FXAA (Fast Approximate Anti-Aliasing) is one technique that smooths out rendered jagged edges (“jaggies”) within scenes rendered in games.

FXAA is now a pretty old technique in game development, many other anti-aliasing ‘improvements’ have been developed since Timothy Lottes (of NVIDIA) developed FXAA around 2009.

FXAA though is a really efficient technique (and that’s what we need within the game engine – to give pretty good visual improvements without material impact on FPS/performance).

So, kind of went back to first principles with the post processing shader effect and referenced Mr. Lottes papers from 5 or so years ago – FXAA by Timothy Lottes / NVIDIA.

Still more tweaking to do, but the first test results are encouraging -the first image below is without FXAA and second is with FXAA switched on –   ignore the vignette – also applied this when FXAA was off to make sure I remembered which setting was on at the time :).

It’s a subtle change but quite clear (might be easier to see full size if you click on the images, but a zoomed in view below too) – look at the rails, the second image has a lot smoother rendering on the horizontal bars, still some jagged edges on the verticals, but have just started to tweak the tuning parameters, so hopefully they will improve too.

No noticeable FPS drops which is one of the main requirements (currently FXAA is merged with an existing shader pass). Everyone happy!