Hachisuka, ToshiyaGeorgiev, IliyanJarosz, WojciechKřivánek, JaroslavNowrouzezahrai, DerekMatthias Zwicker and Pedro Sander2017-06-192017-06-192017978-3-03868-045-11727-3463https://doi.org/10.2312/sre.20171195https://diglib.eg.org:443/handle/10.2312/sre20171195We propose an extension of the path integral formulation amenable to the expression of volumetric light transport with photon beam estimates. Our main contribution is a generalization of Hachisuka et al.'s extended path space formulation [HPJ12] to light transport in participating media. Our formulation supports various point- and beam-based volumetric density estimators, unifying them with path integration in the spirit of the work by Kˇrivánek et al. [KGH 14]. One unique and useful property of our formulation is that it recasts beam-based density estimation as Monte Carlo path vertex sampling in a higher-dimensional space, rather than beam merging in a lower-dimensional space, which enables a practical algorithm for beam estimators with 3D-blur kernels. We thus establish a complementary theoretical foundation for the development of rendering algorithms using points, beams, and paths in participating media.10.2312/sre.2017119565-70