I’m building an accel containing nothing but curves, and it renders fine. However, if I create a compacted accel from that working accel and attempt to use that, Optix is very unhappy, reporting OPTIX_EXCEPTION_CODE_BUILTIN_IS_MISMATCH in validation mode and rendering black squares where the curves should be. If I turn on exceptions, I see the error “error: mismatch between builtin IS shader and build input”.
I’m using the same compaction code for other BVHs not containing curves and they work properly.
I noticed that the SDK optixCurves example does not compact its BVH, suggesting this is a known issue or limitation.
This same error happens with 7.1 and 7.2.
I can’t decide whether this is a bug in Optix or I have an obscure problem in my own code.