A Non-parametric Guide for Radiance Sampling in Global Illumination

Abstract

Global illumination as described by the radiance and potential equations is essentially a sampling problem. This sampling has two elements: 'where' to sample and 'how' to sample. In this paper we propose an alternative method to non-parametric ally simplify the problem of 'where' in the general case. We present a solid angle based uniform sampling scheme with an efficient conservative cull of solid angles not affecting the transfer of radiance between two surfaces. This construction also provides a geometric area bounds within which a surface can receive energy from another along directions contained in the solid angle. The technique can be used to illuminate a scene from a general emitter, including incident light fields. The method has several applications and advantages, with results showing good sampling efficiency and speed.