs live at the dataset repo root alongside the session directories:

| Method | YAML file | How vectors are built | Semantic structure |
|---|---|---|---|
| `random` | `config/type_encoding_random.yaml` | `numpy.random.default_rng(42)` unit-norm 10-vectors, one per type | None — vectors are orthogonal-ish noise |
| `clip` | `config/type_encoding_clip.yaml` | CLIP ViT-B/32 text embedding of a humanised prompt (e.g. `"a CPU fan"`, `"a small red ring"`) → PCA to 10 → unit-normalise | Related types cluster (the four rings are close; the fan/bracket/cpu cluster is tight) |

**Unknown type → 10-D zero vector.** If a component's `type` is not in the YAML, the loader returns `np.zeros(10, dtype=np.float32)` for that slot. This keeps node dim at 270 regardless of vocabulary drift.

**To reproduce or extend:** download whichever YAML you want from the dataset repo root, load it with `yaml.safe_load`, and look up each component's type. The loader code below shows the full pattern.

## Shared: PyG loader — self-contained Python

### Prerequisites

```bash
pip install torch numpy torch_geometric pillow pyyaml
```

### Save as `gnn_world_model_loader.py`

The key design property: `node_dim = 256 + 3 + 10 + 1 = 270` for both domains. The 10-D type slot comes from the fixed YAML encoding (loaded once), so there's no domain branching — Desktop, Hanoi, and any future vocabulary all produce 270-D nodes.

```python
import json
from dataclasses import dataclass
from functools import lru_cache
from pathlib import Path
from typing import Dict, List, Optional
import numpy as np
import torch
import yaml
from torch_geometric.data import Data

# ---------- constants ----------
TYPE_ENCODING_DIM = 10          # fixed, domain-independent
SAM2_EMB_DIM = 256
POS_DIM = 3
VIS_DIM = 1
NODE_DIM = SAM2_EMB_DIM + POS_DIM + TYPE_ENCODING_DIM + VIS_DIM   # = 270
ROBOT_STATE_DIM = 13            # [j0..j5, tcp_x, tcp_y, tcp_z, tcp_rx, tcp_ry, tcp_rz, gripper_pos]


# ---------- fixed type encoding ----------
# Download once from the dataset repo root:
#   config/type_encoding_random.yaml   (seeded numpy unit vectors, seed=42)
#   config/type_encoding_clip.yaml     (CLIP ViT-B/32 text → PCA(10) → unit-norm)
# Point TYPE_ENCODING_ROOT at wherever you saved them.
TYPE_ENCODING_ROOT = Path("./config")


@lru_cache(maxsize=4)
def load_type_encoding(encoding_method: str = "random") -> Dict[str, np.ndarray]:
    """Load the fixed 10-D per-type encoding from YAML. Cached across calls."""
    path = TYPE_ENCODING_ROOT / f"type_encoding_{encoding_method}.yaml"
    with open(path) as f:
        raw = yaml.safe_load(f)
    return {k: np.asarray(v, dtype=np.float32) for k, v in raw.items()}


def type_encode(comp_type: str, encoding_method: str = "random") -> np.ndarray:
    """Return 10-D vector for `comp_type`; zeros for unknown types."""
    table = load_type_encoding(encoding_method)
    vec = table.get(comp_type)
    if vec is None:
        return np.zeros(TYPE_ENCODING_DIM, dtype=np.float32)
    return vec.astype(np.float32)


# ---------- file helpers ----------
def list_labeled_frames(episode_dir: Path) -> List[int]:
    mask_dir = episode_dir / "annotations" / "side_masks"
    if not mask_dir.exists():
        return []
    frames = []
    for p in mask_dir.glob("frame_*.npz"):
        try:
            frames.append(int(p.stem.split("_")[1]))
        except (ValueError, IndexError):
            continue
    return sorted(frames)


def resolve_frame_state(graph_json: dict, frame_idx: int):
    constraints, visibility = {}, {}
    for c in graph_json["components"]:
        visibility[c["id"]] = True
    for e in graph_json["edges"]:
        constraints[f"{e['src']}->{e['dst']}"] = True
    fs_dict = graph_json.get("frame_states", {})
    for f in sorted([int(k) for k in fs_dict]):
        if f > frame_idx:
            break
