Forced FXAA. How does it Work?
Written by: ricerocketlondon1 - 03:51 Nov-28-2016

FXAA is a type of anti aliasing. If you don't know much about anti aliasing here is a link to a pretty good explanation note that also include's how FXAA works as well. This brings us to the next thing which is what it stands for Fast Approximate anti aliasing. Now older games don't usually support FXAA right out of the box. Doing some research I discovered this PDF which is dated February 2009, and copyrighted in 2010. So I think it is safe to say that the earliest you might see an application with FXAA is 2009. So Lets bring up the game that inspired me to write this Left 4 Dead. Left 4 Dead does not support fxaa. Neither does it sequel. I was playing some Left 4 Dead 2 at 1080p when I noticed some very noticeable aliasing. It was at that point I remembered I had no Anti Aliasing on! Shortly after I decided to head to one of my dustier programs. The Nvidia control panel, where I went into the Manage 3D settings, (which by the way does not mean 3D as in 3D mode, but 3D application's) and headed to L4D2's settings tab. There I switched the FXAA option to forced on. I rebooted the game(just to ensure no glitches occur and that the setting would activate) and began to play with far less Aliasing, however I noticed some oddities.  FXAA was effecting some non game elements. Which caused my FPS counter to display funny(note that the steam counter is not game based but steam overlay based) Now in other games GTA V for instance this didn't occur. So I decided to see if I switched off the FXAA and see if the in-game MSAA would do this. It did not. This made me realize that the FXAA didn't force the application it's self to FXAA mode but the entire screen to have an FXAA effect when that window was up. Upon reflection I should have tested more than just windowed mode. Regardless I was right in game MSAA didn't effect it, however NCP forced MSAA did. In the end this honestly makes a lot of sense. I'll use GTA 3 for an example. GTA 3 has no built in Anti Aliasing the only way to play it with any AA is to use forced AA through a third party. (does amd have a control panel that allows you to force AA? I haven't owned an AMD card since the days of AGP) GTA 3 has no code for it written anywhere. This means that the NCP would have to apply it to everything on the screen as it's likely that it has no way of telling whether or not an older application is using a separate overlay for displaying information. Such as the way Thief 2 technically opens another window when looking at a message or a map or the pause menu which is why fraps can't record them. Now I you post what you think of this in the comments below. You never know if I misread the compiled information that I had gathered. A favorite quote of mine. "Believe only half of what you see and none of what you hear."- Either Edgar Allen Poe or Benjamin Franklin. I heard it once in a class, and the instructor said that it was Franklin however I've seen several pictures claim Poe and several others claim Franklin. Regardless I believe it to be a valid quote.

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10:43 Nov-28-2016

Ty for info mate!