Bill Pragnell nous apporta ses lumieres en ce 2007/09/21 05:42:
> "Kenneth" <kdw### [at] earthlinknet> wrote:
>> You're right. Of course, it's good for "focusing attention" on a particular
>> part of an image; but there are other, opposite uses for focal blur where
>> you want to "de-emphasize" an area (the foreground.) without affecting
>> anything else.  That's my primary reason for wanting an alternate type of
>> blur.
> 
> My personal experience of focal blur is not extensive, but what you describe
> was my goal in this image:
> 
>
http://news.povray.org/povray.binaries.images/thread/%3Cweb.4669ae9cb060a40a7e595fbb0%40news.povray.org%3E/
> 
> The background (the object in focus - the brick structure) is not exactly an
> infinite expanse, but it certainly occupies most of the scene's depth. Is
> this the kind of thing you meant?
> 
>>> The way POV-Ray handles this now is rather cumbersome.  If I set 4x4
>>> anti-aliasing, and uses a 4x4 area light, the area light is fully
>>> sampled for each sample of the spatial anti-aliasing, and if I throw in
>>> 10x oversampling for motion blur, then the scene takes 2560 times as
>>> long as a scene with no area lights, anti-aliasing, or motion blur.
>> OW!  That hurts.
>>
>> Thanks for the reply; your explanation of the PIXAR method is fascinating.
>> Think a similar methodolgy could make it into POV?
> 
> I've noticed quite a few people who use focal blur regularly say they just
> don't bother with AA - the focal blur does the job for them. Not quite what
> you're asking but it does bring potential render times down a little!
> 
> :)
> 
> 
Actualy, POV-Ray don't allow focal blur and AA in the same render. Use focal 
blur and regular AA get disabled.

-- 
Alain
-------------------------------------------------
We did not raise armies for glory or for conquest.
Thomas Jefferson

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