importance sampling

[kkevlar]

Hmmm I wonder what this means

[JustinPrivitera]

this is an optimization that should make our ray tracer run much faster

to boil it down, we could/will implement a kind of importance sampling where, before casting any rays, we can prove for a set of pixels that any rays cast from those pixels will hit no scene objects. With that information, we can skip ray creation for those pixels, and thus skip a lot of ray collision detection that we would normally need to do, which is the most computationally expensive part of ray tracing.