GLTFExporter issue: SkinnedMesh looks broken after export (works fine in Three.js)

Questions
,
1

Hi everyone,

I’m currently working on a pipeline where I load custom JSON data (mesh, bones, weights, animation) into Three.js and reconstruct a SkinnedMesh.
In Three.js, the model renders and animates correctly with no issues.

However, when I export the same mesh using GLTFExporter, the resulting .gltf file appears broken into pieces / jagged triangles (especially around the arms and torso).

What I’ve tried

  • Applied LBS weight normalization
  • Used geometry.normalizeNormals()
  • Recomputed normals with geometry.computeVertexNormals()
  • Verified bone hierarchy and skinIndex alignment with skeleton.bones order
    Despite these attempts, the exported GLTF still shows the mesh broken apart.

Questions

  1. Does GLTFExporter require any specific preprocessing of weights or joints before exporting?
  2. Are there any mandatory attributes (like skinIndex type, bone ordering, or normalized weights) that must match for SkinnedMesh export to work properly?
  3. Has anyone experienced similar issues when exporting SkinnedMesh from custom JSON data?

Screenshots

Thanks in advance for any advice or pointers!