# gate_scenes_export

Self-contained bundle of two sagesplat scenes (left/right) plus the object
extractions in their shared (joint) mocap frame.

## Layout

```
gate_scenes_export/
├── README.md
├── MANIFEST.txt
├── left_scene/
│   ├── mocap_processed/                         # data dir (referenced by config.yml as "./mocap_processed")
│   │   ├── images/                              # 242 corrected RGB frames
│   │   ├── transforms.json                      # mocap-frame camera poses
│   │   └── sparse_pc.ply                        # initial point cloud (mocap frame)
│   └── mocap_outputs/sagesplat_mocap/sagesplat/2026-05-11_153901/
│       ├── config.yml                           # trainer config (data path is relative)
│       ├── dataparser_transforms.json           # mocap → nerfstudio internal frame
│       └── nerfstudio_models/step-000029999.ckpt
├── right_scene/                                  # mirror layout
│   └── ...                                      #   training run timestamp 2026-05-11_144353
└── objects_final/
    ├── README.md                                # detailed transform usage
    ├── left_gate.ply,  right_gate.ply           # all PLYs in JOINT mocap frame
    ├── left_table.ply, right_table.ply
    ├── joint_mocap_to_nerf.json                 # the transforms
    ├── objects_summary.json                     # per-object AABBs, plane, polygon
    └── right_to_left_icp.json                   # ICP that built joint mocap
```

`config.yml` stores the data path as the **relative** string `mocap_processed`,
so ns-viewer/ns-eval/ns-render must be launched with the scene directory as
`cwd`. Everything else (checkpoint, dataparser transform) is referenced as
a path relative to the run timestamp directory.

## Environment

This bundle was produced with the conda env `sagesplat` at
`/home/javier/miniconda3/envs/sagesplat`. To reproduce on another host:

- python 3.10
- pytorch 2.1.2 + cu118
- nerfstudio 1.1.5
- gsplat 1.4.0
- tinycudann (built against the same CUDA toolkit)
- sagesplat (editable install from
  [Splat-MOVER](https://github.com/StanfordMSL/Splat-MOVER))
- runtime env knobs we use on this machine:
  - `PYTHONNOUSERSITE=1` (so `~/.local/lib/python3.10/site-packages` doesn't
    shadow the conda env)
  - `QT_QPA_PLATFORM=offscreen` (only relevant when running headless)
  - `CUDA_HOME` set to a conda env that ships a full CUDA toolkit, with
    `LIBRARY_PATH` extended with that env's stubs+system libcuda

## Launching `ns-viewer` for a scene

```bash
# left
cd gate_scenes_export/left_scene
ns-viewer --load-config mocap_outputs/sagesplat_mocap/sagesplat/2026-05-11_153901/config.yml

# right
cd gate_scenes_export/right_scene
ns-viewer --load-config mocap_outputs/sagesplat_mocap/sagesplat/2026-05-11_144353/config.yml
```

Viser will bind to `http://0.0.0.0:7007`. `ns-eval` / `ns-render` take the
same `--load-config` argument.

## Using the object point clouds

See `objects_final/README.md` for the full transform chain and copy-pastable
Python snippets. Short version:

- All PLYs in `objects_final/` are in the **joint mocap frame**:
  z-up, origin at the ArUco tag, +x along the tag's printed +y direction.
- The right scene's PLYs have an ICP correction baked in so they
  align with the left scene's mocap (the joint reference).
- `objects_final/joint_mocap_to_nerf.json` carries the per-scene 4×4
  matrices needed to push points from joint mocap into either splat's
  nerfstudio-internal frame (for use with `cv.aruco`-style PnP, or to
  query the splat for renders at a specific mocap pose).

## Frame conventions, quick reference

| frame | origin | up | notes |
|---|---|---|---|
| joint mocap | ArUco tag center | +z | reference; equals left scene's mocap |
| left mocap | tag center | +z | identical to joint mocap |
| right mocap | tag center | +z | offset by ICP correction (≈70 mm xyz, -0.5° yaw) |
| left nerf-internal | shifted | +z (auto-oriented) | nerfstudio dataparser applied |
| right nerf-internal | shifted | +z (auto-oriented) | nerfstudio dataparser applied |

## Total size: ~12 GB

Per-component:
- `left_scene/`  : 76 MB data + 4.9 GB checkpoint = ~5.0 GB
- `right_scene/` : 71 MB data + 6.3 GB checkpoint = ~6.4 GB
- `objects_final/` : 11 MB

`MANIFEST.txt` carries a build-time snapshot of the same.