Thorsten Froehlich" <tho### [at] trfde> wrote ...
>
> It is not like somebody in the team woke up one day and said: Hey, what am
I
> going to do today?  Ah, yes, I know, I am going to "break" anti-aliasing
to
> screw up Rune's scenes.
>
> It is a clear correction to previously incorrect behavior.  Previously
> POV-Ray was broken, it no longer is.
>

I realize I'm jumping into this conversation very late, but...

I have to disagree.  I think the previous behavior was actually correct and
the new behavior is incorrect.

Let me explain why:

As I understand it, anti-aliasing is intended to simulate the effect of
downsampling an image rendered at a higher resolution.  The whole point of
AA is to remove the "aliasing" jaggies.  That is its sole purpose.

So, if you were to perform AA by hand by rendering the image at a higher
resolution and then downsample it using an external paint program, the
downsampling is clearly occurring after clipping and gamma correction.  As
such, POV should simulate this behavior.  I am confident that this was done
on purpose and not by accident

So, my "proof" goes like this:
1)  AA is intended to simulate downsampling of a rendered image
2)  Downsampling of a rendered image is performed after clipping and gamma
correction
Conclusion:  AA should be performed after clipping and gamma correction

The important observation here is that, IMHO, anti-aliasing was NEVER
intended to simulate anything that happens in a camera.  It was intended to
simulate something that happens in a 2D paint program.

-Nathan Kopp

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