Two Methods for Fast Ray-Cast Ambient Occlusion
Ambient occlusion has proven to be a useful tool for producing realistic images, both in offline rendering and interactive applications. In production rendering, ambient occlusion is typically computed by casting a large number of short shadow rays from each visible point, yielding unparalleled qual...
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Published in | Computer graphics forum Vol. 29; no. 4; pp. 1325 - 1333 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Oxford, UK
Blackwell Publishing Ltd
01.06.2010
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Subjects | |
Online Access | Get full text |
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Summary: | Ambient occlusion has proven to be a useful tool for producing realistic images, both in offline rendering and interactive applications. In production rendering, ambient occlusion is typically computed by casting a large number of short shadow rays from each visible point, yielding unparalleled quality but long rendering times. Interactive applications typically use screen‐space approximations which are fast but suffer from systematic errors due to missing information behind the nearest depth layer.
In this paper, we present two efficient methods for calculating ambient occlusion so that the results match those produced by a ray tracer. The first method is targeted for rasterization‐based engines, and it leverages the GPU graphics pipeline for finding occlusion relations between scene triangles and the visible points. The second method is a drop‐in replacement for ambient occlusion computation in offline renderers, allowing the querying of ambient occlusion for any point in the scene. Both methods are based on the principle of simultaneously computing the result of all shadow rays for a single receiver point. |
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Bibliography: | istex:FBF2AEC3DFAFD8D5AECE38B44E93C2D95C9A9DEB ArticleID:CGF1728 ark:/67375/WNG-2KDJK58B-M ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0167-7055 1467-8659 |
DOI: | 10.1111/j.1467-8659.2010.01728.x |