        fs = fs_dict[str(f)]
        for k, v in fs.get("constraints", {}).items():
            constraints[k] = v
        for k, v in fs.get("visibility", {}).items():
            visibility[k] = v
    return constraints, visibility


@dataclass
class FrameData:
    graph: dict
    masks: dict
    embeddings: dict
    depth_info: dict
    robot: Optional[dict]
    constraints: dict
    visibility: dict


def load_frame_data(episode_dir, frame_idx):
    anno = Path(episode_dir) / "annotations"
    with open(anno / "side_graph.json") as f:
        graph = json.load(f)
    def _npz(p):
        if not p.exists(): return {}
        d = np.load(p)
        return {k: d[k] for k in d.files}
    masks = _npz(anno / "side_masks" / f"frame_{frame_idx:06d}.npz")
    embeddings = _npz(anno / "side_embeddings" / f"frame_{frame_idx:06d}.npz")
    depth_info = _npz(anno / "side_depth_info" / f"frame_{frame_idx:06d}.npz")
    robot = None
    rp = anno / "side_robot" / f"frame_{frame_idx:06d}.npz"
    if rp.exists():
        r = np.load(rp)
        if r["visible"][0] == 1:
            robot = {k: r[k] for k in r.files}
    constraints, visibility = resolve_frame_state(graph, frame_idx)
    return FrameData(graph, masks, embeddings, depth_info, robot, constraints, visibility)


def _build_product_node_features(nodes, fd, encoding_method):
    feats = []
    for node in nodes:
        cid = node["id"]
        emb = fd.embeddings.get(cid, np.zeros(SAM2_EMB_DIM, dtype=np.float32))
        dvk = f"{cid}_depth_valid"; ck = f"{cid}_centroid"
        if dvk in fd.depth_info and int(fd.depth_info[dvk][0]) == 1:
            pos = fd.depth_info[ck].astype(np.float32)
        else:
            pos = np.zeros(POS_DIM, dtype=np.float32)
        vis = 1.0 if fd.visibility.get(cid, True) else 0.0
        if vis == 0.0:
            emb = np.zeros(SAM2_EMB_DIM, dtype=np.float32)
            pos = np.zeros(POS_DIM, dtype=np.float32)
        feats.append(np.concatenate([
            emb.astype(np.float32),
            pos,
            type_encode(node["type"], encoding_method),
            np.array([vis], dtype=np.float32),
        ]))
    if not feats:
        return torch.empty((0, NODE_DIM), dtype=torch.float32)
    return torch.tensor(np.stack(feats), dtype=torch.float32)


def _build_product_edges(nodes, graph, fd):
    N = len(nodes)
    constraint_set = {(e["src"], e["dst"]) for e in graph["edges"]}
    pair_forward = {frozenset([s, d]): (s, d) for s, d in constraint_set}
    src_idx, dst_idx, edge_attr = [], [], []
    for i in range(N):
        for j in range(N):
            if i == j: continue
            src_id, dst_id = nodes[i]["id"], nodes[j]["id"]
            src_idx.append(i); dst_idx.append(j)
            key = frozenset([src_id, dst_id])
            if key in pair_forward:
                fwd = pair_forward[key]
                is_locked = fd.constraints.get(f"{fwd[0]}->{fwd[1]}", True)
                sb = 1.0 if src_id == fwd[0] else 0.0
                edge_attr.append([1.0, 1.0 if is_locked else 0.0, sb])
            else:
                edge_attr.append([0.0, 0.0, 0.0])
    return src_idx, dst_idx, edge_attr


# ---------- 1) products-only (Option 1: direct graph encoding) ----------
def load_pyg_frame_products_only(episode_dir, frame_idx, encoding_method: str = "random"):
    fd = load_frame_data(episode_dir, frame_idx)
    nodes = fd.graph["components"]
    x = _build_product_node_features(nodes, fd, encoding_method)
    src, dst, ea = _build_product_edges(nodes, fd.graph, fd)
    return Data(
        x=x,
        edge_index=torch.tensor([src, dst], dtype=torch.long),
        edge_attr=torch.tensor(ea, dtype=torch.float32),
        y=torch.tensor([frame_idx], dtype=torch.long),
        num_nodes=len(nodes),
    )


# ---------- 2) V2 ablation: robot as graph NODE (Desktop only) ----------
def load_pyg_frame_with_robot(episode_dir, frame_idx, encoding_method: str = "random"):
