Archived from groups: alt.comp.periphs.videocards.ati (
More info?)
Well.. I'm sure there not doing AA with shaders
I don't know the specifics of how Nvidia and ATI have optimized their FSAA
OGSS implementations. I don't think anything revolutionary has occured. But!
it does seem like there is some magic going on somewhere doesn't it? The
performance hits just aren't what you'd expect.
--
Tony DiMarzio
djtone81@hotmail.com
djraid@comcast.net
"Asestar" <a s e s t a r @ s t a r t . n o> wrote in message
news:OyXdc.78234$BD3.9071264@juliett.dax.net...
> Thanks for reply. That does explain it.
> However I tought that with this new breed of gpu's everyone is talking
about
> supperior performance with AA enabled, compaired to previous gen gpu's.
>
> Example: a r8500/gf4ti4200 would perform somewhat same as r9600/Fx5600 in
> certain cases, when AA is not enabled. However enbling AA makes newer
cards
> so much faster than the previous generation.
>
> This led me to believe that there are some revolutionary change in AA
> techinique with new DX9 cards. Maybe they use some kind of pixelshader
> programming or whatever to do AA? Guess not then.
>
>
> "Tony DiMarzio" <djtone81@hotmail.com> wrote in message
> news
a6dnQcHPcMOrOXd4p2dnA@comcast.com...
> > Actually, the Voodoo5 used RGSS/JGSS in it's FSAA implementation. Oh..
> > RGSS=Rotated Grid Super Sampling, JGSS=Jittered Grid Super Sampling.
> Rather
> > than render the image at 4 times the resolution (upsample) to the
> offscreen
> > buffer and scale it back down (downsample) while averaging the subsample
> > data around each pixel (this is OGSS or Ordered Grid Super Sampling),
RGSS
> > takes subsample pixel data at points of random rotation around the
pixel.
> >
> > There are religious wars even still over which implementation is better
> from
> > a tech standpoint and from a practicality standpoint... RGSS or OGSS....
> but
> > no one will dispute the superior IQ afforded by RGSS.
> >
> > Anyway... 3dfx used RGSS. All other manufacturers (ATI and Nvidia) used,
> and
> > AFAIK still do use, OGSS.
> >
> > Correct me if I'm wrong, but I'd assume all ATI cards are doing OGSS.
> >
> > --
> > Tony DiMarzio
> > djtone81@hotmail.com
> > djraid@comcast.net
> >
> > "Asestar" <a s e s t a r @ s t a r t . n o> wrote in message
> > news:t1Hdc.78174$BD3.9039327@juliett.dax.net...
> > > I remember from voodoo5 days that AA filtering was made possible by
> > drawing
> > > an image at high resolution, say 4 times the normal display res. and
> then
> > > scaling it down, thus eliminating the jaggies and getting smooth
> picture.
> > > This however was a very slow process.
> > >
> > > Can someone tell me is it the same process in current DX9 cards, like
> > 9600,
> > > 9700, 9800 and 5700 5900?
> > > Also does radeon8500 uses the same methos?
> > >
> > >
> >
> >
>
>
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