# AGENTS.md

## Build, Lint, and Test Commands

### Running Tests
```bash
# No explicit test framework found - the project consists mainly of asset configuration files.
```

### Code Style and Conventions

### Python Code Style
- **Formatting**: Use standard PEP 8 style with 4-space indentation
- **Naming Conventions**:
  - `ITEM` dictionary for object metadata (lowercase with underscores)
  - `find_all_items()` and `extract_item_dict()` for function names (snake_case)
  - `usda_path`, `desc_path`, `combined_dict` for variable names (snake_case)
  - `ASSETS_PATH`, `CHROMA_DB_PATH`, `ASSETS_INDEX` for constants (uppercase_with_underscores)
- **Data Structure Style**:
  - Use dictionary definitions with `ITEM = { ... }` format in `item.py` files
  - Keep dictionaries nested with clear keys for objects, shapes, properties
  - Use list format `["name", "position", "quaternion", "scale", "size", "type"]` consistently
  - Include `description` key as empty dict `{}` when no description present
  
### Python Imports
- Import standard library modules at top of file: `os`, `ast`, `hashlib`
- Import pathlib for path operations: `from pathlib import Path`
- Use absolute imports for core functions
- No external library imports in asset files (only dictionaries)

### File Organization
- Asset files: `objects/{category}/{category}_{id}/{id}/item.py`
- Background files: `background/common/{category}/{category}_{id}/item.py`
- Keep `.usda`, `.usd`, `.json`, and texture files in same directory as corresponding item
- Organize by object category with unique identifiers

### Code Organization Principles
```python
# Dictionary-based configuration files
ITEM = {
    "description": {},                # Optional description dict
    "id": "{object_id}",              # Unique identifier
    "shapes": [                       # List of mesh definitions
        {
            "name": "{shape_name}",    # e.g., "bbox", "origin"
            "position": [x, y, z],     # Float position coordinates
            "quaternion": [w, x, y, z],# Quaternion for rotation
            "scale": [x, y, z],       # Scale multipliers
            "size": [x, y, z],        # Physical dimensions
            "type": "{geometry_type}", # e.g., "cube", "sphere"
        }
    ],
    "size": [],                       # Additional size specification
    "url": "path/to/object.usda"      # Path to USD file
}
```

### Error Handling
- Use try-except for file reading operations
- Print informational messages for warnings and errors
- Skip files with errors instead of raising exceptions
- Provide meaningful error messages with file paths

### Type Hints
- Use standard Python types in function signatures
- Path objects with `Path` type hint
- Dictionary types with `dict` hint
- List types with `list` hint
- Number types with `float` or use `number` from typing

### Documentation
- Document complex functions with docstrings
- Use descriptive comments for special cases
- Add error messages inline for critical operations
- Include WARN and ERROR prefixes for important messages

### Asset Tools (Scripts)
The `tools/` directory contains helper scripts for validating and batch-updating asset USD.

**Detailed tool behavior (especially `compile.py`):** see [`tools/AGENTS.md`](tools/AGENTS.md).

- `tools/cleanup.py`: remove generated/cache files inside `assets/` subfolders.
- `tools/compile.py`: compile `Aligned.usda` + `item.py` from `object_parameters.json` / `Aligned.usd` (requires `--dir`; see `tools/AGENTS.md`).
- `tools/review_physics.py`: validate and update `PhysicsMaterial` friction parameters in `.usda` files.

### Agent Docs (synced from tools/)
- `.agent/MODULE.CLEANUP_PY.md`: documentation for `tools/cleanup.py`
- `.agent/MODULE.REVIEW_PY.md`: documentation for `tools/review.py`

### Agent Docs Sync Rules
- Whenever you change `tools/cleanup.py` or `tools/review.py`, update the corresponding module docs under `./.agent/`:
  - `./.agent/MODULE.CLEANUP_PY.md` (for `tools/cleanup.py`)
  - `./.agent/MODULE.REVIEW_PY.md` (for `tools/review.py`)

Recommendation for the agent:
- Re-generate/update the doc content based on `python3 tools/cleanup.py --help` and `python3 tools/review.py --help`.

Examples (run from `assets/` folder):
```bash
python3 tools/review.py --func check --skip-omni6dpose --limit 100
python3 tools/review.py --func check_update --static-friction 0.5 --dynamic-friction 0.3 --limit 100
python3 tools/review.py --func print --limit 50 > physics_material_friction.txt
```