POV-Ray : Newsgroups : povray.general : julia_fractal : julia_fractal Server Time
7 Jul 2022 03:39:18 EDT (-0400)
  julia_fractal  
From: nested
Date: 2 Nov 1999 10:06:17
Message: <381efde9@news.povray.org>
hi, i expect this has been addressed before, but i've looked around and
haven't seen it anywhere.  i'm using povray 3.1g on a windows 98 machine.
amd k6-2 366 mhz, 32 meg ram..  I've been rendering mostly quaternion julia
fractals since i got povray, and i've encountered an unpredictable bug.
sometimes a fractal will look like part of it is clipped.  this could be a
planar slice or a sort of unpredictable scoring.  when i've tried, rotating
the fractal will get rid of it.  the error in the scene i included leaves
the affected part of the fractal in what i assume is the proper shape, but
it looks like static.  the error does not appear if this specific fractal is
viewed head on.  however, i've seen it occur with no 3d rotation and a non
default 4d normal.  in this case, if the camera is rotated around the
fractal instead, or if the fractal is expressed as the intersection between
the fractal and a larger sphere and is then rotated, the error still occurs.
i was shooting in the dark for solutions.
  does anyone know if there are any patches that fix this, or if there are
any quick and dirty ways to get around it in pov?  has this bug been brought
up before?  i want to make animations that involve rotation, so this could
be hard to workaround, and sometimes, i prefer a certain angle just because
it looks better, and can't get it.  i think pov is incredibly powerful, and
can't get enough of how easy it is to create with
it.  with all of that promise, this is a little frustrating.

here's the code.

camera{
  location <0,0,-2.3>
}

light_source{
  <0,0,-2.3>
  color rgb 1
}

julia_fractal{ 
  <-1.154166666666666, -0.25, 0, 0>
  max_iteration 10 
  quaternion
  sqr   
  precision 2000
  pigment{rgb <1,.3,.3>}
  rotate<0,80,0>
} 

thanks.
Michael.


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