Radiance Photon Mapping

Daylight redirecting components are characterized by complex transmissive and reflective behavior that is difficult to predict accurately, due mostly to their highly directional scattering properties and the caustics this produces.

Photon mapping is a forward raytracing technique that supplements Radiance’s standard backward ray-tracer, resulting in bidirectional light transport. Photon mapping is particularly effective at evaluating the daylighting and visual comfort performance of highly specular daylight redirecting systems.