nVidia GeForce GT200 Series Anti-Aliasing Investigation

Image Quality (MSAA/CSAA/SSAA)

For the image quality comparison, I’ve chosen an outside scene from the original Far Cry. Since AA’s main benefit comes during movement, these images have been zoomed in order to better show differences. I’d suggest loading the images into separate browser tabs and quickly switching between them. Also ensure browser image scaling is disabled.

0x

2x

4x

8x

8xQ

16x

16xQ

8xS

16xS

32xS

2xAA and 4xAA both provide noticeable image quality gains across all four edges over 0xAA and 2xAA, respectively.

8x is slightly smoother than 4xAA on all four edges.

8xQ looks slightly smoother than 8x on edges 1 and 4, but slightly worse on edge 3.

16x is slightly better than 8xQ on surface 4.

16xQ has the best looking edge 3 of the four CSAA modes, but edge 4 looks slightly worse than 16x’s.

8xS is better than 8x on all four edges, and is about the same as 8xQ overall. However the benefits of full scene super-sampling come into play too; the tree in the top left corner is smoother, and also the hut’s straw roof texture gains definition and clarity. This increased sharpness provides contrary evidence to those that claim super-sampling blurs 3D scenes because in this instance it’s doing the exact opposite.

16xS is about the same as 16xQ on the four edges, but perhaps slightly better on edge 4. Compared to 8xS the roof texture gains even more clarity and the tree gets smoother too, courtesy of the super-sampling component increasing over 8xS.

32xS looks about the same as 16xS except with edge 4, where it’s slightly smoother. Thus 32xS provides the smoothest chair edge we’ve seen today. The tree and roof texture remain identical to 16xS because super-sampling component is the same with both modes.

It should be worth noting that the edges in this scene represent the best case for CSAA, so the scheme is allowed to reach its full potential. In other scenes however (such as shared polygon edges and/or stencil shadows), the image quality will be closer to its base multi-sampling level, so results may vary. In these instances, 8xQ provides a more consistent gain in image quality than either 8xAA or 16xAA. Nevertheless, CSAA still represents a clear upgrade over 4xAA.

Getting back to the tree, even though it received some AA from the xS modes, I’m still going to test it with TrAA at it was designed with exactly this kind of scenario in mind.