Support for GLTF Custom Vertex Attributes

{
    "meshes": [
        {
            "primitives": [
                {
                    "attributes": {
                        "NORMAL": 23,
                        "POSITION": 22,
                        "TANGENT": 24,
                        "TEXCOORD_0": 25,
                        "_BATCHID ": 26
                    },
                    "indices": 21,
                    "material": 3,
                    "mode": 4
                }
            ]
        }
    ]
}

See the above snippet. I’d like to be able to insert custom vertex data, more specifically _BATCHID for Cesium 3d tiles.

There’s no way of doing this currently, and I’m working around it by using the official .net gltf 2 library which is very low level.

Could the gltf importer and exporter support custom vertex element types?
_BATCHID in this case is an integer, but it would be nice to have flexibility to support the vectors of various lengths.

@bortos

An investigation ticket as THREEDNET-1119 has been logged in our issue management system to further review your requirements. We will look into its details and let you know as soon as the ticket is resolved. Please give us some time.