# Heart models v4/v5 — sources and attribution

This asset adapts the retained `human-heart-v3.glb`, derived from **Z-Anatomy — The libre 3D atlas of anatomy**, CC BY-SA 4.0, and adds three meshes from **BodyParts3D 4.0**.

- Z-Anatomy: https://github.com/Z-Anatomy/Models-of-human-anatomy
- Z-Anatomy attribution: Gauthier Kervyn and Marcin Zielinski; original BodyParts3D model by Kousaku Okubo / The Database Center for Life Science.
- BodyParts3D, © The Database Center for Life Science licensed under CC Attribution 4.0 International. Current source terms: https://dbarchive.biosciencedbc.jp/en/bodyparts3d/lic.html (checked 2026-09-09).
- Inherited Z-Anatomy attribution for its historical BodyParts3D source: CC BY-SA 2.1 Japan.

The adapted **v4 and v5 models** is distributed under CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/ . This asset notice does not relicense unrelated platform code.

Changes: added anterior mitral leaflet (FJ2420), anterior tricuspid leaflet (FJ2421), and left anterolateral papillary muscle (FJ2418); registered the source coordinates against six inherited cardiac structures; recomputed normals for additions; applied Meshopt compression and quantization without triangle decimation. V5 reconstructs the same additions from v3 and the original OBJ inputs without the quantization or Meshopt step; inherited float attributes, indices and transforms are preserved exactly. Colours and visibility are controlled by the learning resource.

The model is an educational approximation. Chordae remain combined with leaflet meshes; junctions and vascular branching are simplified. Independent anatomical review is still pending. See `docs/anatomy-assets/human-heart/asset-v5.json` (v4 history: `asset-v4.json`) and `registration-v4.json` in the source repository for provenance and numerical verification.