COLLADA and GLTF 2.0 Batch IDs

Ladies and gents,

We’ve long been using B3DM files in our Cesium-based application, generated via COLLADA2GLTF and then our own tools to go from COLLADA (.dae) -> GLTF (.glb) -> B3DM ( -> CMPT). Unfortunately, we don’t actually have per-vertex batch IDs. We need two things:

  1. Per-vertex batch IDs stored in the COLLADA files (ie, support in the OpenCOLLADA library for reading, storing, and writing batch IDs.

  2. Ability for COLLADA2GLTF to write per-vertex batch IDs.

We haven’t been able to find any branches/forks of the relevant repos (COLLADA2GLTF and OpenCOLLADA), either from Khronos or from you guys, that implement those, but we don’t want to waste our time on the implementation if it’s already done. Are you aware of where, if anywhere, those features are currently implemented? Thanks in advance!


Christopher Mitchell

I’m a bit out of touch with the latest COLLADA2GLTF converter, but COLLADA supports custom vertex attributes so I think it’s just a matter of getting COLLADA2GLTF to write them out. Maybe open an issue in COLLADA2GLTF first asking about custom attribute support, but as far as I know there isn’t any work being done on this.