    fd = load_frame_data(episode_dir, frame_idx)
    # Hanoi has no robot mask/embedding in v1 → fall back to products-only.
    if fd.robot is None:
        return load_pyg_frame_products_only(episode_dir, frame_idx, encoding_method)

    products = fd.graph["components"]
    N_prod = len(products); N = N_prod + 1

    x_prod = _build_product_node_features(products, fd, encoding_method)
    robot_emb = fd.robot["embedding"].astype(np.float32)
    robot_pos = (fd.robot["centroid"].astype(np.float32)
                 if int(fd.robot["depth_valid"][0]) == 1
                 else np.zeros(POS_DIM, dtype=np.float32))
    robot_feat = np.concatenate([
        robot_emb, robot_pos,
        type_encode("robot", encoding_method),
        np.array([1.0], dtype=np.float32),
    ])
    x = torch.cat([x_prod, torch.tensor(robot_feat, dtype=torch.float32).unsqueeze(0)], dim=0)

    src, dst, ea = _build_product_edges(products, fd.graph, fd)
    robot_idx = N_prod
    for i in range(N_prod):
        src.append(robot_idx); dst.append(i); ea.append([0.0, 0.0, 0.0])
        src.append(i); dst.append(robot_idx); ea.append([0.0, 0.0, 0.0])

    data = Data(
        x=x,
        edge_index=torch.tensor([src, dst], dtype=torch.long),
        edge_attr=torch.tensor(ea, dtype=torch.float32),
        y=torch.tensor([frame_idx], dtype=torch.long),
        num_nodes=N,
    )
    data.robot_point_cloud = torch.tensor(fd.robot["point_cloud"], dtype=torch.float32)
    data.robot_pixel_coords = torch.tensor(fd.robot["pixel_coords"], dtype=torch.int32)
    data.robot_mask = torch.tensor(fd.robot["mask"], dtype=torch.uint8)
    return data


# ---------- 3) V3 recommended: products graph + robot_state side-tensor ----------
def load_pyg_frame_with_robot_state(episode_dir, frame_idx, encoding_method: str = "random"):
    data = load_pyg_frame_products_only(episode_dir, frame_idx, encoding_method)
    robot_states = np.load(Path(episode_dir) / "robot_states.npy")   # (T, 13) float32
    rs = robot_states[frame_idx].astype(np.float32)                  # 13-D
    data.robot_state = torch.tensor(rs, dtype=torch.float32)
    return data


# ---------- 4) V3 action-conditioned: + robot_action delta ----------
def load_pyg_frame_with_robot_action(episode_dir, frame_idx, encoding_method: str = "random"):
    data = load_pyg_frame_with_robot_state(episode_dir, frame_idx, encoding_method)
    robot_states = np.load(Path(episode_dir) / "robot_states.npy")   # (T, 13)
    T = robot_states.shape[0]
    if frame_idx + 1 < T:
        action = robot_states[frame_idx + 1] - robot_states[frame_idx]
    else:
        action = np.zeros(ROBOT_STATE_DIM, dtype=np.float32)
    data.robot_action = torch.tensor(action.astype(np.float32), dtype=torch.float32)
    return data


# ---------- 5) Generator: one distinct graph per labeled frame ----------
_VARIANTS = {
    "products_only":     load_pyg_frame_products_only,
    "with_robot":        load_pyg_frame_with_robot,
    "with_robot_state":  load_pyg_frame_with_robot_state,
    "with_robot_action": load_pyg_frame_with_robot_action,
}


def list_all_frame_graphs(
    episode_dir,
    variant: str = "with_robot_state",
    encoding_method: str = "random",
):
    """Yield (frame_idx, Data) for every labeled frame in an episode.

    Each `Data` object is the full per-frame graph (node features, edges,
    edge features, and any requested side tensors). Feature values and
    `is_locked` bits differ per frame as rings move / stack / get held.
    """
    if variant not in _VARIANTS:
        raise ValueError(f"variant must be one of {list(_VARIANTS)}, got {variant!r}")
    loader = _VARIANTS[variant]
    for f in list_labeled_frames(Path(episode_dir)):
        yield f, loader(episode_dir, f, encoding_method=encoding_method)
```

