Matthew Pace wrote:
> I have decided to do a series of glowing boxes, I dont know if I stole 
> this from anyone, if so, please let me know, and I apologize.  Here is a 
> partial rendering of the first one, with radiosity off (looks better 
> with it on, duh) and some artifacts that I believe are from AA.  If you 
> can tell me how to fix that, I would be quite thankful.  Its currently 
> AA adaptive .4 threshold, level 5 recursion, and .1 jitter.  I have a 
> lot going one because it was highly aliased, espescially at large 
> resolutions.  You can notice it at the edge facing the camera, the line 
> between dark and light is not straigt.

You seem to have a poor understanding of the AA parameters, maybe I can 
help...

The threshold defines how much difference there has to be between two 
pixels before POV-Ray will attempt to antialias them, treating each 
pixel as having RGBvalues between 0 and 1; this value can range from 0 
(AA everything except areas of no changes whatsoever) to 3 (only AA 
divisions between pure white and pure black - in effect, nothing). A 
good value to use for this while testing (if for some reason you're 
testing with AA on) is .2 or .3, which is enough to get the effect of AA 
but not enough to guarantee smoothness. For final renders, consider 
using .1 or less.

The recursion defines how closely POV-Ray looks for edges; the higher 
the recursion, the more supersamples it takes in order to define edges 
and/or small details. In actual practice, a value of 2 is plenty for 
test work, and anything above 4 is likely to be a waste; if you're not 
getting enough detail at 4, you're probably better off rendering at a 
higher resolution.

Jitter jitters the supersamples, essentially adding a small amount of 
noise to antialiased areas, and should probably be avoided as a general 
rule (IMO). In your case, I would say that jitter is responsible for the 
"artifacts" you describe. Try setting it to 0.

You might also consider moving the camera or objects slightly so that 
the division between the front faces falls along natural pixel 
boundaries, if having the antialiased edge there REALLY bothers you.

-Xplo

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