Path Integration for Light Transport in Volumes

Eurographics Symposium on Rendering 2003, June 2003, Leuven, Belgium


Authors


Abstract

Simulating the transport of light in volumes such as clouds or objects with subsurface scattering is computationally expensive. We describe an approximation to such transport using path integration. Path integral formulations of physical processes have been used in physics to solve a wide variety of problems including energy propagation in random media and transfer equation. We harness the idea of light transport expressed as a sum over all possible paths and adapt it for rendering applications. Unlike the more commonly used diffusion approximation, the path integration approach does not rely on the assumption that the material within the volume is dense. Instead, it assumes the phase function of the volume material is strongly forward scattering, an assumption that is often the case in nature. We show that this approach is useful for simulating subsurface scattering and scattering in clouds.
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