My light mapper can generate soft shadows just fine - for each texel I cast a ray to the light, offset by some distribution of the 'area' of the light on disc. The problem is that I am casting many rays and that slows down production. I note that even for texels completely in shadow, I still cast 128 rays towards the light, but none of them hit it. This seems like a waste of effort. I imagine I could try to intersect a cone with the scene to reject cases when the texel is so deeply in shadow that multiple rays would be ineffective, but I currently only have a ray-tracer at my disposal, so before I go on I wanted to know if anyone has any good ideas. How can I accelerate the calculation of soft-shadows on the CPU?
Acceleration techniques for CPU soft-shadow calculation in light mapper
raytracing;lighting;sampling