# Structure Mapping Record

Whenever an upstream asset source is reorganized during import, record the mapping between:

- original upstream directory layout
- current on-disk layout in this repository
- reason for the transformation
- whether internal relative references were preserved

## Required fields

For each source, record:

- `upstream_root`
- `original_layout`
- `current_layout`
- `mapping_notes`
- `reference_preservation`

## Why this matters

Without explicit structure mapping, a repository can no longer answer:

- which files came from which upstream directory
- whether a path change was semantic or only organizational
- whether relative XML/mesh references were preserved
- how to re-import a source after upstream updates

## Rule

If you change a source’s on-disk structure, update:

- `docs/source_notes/<source>.md`
- the source’s `metadata.yaml`
- any manifest row that stores `path`

## Current storage layers

```text
assets/<source>/raw/...
assets/<source>/derived/...
```

- `raw/`: source-preserved imported files. Do not overwrite these during processing.
- `derived/`: generated or transformed outputs such as convex decomposition results, collision meshes, cleaned meshes, and format conversions.

Derived outputs must point back to their raw inputs through `metadata.yaml` and `source_refs.yaml`.