Random Walk subsurface scattering did look different with OptiX because transmittance is calculated based on the hit distance, but the OptiX implementation of `scene_intersect_local` would return the distance in world space, while the Cycles BVH version returns it in object space. This fixes the problem by simply skipping the object->world transforms in all the places using the result of `scene_intersect_local` with OptiX. Reviewed By: brecht Differential Revision: https://developer.blender.org/D7232