The color at the end of this cylinder appears undefined, although if I
understand the documentation correctly, it should be Red.  Can anyone else
verify this result?

Please e-mail me directly, since I don't check the news very often.

thanks.

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Attachments:
Download 'gradient_bug.pov.txt' (1 KB)

Carl Osterwisch <cos### [at] biocomarizonaedu> wrote:
: The color at the end of this cylinder appears undefined, although if I
: understand the documentation correctly, it should be Red.  Can anyone else
: verify this result?

: Please e-mail me directly, since I don't check the news very often.

  This is NOT the right place for asking "is this a bug?".
  I haven't checked if this is a bug or not, but this article should
definitely have been sent to povray.general or .newusers or other similar,
not here.

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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On Thu, 5 Aug 1999 10:49:03 -0400, "Carl Osterwisch"
<cos### [at] biocomarizonaedu> wrote:

>Please e-mail me directly, since I don't check the news very often.

  Hi, Carl. Please read, "How to post bug reports", in the group
povray.announce.frequently-asked-questions.

  After you have read that message, please then read, "Where can I post my
binary or text file?", which may be found in the same group, p.a.f-a-q.

  Thank you for helping keep our newsgroup organized.

-- 
Alan
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Carl,

the gradient pigment spans from one end of the cylinder to the other.
In a perfect world this would be just fine, but precision errors yield
the result you are seeing. POV finds the surface of the cylinder to be
something like z - A_Very_Small_Error and the pigment is found to be z
+ Another_Very_Small_Error, and these errors are random, so you see a
spotted surface. This is a variation of the coincident surfaces
problem, see Warp's VFAQ.

Here're several solutions of the problem:

a) scale the gradient pigment a bit up, like scale 1.00001
b) use the planar or marble pigments instead of gradient
c) scale down the cylinder a bit (like 0.999999) before applying the
pigment

HTH.


Peter Popov
ICQ: 15002700

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