The model animated its skeleton but rendered a permanent T-pose: the mesh
wasn't skin-bound. Root cause was in autorig's binding, introduced while
chasing an earlier "skins:0" export:
- The earlier "skins:0" was actually caused by bone-heat weighting failing
(0 weighted verts → empty skin gets dropped), NOT by the Armature modifier.
- The "fix" then stripped the Armature modifier and used parent_type=ARMATURE.
That makes the glTF exporter emit a skin OBJECT but with no node.skin
reference and no per-vertex JOINTS/WEIGHTS — an orphan skin. The mesh then
renders its bind pose (T-pose) forever while the skeleton animates unseen.
Fix: keep the standard ARMATURE_AUTO result (Armature modifier + vertex
groups). With the nearest-bone fallback ensuring real weights, the exporter
now writes a COMPLETE skin (verified: meshnode.skin=0, JOINTS/WEIGHTS present).
Also:
- skinned_player_model: _ensure_meshes_bound() re-binds any skinned mesh whose
skeleton NodePath doesn't resolve at load — graceful degradation instead of
a silent T-pose for imperfect GLBs.
- smoke test now asserts the spawned player's mesh is bound to its skeleton,
so this class of bug fails the test instead of shipping. 30/30 pass.
- regenerated miku_test.glb with the corrected pipeline.
Co-Authored-By: Claude Fable 5 <[email protected]>
