01326nas a2200133   4500000000100000000000100001008004100002100001500043245009700058300001200155490000700167520100300174022001501177       2019                            d1 aLars Grobe00aPhoton mapping in image-based visual comfort assessments with BSDF models of high resolution  a745-7580 v123 aData-driven models replicate the irregular Bidirectional Scattering Distribution Functions (BSDFs) of optically Complex Fenestration Systems in daylight simulation.Radiance employs the tensor tree to store the BSDF at high directional resolution. Its application in backward ray-tracing is however challenging, since the density of stochastic samples must match the model resolution. BSDF proxy and peak extraction address this problem, but are limited to cases when either the fenestration geometry, or the shape and direction of the transmission peak are known. Photon Mapping is proposed to efficiently sample arbitrary BSDFs from the known sun direction. The existing implementation inRadiance is extended to account for light sources and their reflections in the field of view, that are of particular importance for visual comfort assessments. The method achieves a high degree of accordance with ray-tracing, and reduces simulation times by ≈95 % with data-driven models of high resolution.  a1940--1507