Backface culling of GAS in OptiX7

Gaming and Visualization Technologies Visualization OptiX
1

Simple question. As the intersection program of a GAS isn’t user defined, how can i enable backface culling when tracing a GAS object in OptiX7?

2

For built-in triangle primitives, that is.

You can use the OptixRayFlags for that:
https://raytracing-docs.nvidia.com/optix7/api/html/group__optix__types.html#ga50e4054620bfddb9b3e282d1a53e211b

Also have a look at the OptixInstanceFlags which can control the triangle facing.
https://raytracing-docs.nvidia.com/optix7/api/html/group__optix__types.html#gadefef6077edef8bb8f4008d27d784745
You would need to have a dummy IAS with identity transform over the GAS to make use of those.

Please check the OptiX 7.0.0 online programming guide here https://raytracing-docs.nvidia.com/optix7/guide/index.html and put in “cull” into the search field in the top right.
I’m normally using “Find In Files” on the OptiX 7.0.0 SDK headers and sources first.