### Usage examples

All four loaders share the signature `(episode_dir, frame_idx, encoding_method="random")`. Swap `"random"` for `"clip"` to use the CLIP-derived encoding instead.

**Desktop V1** — 15 product nodes, 270-D features, fully-connected edges (15×14 = 210):

```python
from pathlib import Path
from gnn_world_model_loader import load_pyg_frame_products_only

episode = Path("session_0408_162129/episode_00")
data = load_pyg_frame_products_only(episode, frame_idx=42)
print(data)
# → Data(x=[15, 270], edge_index=[2, 210], edge_attr=[210, 3])
```

**Desktop V3 (recommended)** — same graph + 13-D robot_state side-tensor:

```python
from gnn_world_model_loader import load_pyg_frame_with_robot_state

data = load_pyg_frame_with_robot_state(episode, frame_idx=42)
print(data)
# → Data(x=[15, 270], edge_index=[2, 210], edge_attr=[210, 3], robot_state=[13])
```

**Desktop V3 action-conditioned** — adds 13-D delta for the next frame:

```python
from gnn_world_model_loader import load_pyg_frame_with_robot_action

data = load_pyg_frame_with_robot_action(episode, frame_idx=42)
# → Data(x=[15, 270], edge_index=[2, 210], edge_attr=[210, 3],
#         robot_state=[13], robot_action=[13])
```

**Hanoi V1** — 4 ring nodes, 270-D features, 12 fully-connected edges:

```python
episode = Path("hanoi/session_hanoi_0415_190808/episode_00")
data = load_pyg_frame_products_only(episode, frame_idx=250)
print(data)
# → Data(x=[4, 270], edge_index=[2, 12], edge_attr=[12, 3])
```

**Hanoi V3 (recommended)** — V3 works for Hanoi too because `robot_states.npy` is recorded for every episode:

```python
data = load_pyg_frame_with_robot_state(episode, frame_idx=250)
print(data)
# → Data(x=[4, 270], edge_index=[2, 12], edge_attr=[12, 3], robot_state=[13])
```

**V2 note.** `load_pyg_frame_with_robot` falls back to `load_pyg_frame_products_only` on Hanoi (no robot mask), so for Hanoi V1 and V2 return identical graphs. On Desktop V2 attaches the robot as a 16-th node (x shape becomes `[16, 270]`).

## How to use this dataset — full instructions

The sections below walk through every common task from scratch. All examples target the Hanoi subset (`hanoi/`), which is the more heavily instrumented of the two domains.

### Step 0 — Download and set up

```bash
pip install huggingface_hub torch torch_geometric numpy pyyaml opencv-python pillow

# Pull the whole dataset (~150 GB) — or use allow_patterns to slim it down
hf download ChangChrisLiu/GNN_Disassembly_WorldModel --repo-type dataset --local-dir ./gnn_world_model

# Or cherry-pick just a few Hanoi episodes:
hf download ChangChrisLiu/GNN_Disassembly_WorldModel --repo-type dataset \
    --include "hanoi/session_hanoi_0415_190808/episode_00/*" \
               "hanoi/session_hanoi_0415_190808/episode_00/**/*" \
               "config/type_encoding_*.yaml" \
    --local-dir ./gnn_world_model

cd gnn_world_model
```

Unzip the two zipped episodes (only `episode_18.zip` and `episode_19.zip` in `session_hanoi_0417_164816` are zipped; all others are expanded):

```bash
cd hanoi/session_hanoi_0417_164816
unzip episode_18.zip   # → episode_18/
unzip episode_19.zip   # → episode_19/
cd ../..
```

Save the loader code from the [PyG loader](#shared-pyg-loader--self-contained-python) section above as `gnn_world_model_loader.py` in the dataset root so `from gnn_world_model_loader import ...` resolves. The loader reads `./config/type_encoding_*.yaml`, so make sure both YAMLs are in place.

