| # OB3D Re-encoding — exact procedure |
|
|
| ## Upstream layout (input) |
|
|
| OB3D ships dense cubemap RGB-D-pose trajectories. Place the upstream data under `data/ob3d/` matching this layout: |
|
|
| ``` |
| data/ob3d/ |
| ├── <scene_name>-Egocentric/ |
| │ ├── cubemap/ |
| │ │ ├── px/{frame_NNNN.png, frame_NNNN_depth.npy} # +X face |
| │ │ ├── nx/ # -X face |
| │ │ ├── py/, ny/, pz/, nz/ # remaining faces |
| │ ├── pose/ |
| │ │ └── pose_NNNN.json # source pose convention |
| │ └── … |
| └── <scene_name>-Non-Egocentric/ |
| └── (same structure) |
| ``` |
|
|
| The exact upstream filenames depend on which OB3D distribution you use; the `pipeline.py` reads the layout from `config.yaml` so adjust `input_layout` there if needed. |
|
|
| ## Output schema (CM-EVS unified) |
|
|
| ``` |
| outputs/ob3d/<scene_name>-<viewpoint>/ |
| ├── meta.json # coordinate convention, first-frame center |
| ├── panorama_0000.png # ERP RGB, 1600×800 |
| ├── panorama_0000_depth.npy # ERP range depth (m), float32 |
| ├── pose_0000.json # { qwc: [w,x,y,z], position: [x,y,z], camera_type: "cubemap_reencoded" } |
| ├── panorama_0001.png |
| ├── panorama_0001_depth.npy |
| ├── pose_0001.json |
| └── … |
| ``` |
|
|
| ## Run |
|
|
| ```bash |
| cd ../../code |
| python scripts/reencode_outdoor.py \ |
| --source ob3d \ |
| --config ../adapters/ob3d/config.yaml |
| ``` |
|
|
| The script: |
|
|
| 1. Loads `config.yaml` → resolves cubemap face size, axis conversion, ERP target resolution. |
| 2. For each scene/viewpoint listed in `metadata/source_manifest.json`: |
| - Reads the 6 cubemap faces per frame, concatenates into ERP via standard cubemap → equirectangular projection. |
| - Re-projects depth: cubemap perspective `z` → ERP **range** depth (radial). |
| - Reads source pose, converts axis convention to CM-EVS world frame, expresses as `q_wc` + position. |
| - Writes the triple `panorama_NNNN.{png, _depth.npy}` and `pose_NNNN.json`. |
| 3. Emits per-scene `meta.json` re-stating the coordinate convention. |
|
|
| ## Verifying against paper |
|
|
| After running, compare with paper §4.3 Table 4: |
|
|
| - 12 scenes × 2 viewpoints = 24 instances ✓ |
| - 200 frames each = 2,400 frames ✓ |
| - Resolution 1600×800 ✓ |
| - Median depth 3.88 m ✓ (sanity-check via your favorite stats script) |
|
|
| ## Caveats |
|
|
| - **No curator selection**. Paper §4.2 Table 3 row "Outdoor / OB3D" notes that all v1.0 outdoor frames are full re-encoded source trajectories, not curator-selected subsets. Therefore no `metadata/per_step_log.jsonl` is emitted. |
| - **License**: frames produced by this adapter remain under upstream OB3D license. Do not redistribute without checking upstream terms. |
|
|
