# PhysDojo: Dense Physics Annotations for DreamDojo

Per-frame per-object physics labels extracted from DreamDojo robot manipulation episodes
using off-the-shelf foundation models (no VLM).

## Pipeline
- **RAFT** optical flow → per-pixel velocities
- **Depth Anything V2** → metric depth → 3D positions
- **DINOv2** → material features

## Format
Each episode has `physics_dense.npz` containing:
- `positions`: (T, N_obj, 2) — normalized [0,1] centroids
- `velocities`: (T, N_obj, 2) — pixels/sec
- `accelerations`: (T, N_obj, 2) — pixels/sec²
- `depths`: (T, N_obj) — relative depth
- `contacts`: (T, N_obj, N_obj) — binary contact matrix
- `masks`: (T, N_obj) — object presence mask
- `optical_flow`: (T-1, 2, H, W) — dense flow fields
- `material_features`: (T, feature_dim) — DINOv2 CLS features

## Stats
- Episodes annotated: 11643
- Source: miemiebabu/efference-wm-16k