Samuel Benge wrote:
> Rune wrote:
>> Unfortunately, since POV-Ray 3.6, when using really high contrast,
>> the effects looks aliased even if antialias is used. This is because
>> of the controversial decision to make POV-Ray do clipping *after*
>> antialiasing rather than before. In POV-Ray 3.5 it looked perfect.
>> However, you can always render at a higher resolution and scale down.
>>
>> Rune
>
> Gah, I don't know why it was changed!

Thorsten (I believe it was) explained something along the lines that the 
pixels in the raytraced image should simulate the light-sensitive cells in a 
digital camera, which covers an area, but which can be over-exposed even if 
just one small sub-pixel dot is really bright. In effect, it meant that you 
can create a scene with stars in the sky that are much smaller than one 
pixel but still show up if they are sufficiently bright.

This then is the justification for a feature that makes all very bright 
things with sharp edges look jagged.

> Speaking of odd aa behavior, I don't even use +am1 anymore because of
> the strange artifacts. Is that also due to post-clipping of averaged
> samples?

Hmm, I don't know...

Rune
-- 
http://runevision.com

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