When converting a single mesh with multiple material IDs assigned per triangle, the exporter chooses one of the materials and assigns it to the whole mesh. This is an issue for optimization of draw calls where an artist may combine multiple manifold meshes into one but retain the individual materials of the original multiple mesh model.
When converting a single mesh with multiple material IDs assigned per triangle, the exporter chooses one of the materials and assigns it to the whole mesh. This is an issue for optimization of draw calls where an artist may combine multiple manifold meshes into one but retain the individual materials of the original multiple mesh model.
This is the single mesh as set up in Unity:
This is the glb that was exported: