Aggregate G-Buffer Anti-Aliasing

in Proceedings of the ACM Symposium on Interactive 3D Graphics and Games 2015 (I3D'15)

Cyril Crassin, NVIDIA
Morgan McGuire, NVIDIA and Williams College
Kayvon Fatahalian, Carnegie Mellon University
Aaron Lefohn, NVIDIA

Paper (41 MB PDF)
Low-res Paper (2 MB PDF)
Slides (5 MB PDF)
Slides (34 MB PPT)
Video results (YouTube)
Video results (452 MB MP4)


We present Aggregate G-Buffer Anti-Aliasing (AGAA), a new technique for efficient anti-aliased deferred rendering of complex geometry using modern graphics hardware. In geometrically complex situations, where many surfaces intersect a pixel, current rendering systems shade each contributing surface at least once per pixel. As the sample density and geometric complexity increase, the shading cost becomes prohibitive for real-time rendering. Under deferred shading, so does the required framebuffer memory. AGAA uses the rasterization pipeline to generate a compact, pre-filtered geometric representation inside each pixel. We then shade this at a fixed rate, independent of geometric complexity. By decoupling shading rate from geometric sampling rate, the algorithm reduces the storage and bandwidth costs of a geometry buffer, and allows scaling to high visibility sampling rates for anti-aliasing. AGAA with 2 aggregate surfaces per-pixel generates results comparable to 8x MSAA, but requires 30% less memory (45% savings for 16x MSAA), and is up to 1.3x faster.



  author = {Cyril Crassin and Morgan McGuire and Kayvon Fatahalian and Aaron Lefohn}
  title = {},
  month = {February},
  year = {2015},
  pages = {11},
  booktitle = {Proceedings of the ACM Symposium on Interactive 3D Graphics and Games},
  location = {San Francisco, CA},
  url = {}