[Nouveau] Jittered antialiasing.

[Ove Karlsen]

In doom 3, there is a function called "jitter the subsampling matrix" 
(r_jitter)

I thought about doing an improved version of this, but I lack the 
expertise in driver development. But I share the idea with you, so that 
you may implement it, as a lowest resource antialiasing.

Carmack modulates the subsampling with white noise. That gives a 
psychovisual effect, that is a bit noisy, because of low-frequency 
variations. This can be improved by modulating with highpassed noise 
instead.

Also the technique can be improved by blending frames, say 1 frame is 
blended with 30% of second, 20%¤ of third 10% of fourth. And probably no 
more than that. Ratios and highpass should be tunable also. Maybe a 
lowpass on the noise would be good too, to remove extreme high-freqency.

Then you get jittered antialiasing, that combines several frames of 
different subsampling, to an average psychovisual effect, of higher 
resolution, and antialiasing.

Combining it with just a little smoothing from 2xMSAA and 2xAniso, is 
probably perfect. 2xAniso can be sharpened up with -0.5lodbias, and then 
it gives a smoother/more natural result when close, than higher aniso, 
and still sharp at distance.

Also -  Great performance in games, low latency, fast desktop:

A lot of people have been talking about these things lately. These 
things are already solved, and I sum them up, on my blog, as I have been 
researching the same, for quite some time. : 
http://paradoxuncreated.com/Blog/wordpress/?p=2268

John Carmack talks about not being able to run doom 3 at 60fps on 
consoles. So it runs at 30.

I am now running it at 72, with LOW Jitter (constant gliding framerate).
And that is even on what is today a modest dualcore 2.5ghz + a gtx 280.

So this is what you want.

-- 
Fred være med deg / Peace Be with You,
Ove Karlsen
http://www.paradoxuncreated.com