The glTF loading routines inside the OptiX SDK aren’t supporting all allowed glTF data formats.
For example uchar vertex indices, and in your case most likely color attributes which aren’t float3, etc.
There have been some discussions about these limitations before:
https://forums.developer.nvidia.com/t/optixwhitted-how-to-insert-scene-from-opennurbs-on-mesh/278134/5
https://forums.developer.nvidia.com/t/misaligned-address-exception-when-rendering-some-gltf2-models/107169/2
You should be able to determine what it was by setting breakpoints on the code line throwing that gltf accessor component type not supported error message inside the template function bufferViewFromGLTF
In case you want to look at glTF 2.0 files with OptiX, I wrote this GLTF_renderer example which handles these things and a lot more:
https://forums.developer.nvidia.com/t/optix-advanced-samples-on-github/48410/16
https://forums.developer.nvidia.com/t/load-scene-with-optix/291957/2
It’s also not supporting all glTF 2.0 features, yet, like any other primitive type than triangles, animation, skinning morphing, unicode filenames.
I’m currently adding animation support.
Also VTK should be able to support OptiX ray tracing via an Anari plugin.
Look for VTK and VisRTX here: https://www.khronos.org/anari/