In article <3ef227de@news.povray.org>, Warp <war### [at] tagpovrayorg> 
wrote:

> > One of the other things that needs to be done is to do clipping after 
> > the antialiasing. An extremely bright object should contribute more to a 
> > pixel than just a white one. However, because simple clipping is used, 
> > this makes super-bright objects appear unantialiased...
> 
>   A more (photo)realistic effect would be that this kind of ultrabright
> spot bleeds brightness to the surrounding pixels.

This would be more photorealistic than an ordinary antialiased image, 
but is a separate effect from antialiasing.


>   However, the algorithm for implementing this might not be trivial nor
> fast...

Actually, it was implemented as a post-process filter in the old 
MegaPOV, and there has been quite a bit of discussion about it recently. 
Basically, you make a blurred version of the image using the unclipped 
values, and combine it with the unblurred version. The blurred version 
simulates the light scattered within the eye (or camera film), the 
unblurred version is the unscattered light, so you just weight them 
appropriately and average them.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

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