250 likes | 475 Views
SIGGRAPH 2010 Reducing Shading on GPUs Using Quad-Fragment Merging. Kayvon Fatahalian Solomon Boulos James Hegarty Kurt Akeley William R. Mark Henry Moreton Pat Hanrahan JAEHYUN CHO. Outline. Motivation System Results Conclusion. Highly Detailed Surfaces.
E N D
SIGGRAPH 2010 Reducing Shading on GPUs Using Quad-Fragment Merging Kayvon Fatahalian Solomon Boulos James Hegarty Kurt Akeley William R. Mark Henry Moreton Pat Hanrahan JAEHYUN CHO
Outline • Motivation • System • Results • Conclusion
GPU Rendering Pipeline • Quad-fragments • Fragments in 2 x 2 pixel blocks • Quad pipeline in current GPUs • Generate quad-fragment per triangle
Quad-fragment Shading How many shadings occur per pixel?
Pixels at triangle boundaries are shaded multiple times Over Shade
Main Idea • Goal • Shade once per pixel • Solution • Merge quad-fragments
Quad-fragment Merging Pipeline Reduce # of quad-fragments
Anti-aliasing Effect Triangle Mesh Final Pixels Anti-aliasing
Aliasing Effect on Naive Merging Triangle Mesh Final Pixels Aliasing
Conditions for Merging • Triangles should be connected via edges • Triangles have the same sideness • Either front or back-facing
Visual Quality Merging No merging
Shading Computations Merging No merging • 1/2 pixel size triangles • Merging : 8.5x less shading
Conclusions • Contribution • Faster than No merge GPU rendering • No radical changes to current pipeline • Limitation • Motion/focal blur
Q & A Thank You