I have a one sided mesh which is not watertight and the normals pointing inwards. Basically a cube with “2D” walls with holes in them. My problem is it renders differently in Cycles depending on if I use the CPU or GPU.
With the CPU I get what I feel is a correct result:
With the GPU this is my result:
Now, I’m pretty sure this is because it is an open mesh with a strong light outside it, but shouldn’t Cycles renders be identical between CPU and GPU?
Closing this mesh will be a huge pain, but I guess I will end up doing it.
I have abandoned GPU renders before because the lighting looked different from the CPU renders, and now I just realized it was because I had several light sources that were “2D” mesh lights stacked behind each other.
Is this expected behavior? Should I just always have a completely closed mesh in any case?