Object Space EWA Surface Splatting: A Hardware Accelerated Approach to High Quality Point Rendering

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Object Space EWA Surface Splatting A Hardware
Accelerated Approach to High Quality Point
Rendering

• Liu Ren

Hanspeter Pfister
Matthias Zwicker
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Motivation

• Point-based graphics needs high quality texture
  filtering
• High quality point rendering lacks hardware
  support
• GPU performance outpaces CPU

Wolfman Geforce 4 demo
Pure Hardware Accelerated High Quality?
Yes!
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Related Work
Software Only Hardware Accelerated
w/o texture filtering Point Sample Rendering EURW 98 QSplat Siggraph 00, Point Set Surfaces IEEE Vis 01, Procedural Geometry EURW 01
w/ texture filtering Surfels Siggraph 00, Surface Splatting Siggraph 01, Efficient Surface Splatting EURW 02 Hardware-Oriented Point Rendering EURW 02,
Object Space EWA Splatting EG 02
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Point-based Surface Representation
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Surfel Rendering Splatting
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Surfel Rendering Screen Space EWA Filtering
reconstruction filter

• Elliptical Weighted Average (EWA) filtering
• EWA Splat low-pass filter warped
  reconstruction filter
• Screen space EWA splatting not supported by
  graphics hardware.

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Surfel Rendering Object Space EWA Filtering

• Tangent space resampling filter warped
  low-pass filter reconstruction filter
• View dependent filter

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Hardware Accelerated Point-based Rendering
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Challenges
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Two Pass Algorithm Overview
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First Pass Visibility Splatting Schemes
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Second Pass Handle View Dependent EWA Resampling
filter
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Normalization Issues
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Demo Checkerboard on Geforce 4 Ti 4600

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Demo Surfel Models on ATI Radeon 9700
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Demo Surfel Models on ATI Radeon 9700
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Demo Surfel Models on ATI Radeon 9700
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Demo Surfel Models on ATI Radeon 9700
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Performance with Phong Shading
Data Points 512 by 512 512 by 512 1024 by 1024 1024 by 1024
Data Points Geforce 4 Ti 4600 Radeon 9700 Geforce 4 Ti 4600 Radeon 9700
103K 21.1fps 29.0 fps 14.7 fps 24.7 fps
102K 18.6 fps 23.7 fps 9.8 fps 20.6 fps
273K 5.2 fps 8.6 fps 3.7 fps 8.3 fps
352K 4.6 fps 13.6 fps 3.6 fps 8.5 fps
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Conclusion

• New object space formulation of EWA surface
  splatting
• Completely hardware accelerated approach with
  negligible CPU involvement
• Benefits from GPU performance improvements

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Future Work

• Semitransparent point models
• View dependent BRDF shading
• Animated point models
• Optimization with upcoming hardware features

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Acknowledgments

• Jessica Hodgins, Paul Heckbert
• Micheal Doggett, Evan Hart, Jeff Royle
• Henry Moreton
• Jennifer Pfister, Wei Li, Wei Chen
• Http//www.cs.cmu.edu/liuren/research.htm