### Step 1 — Load one episode and inspect its per-frame graphs

Every labeled frame produces a distinct `torch_geometric.data.Data` object. The following script loads one Hanoi episode, picks a middle frame, shows the full graph, and iterates over the first few frames to demonstrate that `is_locked` bits change over time:

```python
from pathlib import Path
from gnn_world_model_loader import (
    load_pyg_frame_with_robot_state,
    list_labeled_frames,
    list_all_frame_graphs,
)

episode = Path("hanoi/session_hanoi_0415_190808/episode_00")

# 1a. All labeled frame indices for this episode
frames = list_labeled_frames(episode)
print(f"{len(frames)} labeled frames ({frames[0]} .. {frames[-1]})")

# 1b. Load one specific frame
frame_idx = frames[len(frames) // 2]
data = load_pyg_frame_with_robot_state(episode, frame_idx, encoding_method="random")
print(data)
# → Data(x=[4, 270], edge_index=[2, 12], edge_attr=[12, 3], robot_state=[13], ...)
print("is_locked  :", data.edge_attr[:, 1].tolist())
print("src_blocks :", data.edge_attr[:, 2].tolist())

# 1c. Iterate all frames — each Data carries that frame's exact state
for f, g in list_all_frame_graphs(episode, variant="with_robot_state"):
    locked = int(g.edge_attr[:, 1].sum().item())
    print(f"frame {f:6d}  locked_edges={locked}/12")
```

The `variant` argument picks which of the four loader signatures to use:
- `"products_only"` — graph alone (no robot info)
- `"with_robot"` — Desktop V2 (Hanoi falls back to products-only)
- `"with_robot_state"` — graph + 13-D `robot_state` side tensor (**recommended for both domains**)
- `"with_robot_action"` — also adds a 13-D `robot_action` (next-frame delta)

### Step 2 — Build a training DataLoader and train a GNN

Concatenate frames across any number of episodes into a plain list of `Data`, hand it to PyG's `DataLoader`, and you have batched mini-batches. This full training skeleton also shows the Rule-2 soft-compliance loss (discouraging the model from ever predicting `is_locked=1` on a larger→smaller edge):

```python
from pathlib import Path
from typing import List
import torch
import torch.nn.functional as F
from torch_geometric.data import Data
from torch_geometric.loader import DataLoader
from torch_geometric.nn import GATConv
from gnn_world_model_loader import (
    list_all_frame_graphs,
    NODE_DIM,          # = 270
    ROBOT_STATE_DIM,   # = 13
)

# 2a. Build the dataset — concatenate every frame of every selected episode.
def build_hanoi_dataset(roots: List[Path]) -> List[Data]:
    return [g for ep in roots for _, g in list_all_frame_graphs(ep, variant="with_robot_state")]

hanoi_root = Path("hanoi")
episodes = sorted(
    ep for sess in hanoi_root.glob("session_hanoi_*") for ep in sess.glob("episode_*") if ep.is_dir()
)
samples = build_hanoi_dataset(episodes[:5])      # first 5 episodes as a quick smoke-test
loader  = DataLoader(samples, batch_size=32, shuffle=True)

# 2b. A minimal GNN head that predicts per-edge `is_locked`.
class IsLockedPredictor(torch.nn.Module):
    def __init__(self, node_dim=NODE_DIM, edge_dim=3, hidden=128, robot_dim=ROBOT_STATE_DIM):
        super().__init__()
        self.gat1 = GATConv(node_dim + robot_dim, hidden, heads=4, concat=True, edge_dim=edge_dim)
        self.gat2 = GATConv(hidden * 4,            hidden, heads=1,             edge_dim=edge_dim)
        self.edge_head = torch.nn.Sequential(
            torch.nn.Linear(2 * hidden, hidden), torch.nn.ReLU(),
            torch.nn.Linear(hidden, 1),
        )

    def forward(self, data: Data):
        # PyG concatenates 1-D per-graph attrs along dim 0 (default __cat_dim__ = 0),
        # so after batching data.robot_state has shape [num_graphs * 13].  Reshape to
        # [num_graphs, 13] and broadcast to every node via data.batch.
        robot = data.robot_state.view(-1, ROBOT_STATE_DIM)[data.batch]   # [N_total, 13]
        x = torch.cat([data.x, robot], dim=-1)
        x = self.gat1(x, data.edge_index, data.edge_attr).relu()
        x = self.gat2(x, data.edge_index, data.edge_attr)
        src, dst = data.edge_index
        return self.edge_head(torch.cat([x[src], x[dst]], dim=-1)).squeeze(-1)

# 2c. Training loop with BCE loss on `is_locked` plus a Rule-2 compliance term.
device = "cuda" if torch.cuda.is_available() else "cpu"
model = IsLockedPredictor().to(device)
opt   = torch.optim.AdamW(model.parameters(), lr=3e-4)

for epoch in range(3):
    for batch in loader:
        batch  = batch.to(device)
        logits = model(batch)                                   # [E_total]
        target = batch.edge_attr[:, 1]                          # ground-truth is_locked
        ce     = F.binary_cross_entropy_with_logits(logits, target)
        # Rule-2: penalise predicting locked=1 on an illegal (larger→smaller) edge.
        legal  = batch.edge_attr[:, 2]
        rule2  = (torch.sigmoid(logits) * (1 - legal)).mean()
        loss   = ce + 0.1 * rule2
        opt.zero_grad(); loss.backward(); opt.step()
    print(f"epoch {epoch}  ce={ce.item():.4f}  rule2={rule2.item():.4f}")
```

