Inverted Path Tracing
I'm not fully educated on how the rendering engines in Blender operate, but I had an idea that could potentially speed up render times significantly for both Eevee and Cycles!
My proposal is to add an option in the render settings titled "Inverted Path Tracing" or something similar, and when enabled it would cause the engine to render light paths from the camera to the light sources, instead of from the light sources to the camera. The idea is that it would cut down on render times by reducing the amount of light that is path traced but useless, because the camera can't see it anyway.
Again, I don't know much about the render engines and I don't have the knowledge to code this myself, but I thought I'd suggest it just in case anyone else is able to make use of it!
2 Comments
Actually, that's usually how path tracers work for the reason you said. Usually it's a ray from a camera finding a light instead of the other way around. The only time this really falls apart is if the lights are small and hard to find, then a bidirectional path tracer is usually what is recommended.
you just described a path tracer. an 'inverted path tracer' is a ray tracer.