Christopher James Huff wrote:

> BTW, looking through the old Ray Tracing News archives, there's plenty
> of information about this...one interesting method was to make a hash
> value from the objects intersected and shadow rays. If the hash value
> changed from one pixel to another, either the set of objects hit
> changed, or the image passed into/out of shadow. Then the colors were
> compared, and the pixel was only antialiased if the hash changed and the
> color was different. No antialiasing the tail of a black cat on a
> moonless night, but only object/shadow edges were antialiased. Sharp
> edges in the texture were left alone...these guys apparently didn't use
> textures with sharp edges. ;-)

I do not like the idea of antialiasing only at objects frontiers.. as 
textures are certainly one of the most important thing with POV-Ray.

> This technique could be adapted to POV as a way of specifying different
> antialiasing parameters for object edges and textures...if the hash
> value triggers it, use one setting, but if the color difference is
> greater than a threshold (and the hash values are the same), use a
> different setting. If it could be further controlled...certain textures
> or objects using no antialiasing...it could make things like starfields
> much easier.

I do not know the povray source good enough for adding object specific 
features :(.

> This reminds me...are the colors clipped before or after antialiasing?
> It should be after...a "superbright" object (rgb > 1) should contribute
> more to a pixel than a dim (rgb 1) one.

I will look this up.

- Micha

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