Hello

I rendered the julia fractal given in the docs

  julia_fractal {
   <-0.083,0.0,-0.83,-0.025>
   quaternion
   sqr
   max_iteration 15 // 8
   precision pow(8,10) // 15
  }

but I always get black spots and even black interrupted areas.
With enabled antialiasing the spots get somewhat melted to gray
which doen't look even better. Especially in animations the
gray blurred areas look bad a bit like "gray noise".
The Julia fractal is a beautiful thingy but is there a way to
rendere it with a smooth surface? Note the high precision!

PoV: 3.6.1 linux

Regards,
Sebastian

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> Note the high precision!

That's probably part of your problem, actually. Fractals are *very* busy
objects. Try lowering the precision and see how your julia gets smoother.
With high precision, POV-Ray interpolates less and you easily end up with
clouds of particles.

Regards,
Tim

-- 
"Tim Nikias v2.0"
Homepage: <http://www.nolights.de>

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Tim Nikias schrieb:
>>Note the high precision!
> 
> 
> That's probably part of your problem, actually. Fractals are *very* busy
> objects. Try lowering the precision and see how your julia gets smoother.
> With high precision, POV-Ray interpolates less and you easily end up with
> clouds of particles.

Nah, I dont't think so.
It seems to be related to floating point precision.
Altering the precision statement can make some holes
(what the black spots are actually) appear
and disappear while some are not affected at all.
These ones disappear below max_iterations=9 approximately.
They also look different. Mostly they have a linear edge
which moves in parallel to camera movement and disappears
at some angle just to reappear later (in animation) somewhere else.
There is an example in p.b.i. and there is an animation
rendering at the moment which I'll post later.

Regards,
Sebastian

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