Soft Shadow Maps: Efficient Sampling of Light Source Visibility
No Thumbnail Available
Date
2006
Journal Title
Journal ISSN
Volume Title
Publisher
The Eurographics Association and Blackwell Publishing Ltd
Abstract
Shadows, particularly soft shadows, play an important role in the visual perception of a scene by providing visual cues about the shape and position of objects. Several recent algorithms produce soft shadows at interactive rates, but they do not scale well with the number of polygons in the scene or only compute the outer penumbra. In this paper, we present a new algorithm for computing interactive soft shadows on the GPU. Our new approach provides both inner- and outer-penumbra for a modest computational cost, providing interactive frame-rates for models with hundreds of thousands of polygons.Our technique is based on a sampled image of the occluders, as in shadow map techniques. These shadow samples are used in a novel manner, computing their effect on a second projective shadow texture using fragment programs. In essence, the fraction of the light source area hidden by each sample is accumulated at each texel position of this Soft Shadow Map. We include an extensive study of the approximations caused by our algorithm, as well as its computational costs.
Description
@article{10.1111:j.1467-8659.2006.00995.x,
journal = {Computer Graphics Forum},
title = {{Soft Shadow Maps: Efficient Sampling of Light Source Visibility}},
author = {Atty, Lionel and Holzschuch, Nicolas and Lapierre, Marc and Hasenfratz, Jean-Marc and Hansen, Charles and Sillion, Francois X.},
year = {2006},
publisher = {The Eurographics Association and Blackwell Publishing Ltd},
ISSN = {1467-8659},
DOI = {10.1111/j.1467-8659.2006.00995.x}
}