A Hybrid GPU Rendering Pipeline for Alias-Free Hard Shadows

Hertel, Stefan; Hormann, Kai; Westermann, Rüdiger

A Hybrid GPU Rendering Pipeline for Alias-Free Hard Shadows

Files

059-066.pdf (295.98 KB)

Date

2009

Authors

Hertel, Stefan
Hormann, Kai
Westermann, Rüdiger

Publisher

The Eurographics Association

Abstract

We present a new GPU pipeline for rendering per-pixel exact shadows that are cast by point lights and parallel lights. Our approach is hybrid in that it uses kD-tree accelerated ray-tracing to determine shadow-ray intersections, and rasterization to effectively reduce both the number of shadow rays to be traversed and the number of sub-spaces to be considered along each of these rays. To achieve this we introduce conservative shadow maps, which store a conservative estimate of the first intersection with the scene for each possible shadow ray. A novel approach to build such a map is presented, which uses rasterization to compute for every shadow-map pixel the triangles intersecting this pixel. By exploiting the rasterization capacities of recent GPUs in combination with accurate ray-triangle intersection tests, we are able to efficiently compute alias-free shadows in high-resolution and spatially extended scenes where classical shadow mapping techniques have severe difficulties.

        @inproceedings{10.2312:ega.20091009
,
booktitle = {Eurographics 2009 - Areas Papers
},
editor = {D. Ebert and J. Krüger
},
title = {{A Hybrid GPU Rendering Pipeline for Alias-Free Hard Shadows
}},
author = {Hertel, Stefan and 
Hormann, Kai and 
Westermann, Rüdiger
},
year = {2009
},
publisher = {The Eurographics Association
},
ISBN = {},
DOI = {10.2312/ega.20091009
}
}