NVIDIA FXAA is slightly simplified version of Full Screen Anti-Aliasing(FSAA), that gives higher rendering speed and rather clear image. New aliasing method works as a single-pass post processing filter, providing high rates for AA at lower costs of hardware resources. Compared to traditional AA filters, NVIDIA FXAA stands out by using less memory and showing high performance at the same time.
FXAA algorithm is based on scalar estimates of luminance for shader logic of a non-linear RGB color data. Filter implementation requires selection from one of the example presets:
- Preset 0 has the highest performance and lowest quality. It simply breaks the aliasing on edges and applies a lower quality sub-pixel aliasing removal filter. This preset is not designed to be practical, but rather to show the lower limits of the tunable parameters.
- Preset 1 extends the end-of-edge search radius, adds the high quality sub-pixel aliasing removal filter, and increases the effected local contrast range. This preset is designed for highly performance constrained situations like high resolution mixed with laptop GPUs.
- Preset 2 is a good default for high performance but still shows some artifacts do to the end-of-edge search acceleration. This preset decreases the search acceleration, increases the end-of-edge search radius, and increases the effected local contrast range.
- Preset 3 is the default, good performance and high quality without artifacts: end-of-edge search acceleration is turned off.
- Preset 4 and higher continue to increase the end-of-edge search radius. The improved quality is marginal for the increase in cost. These presets are designed to show the upper limits of the tunable parameters.
FXAA is fully compatible with DirectX 9+, OpenGL and 3D technologies while offering direct in game integration.
First games to actual have this new feature are Duke Nukem Forever and F.E.A.R. 3. According to data published by Jacob Freeman, Product Manager at EVGA, the use of FXAA in F.E.A.R. 3 has resulted in 30% performance boost compared to dual-pass FSAA filter.