We are seeing strange behavior when dealing with Draco compressed GLTF files that use multiple UV sets. When compressing with Draco, any UV sets beyond the first two are lost. I have a very simple example using a cube mentioned here. This behavior can be reproduced using Modo, Blender, or GLTF Pipeline to do the compression.
Just to confirm – it looks like the issue was a (just fixed) issue in Babylon.js? Both files at the attachment do appear to have all UV sets intact.
Yes, this was a bug in the Babylon.js glTF loader.
Yes, thank you Don!
This issue appears to be unrelated to Draco.