anti-aliasing in screenshots

G

Guest

Guest
Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

If i remember correctly, there is actually a reason why anti-aliasing does
not show in some screenshots for games. Has something to do with how the
whole process works. I hear people complaining about complete lack of
anti-aliasing in screenshots, even when the game itself is running at 4x AA.
Can someone explain this to me in more detail?
 
G

Guest

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Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

Spaceman wrote:
> If i remember correctly, there is actually a reason why anti-aliasing does
> not show in some screenshots for games. Has something to do with how the
> whole process works. I hear people complaining about complete lack of
> anti-aliasing in screenshots, even when the game itself is running at 4x AA.
> Can someone explain this to me in more detail?
>
>

This was mostly a problem when NVIDIA switched to post-processing
effects (such as a gaussian blur to Quincunx AA or image sharpening) in
the Geforce FX. Unless you captured the framebuffer, you couldn't see
antialiasing in the screen cap. Here's one of the original stories that
started it:

http://www.hardocp.com/article.html?art=NDIxLDQ=

I can't be sure but I think with current drivers, NVIDIA allows even
PrintScr to capture the entire framebuffer. I'm not sure if it was only
an issue with FX's or if my 6600GT does it too.

The reason for the change in AA methods is two fold. First, doing much
of your AA and blending as a post process saves a lot of fill rate. And
second, this is conjecture, but NVIDIA acquired some of SGI's
intellectual property a while back and one technique they used in
hardware like the r4300 (N64) was a color-matching antialiasing method
done almost "for free" "on-the-out" just as pixels were leaving the
framebuffer. I think Quincunx incorporates some of this in its method.
QC AA has certainly changed visually from the GF3 to GFX and GF6.