b3def11f5b
This replaces sequential ray moving followed with scene intersection with single BVH traversal, which gives us all possible intersections. Only implemented for CPU, due to qsort and a bigger memory usage on GPU which we rather avoid. GPU still uses the regular bvh volume intersection code, while CPU now uses the new code. This improves render performance for scenes with: a) Camera inside volume mesh b) SSS mesh intersecting a volume mesh/domain In simple volume files (not much geometry) performance is roughly the same (slightly faster). In files with a lot of geometry, the performance increase is larger. bmps.blend with a volume shader and camera inside the mesh, it renders ~10% faster here. Patch by Sergey and myself. Differential Revision: https://developer.blender.org/D1264