Hi,
I am using optix6.5 for rendering. And I am trying to use tex2D to sample the radiance. But I don’t know how can I prevent interpolation in this function. In other words, I only want to use the nearest neighbor to get the radiance. Could anyone helps ? Thank you very much!
I found rtTextureSamplerSetFilteringModes may be useful. But when I call it, always get the complaint that identifier rtTextureSamplerSetFilteringModes is not defined. It should work because I can use rtTextureSampler in the same .cu file.
Please first read this post about the recommended texture usage in OptiX versions before 7:
https://forums.developer.nvidia.com/t/tex3d-optix-7/160756/6
rtTextureSamplerSetFilteringModes is a host function defined in optix_host.h. You cannot call it inside device code. The texture sampler state is immutable there.
Have a look at this code which explains how to setup a texture sampler in the old OptiX API and get a bindless texture ID from it:
https://github.com/nvpro-samples/optix_advanced_samples/blob/master/src/optixIntroduction/optixIntro_07/src/Texture.cpp#L108
That code uses bilinear texture filtering by default.
If you do not want that but nearest texture filtering, you need to change this line:
https://github.com/nvpro-samples/optix_advanced_samples/blob/master/src/optixIntroduction/optixIntro_07/src/Texture.cpp#L167
to m_sampler->setFilteringModes(RT_FILTER_NEAREST, RT_FILTER_NEAREST, mipmapFilter);