[ginko]

The author mentions using frustum culling for performance. Won't this lead to lighting artifacts with indirect illumination when path tracing? Even when an object is behind the camera it could still affect the lighting of what's in front of it.

[kipi]

Author here, I intersect the view frustum with the light's sphere of influence (and also take into account PVS info) so it still includes lights that are reachable by one bounce. Technically this means I might omit two bounce reflections but in practice this doesn't appear to be a problem.

[Jasper_]

Since it's coarse as the BSP, you won't lose objects behind you. The BSP data structure doesn't take into account the camera's looking direction, just the camera's position. Thus, it includes every object visible from all possible looking directions visible at a given point, so it will always include objects behind you.