Abstract
We present a novel algorithm for the rendering of hard shadows cast by a point light source. The well-known Z-pass method for rasterizing shadow volumes is not always correct. Our algorithm, which we call ZP+, elegantly corrects Z-pass defects. ZP+ takes advantage of triangle strips and the fast culling capabilities of graphics hardware not available to conventional robust methods like Z-fail. While Z-fail can be up to 80% slower than Z-pass, our new method ZP+ is typically less than 10% slower than Z-pass. Finally, we compare the three methods. When a scene is geometry-bound, ZP+ is always faster than Z-fail. We also explain why, in some situations, Z-pass (hence ZP+) is surprisingly slower than Z-fail on more recent graphics hardware.
Original language | English (US) |
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Pages | 195-202 |
Number of pages | 8 |
State | Published - 2005 |
Event | I3D 2005: ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games - Washington, DC, United States Duration: Apr 3 2005 → Apr 6 2005 |
Other
Other | I3D 2005: ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games |
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Country/Territory | United States |
City | Washington, DC |
Period | 4/3/05 → 4/6/05 |
Keywords
- Graphics hardware
- Real-time rendering
- Shadow volume
- Stencil shadows
ASJC Scopus subject areas
- Software
- Human-Computer Interaction
- Computer Graphics and Computer-Aided Design