I have a shader that renders a mesh using custom per-vertex data. Currently, I load in the mesh and the data separately, and then set the vertices data using the setVerticesData() method. This works, but it would be far more convenient to store the per-vertex data directly in the GLTF2 file. I think it should be possible to store custom per-vertex data on a GLTF2 file according to this discussion. Would such a file be parsed correctly by Babylon? And if so, do you know of a good way to generate a GLTF2 with custom per-vertex data using pygltflib (which is what I am currently using to generate the GLTF2)?
As far as I know KRONOS is pushing towards a rule: don’t include anything non-visible in the file.
So if the data are not related to render the object, it will be stripped when exported.
However it’s quite common to use vertex colors for storing data per vertex.
You can store custom data as extras according to the GLTF2 specs but it doesn’t count as per vertex data.