docs/storage_spec.md

# Asset Storage Specification

## Canonical path

```text
assets/<source>/<asset_type>/<category>/<asset_id>/
```

For large upstream trees that rely on many relative references, a collection-level import may be stored at:

```text
assets/<source>/<upstream_root>/
```

In that case, keep the upstream directory layout intact and index the collection with a root `metadata.yaml`.

## Required per-asset files

- Source asset files, preserving upstream structure where practical.
- `metadata.yaml`.

## Global index

All assets must be indexed in:

```text
manifest/assets.jsonl
```

Use one JSON object per line.

## MJCF assets

For MuJoCo/MJCF assets:

- `model.xml` is the preferred entry file.
- Meshes and textures should remain relative to `model.xml`.
- Common mesh formats: `.obj`, `.stl`, `.dae`.
- Common texture formats: `.png`, `.jpg`, `.jpeg`.

Example:

```text
assets/robocasa/fixtures/dishwashers/Dishwasher031/
├── metadata.yaml
├── model.xml
└── visuals/
    ├── Body001.obj
    └── T_BC001.png
```