Fast approximate anti-aliasing

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Three powerlines, a jagged one followed by two smoother ones.
Comparison between (from left to right)Without anti-aliasing, 4x MSAA, and FXAA.

Fast Approximate Anti-Aliasing (FXAA) is an anti-aliasing algorithm created by Timothy Lottes under NVIDIA.[1]

Advantages[edit]

  • Does not require large amounts of computing power, achieved by smoothing jagged edges ("jaggies")[2] according to how they appear on screen as pixels, rather than analyzing the 3D models itself as in conventional anti-aliasing.[1]
  • Smooths edges in all pixels on the screen, including those inside alpha-blended textures and those resulting from pixel shader effects, which were previously immune to the effects of multisample anti-aliasing (MSAA).[3]

Basically the simplest and easiest thing to integrate and use.

Timothy Lottes[4]

Disadvantages[edit]

  • Textures may not appear as sharp if they are included in the edge detection.
  • Must be applied before rendering the HUD elements of the game, lest it affect them too.

Processes[edit]

Building image with highlighted edges.
FXAA processing illustrations

The processes of FXAA are listed as follows:

  • Find all edges contained in the image.

Finding edges is typically a depth-aware search, so that pixels which are close in depth are not affected. This helps to reduce blurring in textures, since edges in a texture have similar depths.

  • Smooth the edges.

Smoothing is applied as a per-pixel effect. That is, there is no explicit representation of the edges. Rather, the first step is a depth-aware edge filter, which marks pixels as belonging to edges, and the second step filters the color image values based on the degree to which a pixel is marked as an edge.

References[edit]

  1. ^ a b Lottes, Timothy (February 2009). "FXAA". NVIDIA. Retrieved 29 September 2012. 
  2. ^ Wang, James (March 19, 2012). "FXAA: Anti-Aliasing at Warp Speed". NVIDIA. Retrieved January 3, 2013. 
  3. ^ Atwood, Jeff (December 7, 2011). "Fast Approximate Anti-Aliasing (FXAA)". Coding Horror. Retrieved September 30, 2012. 
  4. ^ Lottes, Timothy (September 3, 2011). "NVIDIA FXAA". Retrieved September 30, 2012.