Irradiance Gradients

Irradiance Gradients

TitleIrradiance Gradients
Publication TypeConference Paper
Year of Publication1992
AuthorsGregory J Ward, Paul S Heckbert
Conference NameEurographics Rendering Workshop
Date Published05/1992
Conference LocationBristol, England
Call NumberLBL-32205
Abstract

A new method for improving the accuracy of a diffuse interreflection calculation is introduced in a ray tracing context. The information from a hemispherical sampling of the luminous environment is interpreted in a new way to predict the change in irradiance as a function of position and surface orientation. The additional computation involved is modest and the benefit is substantial. An improved interpolation of irradiance resulting from the gradient calculation produces smoother, more accurate renderings. This result is achieved through better utilization of ray samples rather than additional samples or alternate sampling strategies. Thus, the technique is applicable to a variety of global illumination algorithms that use hemicubes or Monte Carlo sampling techniques.

LBNL Report Number

LBL-32205