@becomethewaifu @0xabad1dea I had a 3d graphics class about 20 years ago where the lecturer claimed that the bottleneck in ray tracing renderers is usually cache misses for reflected rays. I think he used the phrase "primary rays cache, secondary rays thrash". The primary rays (the ones that go out of the camera into the scene) mostly get to take advantage of CPU cache because they point in very nearly the same direction as the other primary rays adjacent to them. But then secondary rays that bounce from the surfaces in the scene thrash CPU cache because they fly off in all directions, from different starting points. I liked that lecturer. Dutch gentleman, I think, and a very good teacher. I remember him once explaining something about how things work when there's only one light in a scene, and he started by saying "If I had enough bricks to smash all but one of the lights in this room..." :D