I read an old post that texture arrays are not supported in optix, and we should use bindless texturing. Is that still true in the latest version? What about 3D volume textures?
All supported texture types in CUDA are available via OptiX bindless textures and the OptiX rtTex*(id, …) intrinsics you’ll find in the optix_device.h header.
See my answer in your other question about null initializations for links with more details.