POV-Ray : Newsgroups : povray.bugreports : Something fishy with Julia_Fractal : Something fishy with Julia_Fractal Server Time
4 Jul 2022 02:41:32 EDT (-0400)
  Something fishy with Julia_Fractal  
From: Sven Geier
Date: 2 May 2011 18:25:00
Message: <web.4dbf2e26b56a53c15b4449250@news.povray.org>
In the following, note the parameter cam_distance, which merely scales the
distance of the camera from the origin (along the given vector). Paste this into
your POV-ray as-is and render it with the number in there (cam_distance=0.7)

Make a copy of the resulting image. Now change cam_distance to 0.5 and render
again. Compare with the previous image.

What I would expect to happen is that I'd see the object somewhat
closer-up (and thus lose some of it around the edges). Which does in fact
happen. However in addition the "ring" in the center of the object that was wide
open before closes in the front.

Surely a change in the shape of a rendered object with camera location would be
a bug, no?

# == POV-Ray file begins here
#version 3.7;

#include "functions.inc"
global_settings { assumed_gamma 2.2 }

#declare cam_distance = 0.7;

camera { angle 45
  location  <10, .5, 0> * cam_distance
  look_at   <0, 0,  -.5>
  right     x*640/400
  rotate <0,-5,0>
}

light_source { 0 color rgb 1 spotlight
  translate <80, 80, -40> point_at 0 }
light_source { 0 color rgb <2,1,0> translate <-20, 40, -20> }
sky_sphere { pigment { gradient -y }}

julia_fractal{ <-1.483,0,-0.0,-0.025>
   quaternion sqr max_iteration 12 precision 500
   texture{
     pigment{ color rgb 0.7}
     finish { phong .6 reflection {.6 metallic }}
   }
   scale 3
   rotate <0,110,-45>
}
# == POV-Ray file ends here


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