skinned-glb

A skinned, morphing mesh out as a GLB. writeSkinnedGlb writes one skeleton, any number of meshes skinned to it (four influences a vertex), each with morph targets named in extras.targetNames, and plain glTF metallic-roughness materials with their images embedded. Pure: no Babylon, no DOM, synchronous, bytes out. It is writeGarmentGlb's sibling for rigged bodies, which that writer does not do (no skin, no morphs).

Part of the character core: import it as tosijs-3d/skinned-glb. Written for Dramatis's character exporter (GLB and VRM), and checked against the Khronos validator and Babylon's own loader.

import { writeSkinnedGlb } from 'tosijs-3d/skinned-glb'
const bytes = writeSkinnedGlb({ asset, joints, skinName, skeletonRoot, inverseBindMatrices, meshes, materials, images })

What it guarantees, so the Khronos validator is clean:

• joints are nodes 0..n-1, in the order given, each parent before its children; every mesh is its own top-level node with no transform;
• POSITION accessors (and every morph target's) carry min and max;
• normals are unit length (a zero normal becomes +Y); weights are renormalised in float32 so each vertex's sum is 1, and a joint never appears twice in one vertex's non-zero slots;
• indices are UNSIGNED_SHORT below 65,535 vertices, UNSIGNED_INT above;
• morph targets are sparse accessors over the vertices they move (a target that moves nothing is the caller's to leave out; one here throws);
• KHR_materials_sheen is listed in extensionsUsed only when a material has sheen; nothing is ever required.