Two Stage Importance Sampling for Direct Lighting

Cline, David; Egbert, Parris K.; Talbot, Justin F.; Cardon, David L.

Two Stage Importance Sampling for Direct Lighting

Files

103-113.pdf (513.81 KB)

Date

2006

Authors

Cline, David
Egbert, Parris K.
Talbot, Justin F.
Cardon, David L.

Publisher

The Eurographics Association

Abstract

We describe an importance sampling method to generate samples based on the product of a BRDF and an environment map or large light source. The method works by creating a hierarchical partition of the light source based on the BRDF function for each primary (eye) ray in a ray tracer. This partition, along with a summed area table of the light source, form an approximation to the product function that is suitable for importance sampling. The partition is used to guide a sample warping algorithm to transform a uniform distribution of points so that they approximate the product distribution. The technique is unbiased, requires little precomputation, and we demonstrate that it works well for a variety of BRDF types. Further, we present an adaptive method which allocates varying numbers of samples to different image pixels to reduce shadow artifacts.

        @inproceedings{:10.2312/EGWR/EGSR06/103-113
,
booktitle = {Symposium on Rendering
},
editor = {Tomas Akenine-Moeller and Wolfgang Heidrich
},
title = {{Two Stage Importance Sampling for Direct Lighting
}},
author = {Cline, David and 
Egbert, Parris K. and 
Talbot, Justin F. and 
Cardon, David L.
},
year = {2006
},
publisher = {The Eurographics Association
},
ISSN = {1727-3463
},
ISBN = {3-905673-35-5
},
DOI = {/10.2312/EGWR/EGSR06/103-113
}
}