### Step 3 — Inference: turn a predicted RGB into a graph

When your world model has generated a future RGB (and optionally a matching depth), use the **single-frame inferer** to produce the same graph schema you trained on. It loads SAM2 base plus the Hanoi-FT decoder once, then maps an image to `{graph, masks, embeddings, depth_info, ring_states}` with no temporal context required.

```python
import cv2
import numpy as np
from tools.hanoi_pipeline.infer_graph_from_frame import HanoiGraphInferer

inferer = HanoiGraphInferer()        # loads SAM2 base + sam2_hanoi_ft.pt

# A real frame from the dataset is a fine sanity-check input.
rgb   = cv2.cvtColor(cv2.imread(
    "hanoi/session_hanoi_0415_190808/episode_00/side/rgb/frame_000100.png"),
    cv2.COLOR_BGR2RGB)
depth = np.load(
    "hanoi/session_hanoi_0415_190808/episode_00/side/depth/frame_000100.npy")  # uint16 mm

result = inferer(rgb, depth=depth)

# Five-field output. Schema matches the offline pipeline exactly.
# result["graph"]       — same dict as side_graph.json (frame_states empty)
# result["masks"]       — {"ring_1".."ring_4": (H, W) uint8}
# result["embeddings"]  — {"ring_1".."ring_4": (256,) float32}
# result["depth_info"]  — flat-keyed 3D bundle (centroids, point clouds, bboxes)
# result["ring_states"] — {"ring_id": RingState(peg, stack_index)}
```

Convert the result to a PyG `Data` that matches the training format:

```python
import torch
from gnn_world_model_loader import (
    NODE_DIM, SAM2_EMB_DIM, POS_DIM, type_encode,
)

components = result["graph"]["components"]
feats = []
for c in components:
    cid = c["id"]
    emb = result["embeddings"][cid].astype(np.float32)
    centroid_key = f"{cid}_centroid"
    pos = (result["depth_info"][centroid_key].astype(np.float32)
           if centroid_key in result["depth_info"]
           else np.zeros(POS_DIM, dtype=np.float32))
    feats.append(np.concatenate([
        emb, pos, type_encode(c["type"]), np.array([1.0], dtype=np.float32),
    ]))
x = torch.tensor(np.stack(feats), dtype=torch.float32)   # [4, 270] for Hanoi

# Fully-connected N×(N-1) edges with has_constraint / src_blocks_dst — reuse the
# same _build_product_edges helper from the loader module that the training
# pipeline uses, or expand manually from result["graph"]["edges"].
```

The same `HanoiGraphInferer` can be pointed at a different fine-tuned checkpoint via the `SAM2_FINETUNE_CKPT` environment variable, or set to the empty string to force vanilla SAM2.

