Vertex colors don't load

Description

I’ve been working on #16 and run into an issue where vertex colors don’t load either for meshes or point clouds.

The vertex attribute descriptors appear correct: VertexAttribute=Color, VertexAttributeFormat=UInt8, numComponents=4, elementSize=4

Attempting to access unityMesh.colors results in:

Unsupported conversion of vertex data (format 6 to 0, dimensions 4 to 4)
UnityEngine.Mesh:get_colors ()

If the resulting array (from unityMesh.colors) is read the results are all rgba(0,0,0,0), hence the black.

This applies to both point clouds (in my WIP implementation) and meshes (in main)

There’s minimal discussion of MeshData online, but I did see this which suggests it could be a Unity issue.

Colors do load correctly in GLTFast when models are not draco compressed.

Environment

Unity 2020.3.15f2 DracoUnity main https://github.com/atteneder/DracoUnity/commit/9f5161b5eec0c99425ec0e207ec1e7df5eea5cd1

Expected Behaviour

In three.js: Point Cloud (vertex colors) on left, Mesh (vertex colors) in center, Mesh (no colors) on right.

Actual Behaviour

In GLTFast/DracoUnity:

[camnewnham]

Thanks @atteneder, good find! Confirming that this works for me.

[benvvalk]

It works!

I just confirmed that the vertex colors load correctly in Piglet using the HEAD DracoUnity version. I tested with Unity 2020.3.9f1, using the bunny model above and also with the example model that my customer shared privately.