Ogaki, ShinjiYuksel, Cem and Membarth, Richard and Zordan, Victor2020-10-302020-10-3020202577-6193https://doi.org/10.1145/3406176https://diglib.eg.org:443/handle/10.1145/3406176Light portals are useful for accelerating the convergence of Monte Carlo path tracing when rendering interiors. However, they are generally limited to flat polygonal shapes. In this paper, we introduce a new concept that allows existing polygon meshes with arbitrary shaders in a scene to be used as generalized light portals. We also present an efficient sampling method that takes into account the pixel values of the environment map and ray guiding two-dimensional textures that are typically opacity or transparency maps. This novel sampling strategy can be combined with other sampling techniques by using multiple importance sampling.Computing methodologiesRenderingRay tracing.illuminationray tracingimage based lightingsampling10.1145/3406176