### Step 4 — Auto-label a freshly-captured session

If you collect new Hanoi data using the source repo's orchestrator, run the bundled auto-labeler to produce the full `annotations/` tree. That's all that's needed — the PyG loaders above then work on the new session unchanged.

```bash
# (optional — in the source repo https://github.com/ChangChrisLiu/gnn-world-model)
# Collect a fresh session:
#   python scripts/hanoi/orchestrator.py --n-episodes 20 --data-root /path/to/sessions

# Auto-label the captured session — this is what ships with the dataset:
python tools/hanoi_pipeline/scripts/hanoi/auto_label.py \
    /path/to/sessions/session_hanoi_<date>_<time>/
```

`auto_label.py` produces, for every episode:

- `annotations/side_masks/frame_XXXXXX.npz` — SAM2 masks (Hanoi-FT auto-selected if present)
- `annotations/side_embeddings/frame_XXXXXX.npz` — 256-D pooled SAM2 embeddings
- `annotations/side_depth_info/frame_XXXXXX.npz` — 3D positions, bboxes, depth-valid flags
- `annotations/side_robot/frame_XXXXXX.npz` — robot bundle (zero-filled in Hanoi v1 for format uniformity)
- `annotations/side_graph.json` — structural edges + `frame_states` deltas derived from `solver_moves` + the gripper-based held-interval detection
- `annotations/dataset_card.json` — schema pointer

Then the usual pipeline:

```python
from gnn_world_model_loader import list_all_frame_graphs
for f, g in list_all_frame_graphs("/path/to/sessions/session_hanoi_<date>_<time>/episode_00"):
    print(f, g)
```

### Step 5 — Retrain the SAM2 Hanoi-FT checkpoint on your own labels

After you've corrected enough frames in the browser UI (step 6), the source-repo training harness pulls `(image, bbox, ground-truth-mask)` triples into a `samples.jsonl` and fine-tunes SAM2's decoder + prompt_encoder (the encoder stays frozen):

```bash
# from source repo:  https://github.com/ChangChrisLiu/gnn-world-model

# 5a. Collect triples.  Prefer collect_hanoi_from_sessions.py for native Hanoi
#     sessions under data/hanoi/ — it accepts explicit --episode, --val-episode,
#     or --all-episodes, and writes a JSONL samples file.
python scripts/sam2_finetune/collect_hanoi_from_sessions.py --all-episodes \
    --out data/sam2_finetune_hanoi/samples.jsonl

# 5b. Fine-tune.  Encoder stays frozen; only decoder + prompt_encoder update.
python scripts/sam2_finetune/train.py \
    --samples data/sam2_finetune_hanoi/samples.jsonl                     \
    --out     tools/hanoi_pipeline/checkpoints/sam2_hanoi_ft.pt          \
    --epochs  25 --lr 1e-4
```

On the next run, both `auto_label.py` and `HanoiGraphInferer()` pick up the new checkpoint automatically from `tools/hanoi_pipeline/checkpoints/sam2_hanoi_ft.pt`. Set `SAM2_FINETUNE_CKPT=<path>` to override, or set it to an empty string to force vanilla SAM2.

### Step 6 — Verify / correct labels in the browser UI (source repo)

The correction UI is a web app (React + FastAPI) that lives in the source repo — it's not bundled here because it's not just a Python module. Clone the source, start the server, and open it:

```bash
# source repo
git clone https://github.com/ChangChrisLiu/gnn-world-model
cd gnn-world-model
bash scripts/run_annotator.sh --hanoi
# → browse to http://localhost:8000
```

The UI loads any labeled Hanoi episode under `data/hanoi/` and lets you fix masks frame-by-frame with bbox / point / brush / eraser / polygon tools. Save writes back to the same `annotations/side_masks/*.npz` files. The format does not change pre- vs post-correction, so downstream loaders are unaffected. The only piece of the UI bundled in the dataset is `tools/hanoi_pipeline/src/annotator/labeling_server.py`, which is the SAM2 backend reused by `infer_graph_from_frame.py`.

