shadow silhouette maps pradeep sen mike cammarano pat hanrahan stanford university

Shadow Silhouette MapsShadow Silhouette MapsPradeep Sen Mike Cammarano Pat HanrahanPradeep Sen Mike Cammarano Pat Hanrahan

Stanford UniversityStanford University

Speaker: AlvinSpeaker: Alvin

Date: 8/24/2003Date: 8/24/2003

SIGGRAPH 2003SIGGRAPH 2003

Alivn/GAME LAB/CSIAlivn/GAME LAB/CSIE/NDHUE/NDHU

Shadow Silhouette MapsShadow Silhouette Maps 22

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IntroductionIntroduction AlgorithmAlgorithm ResultResult ArtifactsArtifacts Conclusion & Future WorkConclusion & Future Work



IntroductionIntroduction

SilhouetteSilhouette Shadow MapShadow Map Shadow VolumeShadow Volume Shadow Silhouette Shadow Silhouette

MapMap

SilhouetteSilhouetteGeometry



Shadow MapShadow Map



Shadow VolumeShadow Volume



Shadow Silhouette MapShadow Silhouette Map

Shadow Map + Silhouette InformationShadow Map + Silhouette Information



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AlgorithmAlgorithm

CriteriaCriteria AbstractAbstract InputInput Depth Test & Shadow ConfigurationsDepth Test & Shadow Configurations Generating the Silhouette MapGenerating the Silhouette Map Shadow RenderingShadow Rendering



CriteriaCriteria

The representation must guarantee a The representation must guarantee a continuous shadow boundary.continuous shadow boundary.

The information has to be easy to The information has to be easy to store in a texture.store in a texture.

There is only one silhouette point in There is only one silhouette point in each texel; only the last point will be each texel; only the last point will be stored.stored.



AbstractAbstract



InputInput

Shadow MapShadow Map Silhouette Edge (Geometry Silhouette Edge (Geometry

Information)Information)



Depth Test & Shadow Depth Test & Shadow ConfigurationsConfigurations



Generating the Silhouette Generating the Silhouette MapMap



Shadow RenderingShadow Rendering



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ResultResult

(Left) Standard shadow map. (Center) Shadow volumes. (Right) Silhouette map.



ResultResult



ResultResult

Scene fill: The number of fragments rendered to draw the scene without shadows.

Volume fill: The number of fragments drawn when rendering the shadow volume geometry.

Silhouette fill: The number of fragments that pass through silhouette.

O: The ratio of volume fill to scene fill is the overdraw factor O.

P: The ratio of silhouette fill to scene fill is the percentage P.



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ArtifactsArtifacts



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Conclusion & Future WorkConclusion & Future Work

Significantly improves the quality of Significantly improves the quality of shadow mapped images.shadow mapped images.

Simple and runs in real time.Simple and runs in real time. Finding the better silhouette Finding the better silhouette

representations out.representations out. Extending to soft shadow algorithms.Extending to soft shadow algorithms. Implementing the algorithm in Implementing the algorithm in

hardware.hardware.

shadow silhouette maps pradeep sen mike cammarano pat hanrahan stanford university

Documents

ratio of silhouette

silhouette point

right silhouette map

shadow volume geometry

continuous shadow boundary

soft shadow algorithms

center shadow volumes

number of fragments