Remaining issues with the gltf loader

[jakobhellermann]

I've tried all the gltf samples models from here and while many already load, here's the list of remaining issues:

TODO:

• Animations
• Coating (ClearCoatTest)
• Environment (EnvironmentTest)
• Morph primitives (MorphPrimitivesTest)
• Multiple UVs (MultiUVTest)
• Material Variants (SheenChair, SheenCloth)
• Transmission (TransmissionTest)
• Two Sided (TwoSidedPlane)
• Texture Transform (TextureTransformMultiTest, TextureTransformTest)
• Loading lights
• KHR_draco_mesh_compression
• glTF-Quantized
• "Embedded" gltf variants (inline data URIs)
• Cameras
• Vertex colors (VertexColorTest)
• data URIs in images
• Missing Vertex_Normal
• Missing UV

Bugs:

• glTF-Sample-Models/2.0/SheenCloth/glTF/SheenCloth.gltf (range end index 263168 out of range for slice of length 262144)
• glTF-Sample-Models/2.0/SimpleSparseAccessor/glTF/SimpleSparseAccessor.gltf (subtract with overflow)
• glTF-Sample-Models/2.0/Box With Spaces/glTF/Box With Spaces.gltf (failed to load path)

[julhe]

I've adressed vertex colors in #1775

[lassade]

@jakobhellermann I was doing a similar work here, can you post the link for your test repo?