### Step 7 — Materialize per-frame graphs to disk (optional, for debugging)

For offline inspection, non-PyTorch consumers, or diff-friendly JSON, the `materialize_per_frame_graphs.py` script writes one `.pt` (and optional `.json`) file per labeled frame:

```bash
python tools/hanoi_pipeline/scripts/materialize_per_frame_graphs.py \
    hanoi/session_hanoi_0415_190808/episode_00 \
    --out     ./per_frame_graphs \
    --variant with_robot_state \
    --also-json
```

Reload:

```python
import torch
data = torch.load("per_frame_graphs/frame_000100.pt", weights_only=False)
print(data)          # Data(x=[4, 270], edge_index=[2, 12], edge_attr=[12, 3], robot_state=[13])
print("is_locked:", data.edge_attr[:, 1].tolist())
```

To iterate in-process without touching disk, `list_all_frame_graphs(episode_dir, variant="with_robot_state")` yields the same `(frame_idx, Data)` pairs directly.

## Shared: common v3 file schemas

### `side_graph.json`

```jsonc
{
  "episode_id": "episode_00",
  "goal_component": "ring_1",            // Desktop: a product id; Hanoi: a ring id
  "view": "side",
  "components": [
    {"id": "ring_1", "type": "ring_1", "color": "#FF0000"}
  ],
  "edges": [
    {"src": "ring_1", "dst": "ring_3", "directed": true}
  ],
  "frame_states": {
    "0":   {"constraints": {"ring_1->ring_3": true},  "visibility": {"ring_1": true}, "held": {}},
    "120": {"constraints": {"ring_1->ring_3": false},                                   "held": {"ring_1": true}}
  },
  "node_positions": {"ring_1": [640, 360]},
  "type_vocab": ["ring_1", "ring_2", "ring_3", "ring_4"],     // Hanoi v1 — no robot
  "embedding_dim": 256,
  "feature_extractor": "sam2.1_hiera_base_plus",

  // Hanoi-only extras:
  "goal_prompt": "Move the red ring to peg B",
  "mission_kind": "single_ring",
  "target_state": {"peg_A": [], "peg_B": ["ring_1"], "peg_C": []}
}
```

### `side_depth_info/frame_XXXXXX.npz` — 7 flat keys per component

| Key | Shape | Dtype | Meaning |
|---|---|---|---|
| `{cid}_point_cloud` | (N, 3) | float32 | 3D points in camera frame (m). (0, 3) if no valid depth |
| `{cid}_pixel_coords` | (N, 2) | int32 | (u, v) of valid depth pixels |
| `{cid}_raw_depths_mm` | (N,) | uint16 | Filtered to [50, 2000] |
| `{cid}_centroid` | (3,) | float32 | Mean of `point_cloud`; `[0,0,0]` if invalid |
| `{cid}_bbox_2d` | (4,) | int32 | `[x1, y1, x2, y2]` from mask |
| `{cid}_area` | (1,) | int32 | Mask pixel count |
| `{cid}_depth_valid` | (1,) | uint8 | 1 if N > 0 else 0 |

### `side_robot/frame_XXXXXX.npz` — always 10 keys

| Key | Shape | Dtype | Meaning |
|---|---|---|---|
| `visible` | (1,) | uint8 | 1 if robot labeled, 0 otherwise |
| `mask` | (H, W) | uint8 | Binary mask |
| `embedding` | (256,) | float32 | SAM2 256-D |
| `point_cloud` | (N, 3) | float32 | 3D points (m) |
| `pixel_coords` | (N, 2) | int32 | (u, v) |
| `raw_depths_mm` | (N,) | uint16 | mm |
| `centroid` | (3,) | float32 | Mean of point cloud |
| `bbox_2d` | (4,) | int32 | From mask |
| `area` | (1,) | int32 | Pixel count |
| `depth_valid` | (1,) | uint8 | 1 if N > 0 else 0 |

## Recording hardware

UR5e + Robotiq 2F-85 gripper; static-mounted Luxonis OAK-D Pro side view with intrinsics `fx = 1033.8`, `fy = 1033.7`, `cx = 632.9`, `cy = 359.9`; recording at 30 Hz, 1280 × 720 RGB and uint16 depth (mm) filtered to `[50, 2000]`.

## License

Released under **CC BY 4.0**. Use, share, and adapt freely with attribution.

## Acknowledgements

- [Segment Anything Model 2 (SAM2)](https://github.com/facebookresearch/sam2) by Meta AI
- [PyTorch Geometric](https://pytorch-geometric.readthedocs.io/)
- [Hugging Face Datasets](https://huggingface.co/docs/datasets)
- Source code: https://github.com/ChangChrisLiu/gnn-world-model