Daniel Nilsson wrote:
> 
> There seems to be many arguments on what's right in this thread but I (who
> normaly just reads this group) want to give you all my view on the topic.
> I'm not saying that this is more "right" or something like that, all is
> IMHO.
> I have for several years planned making my own raytracer and have though
> long about the antialias problem (having had the clipping before/after aa
> problem with pov). I have come to the conclusion that the super sampling
> should be done on unclipped values on the argument that it is really an
> approximisation to an intergral over the pixel. This gives the expected
> result for small bright objects such as stars. The problem is that edges of
> very bright object get alias problems, and that's not the expected result.
> With a digital camera such an edge will look soft (at least partly) because
> imperfections in the lenses and the air will make the bright light "bleed".
> My plan is to simulate this bleeding in a post process step before the
> [...]

No. While you are perfectly right that a digital camera image contains 
blur because of the imperfections in the optical system and elsewhere 
that is not the reason why there are no aliasing effects.  These won't 
occur even with a perfect optical system because - as Tek correctly 
describes - a digital camera sensor collects the incoming energy and 
therefore does a true integration over the pixel area.

Using post processing to make a render look more like a photograph is 
certainly useful but you should not make the mistake to think this has 
anything to do with antialiasing.

Christoph

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