2.31
Filter: FXAA

- 2.31.1. Overview
- 2.31.2. Implementation
- 2.31.3. Types

2.31.1
Overview
1
Fast Approximate Anti-Aliasing is a simple algorithm that attempts to detect and smooth aliasing in a color image. The algorithm works with only the color components of the image in question; no other per-pixel information or knowledge of the scene is required.
2.31.1.2 Without FXAA
2.31.1.3 With FXAA
2.31.2
Implementation
1
Unfortunately, information on the FXAA algorithm is sparse, and much of it has been lost to time. The original FXAA algorithm was published in a whitepaper by NVIDIA [28] and was severely optimized by the author on the suggestions of many mostly anonymous contributors. The latest published version of the algorithm (version 3.11) bears little resemblance to the original and no documentation exists on the changes. The 3.11 version of the algorithm is constructed from a maze of C preprocessor macros, and many different variations of the algorithm are possible based on how the parameter macros are defined.
2
The implementation of FXAA in the r2 package is a set of GLSL expansions of the public domain [29] Fxaa3_11.h header with a few minor modifications (unused parameter removals). Specifically, the PC algorithm is used, with quality presets (10, 15, 20, 25, 29, 39).
2.31.3
Types
1
In the r2 package, the FXAA effect is provided by the R2FilterFXAA type.

[28]
http://developer.download.nvidia.com/assets/gamedev/files/sdk/11/FXAA_WhitePaper.pdf
[29]
The included Fxaa3_11.h file bears an NVIDIA copyright, but was placed into the public domain by the original author.