# Z-Anatomy musculoskeletal and limb peripheral nerve subset

Z-Anatomy — The libre 3D atlas of anatomy — CC BY-SA 4.0.

- Gauthier Kervyn: design, 3D, anatomy.
- Marcin Zielinski: Blender add-on.
- Original model: BodyParts3D — The Database Center for Life Science, Kousaku Okubo. Upstream credits specify CC BY-SA 2.1 Japan; the current BodyParts3D archive separately uses CC BY 4.0. The Z-Anatomy adaptations here remain CC BY-SA 4.0.
- Source: https://github.com/Z-Anatomy/Models-of-human-anatomy
- Pinned revision: `3e343336567a817ec6bdd77132ecf9672570bde7`
- Source archive: `Z-Anatomy.zip`, SHA-256 `e029688545627bd0214b269e1063143abb580aad72b2c2445d6d8a9a0d9da736`
- Original license and credits: [UPSTREAM-LICENSE.txt](./UPSTREAM-LICENSE.txt)
- License: https://creativecommons.org/licenses/by-sa/4.0/
- Full license: [LICENSE.txt](./LICENSE.txt)

## Scope and changes

The extracted geometry contains the surface objects in the skeletal and muscular collections, and only peripheral nerve objects also assigned to a limb collection. Objects without surface triangles (annotation points/landmarks) are omitted. Muscle-associated fascia, bursae and tendon sheaths are displayed as connective tissue. Object identities and source collection membership are recorded in [provenance.json](./provenance.json).

The models retain their original spatial relationships. Positions convert from meter/Z-up `(x,y,z)` to meter/Y-up `(x,z,-y)`; Blender curves are evaluated into meshes with their original bevels. Non-nerve geometry is simplified with a maximum relative error of 0.2% per part. Nerve triangles are not simplified. Normals are quantized to signed 16-bit, buffers are packed and gzip-compressed. Colors are supplied by the viewer. English display names, Japanese label overlays and bilateral selection groups were added; new ZA identifiers do not claim FMA identity.

These adapted model assets, manifests and label overlays are offered under CC BY-SA 4.0. Japanese labels additionally draw on the existing BodyParts3D (CC BY 4.0) name overlay and curated standard terms. No upstream Wikipedia definitions or embedded application scripts are distributed.

The upstream license lists additional works with separate conditions (inner ear: CC BY-NC-SA; kidney: CC BY-NC; University of Washington white matter without an explicit license in that notice). The inner-ear model, kidneys, CNS/white matter and cranial nerves are outside the selected scope. This positive subset follows the upstream CC BY-SA 4.0 declaration; upstream does not provide an independently verified per-object authorship warranty. Do not treat this as permission to redistribute all upstream assets under one license.

The atlas is an educational reference, does not cover all anatomical variation or nerve branches, and has not undergone expert anatomical review in this application. No warranty is provided; see the license terms.

## Surface orientation correction (2026-09-07)

Corrected triangle winding on mirrored surfaces to agree with outward vertex normals. Vertex positions, normals, triangle membership and anatomical placement are unchanged. Geometry URLs now include a content hash to prevent stale cached buffers.