> No, do I mean unfortunately. Clipping before antialiasing is the wrong
> way to fix this problem. Small, intense sources get completely wiped
> out.

Because they're too small to be accurately represented in the final image
resolution. Just because they're intense doesn't mean they should become a
full pixel in size. This could end up producing different results depending
on what the final resolution is.

> Antialiasing supersamples the scene, not some virtual model of an
> image file in a format that's limited to a tiny dynamic range.

Antialiasing supersamples the scene, but it must take into account that the
final output will have limitations such as a finite dynamic range. The
mysterious "format" you refer to is the same as the actual format of the
final image, which is important. By clipping before averaging, anti-aliasing
produces the effect of rendering at an infinite resolution and then resizing
smaller, which is exactly what it's supposed to do.

I admit that I do see some logic in your argument - clipping before
averaging does feel artificial to some extent. However, the fact that
clipping after averaging would produce jagged edges on bright objects causes
me to believe that it would be much more useless than clipping before
averaging.

In any case, I'd appreciate if someone who's done a significant amount of
research on the topic could step in and tell us *why* POV-Ray does it the
way it does, and maybe what other popular 3D apps do, and why it is or is
not correct.

 - Slime
 [ http://www.slimeland.com/ ]

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