POV-Ray : Newsgroups : povray.beta-test : Media_attenuation bug? (Windows) : Media_attenuation bug? (Windows) Server Time
29 Jul 2024 14:23:54 EDT (-0400)
  Media_attenuation bug? (Windows)  
From: StephenF
Date: 26 Apr 2002 22:53:47
Message: <3CCA1221.30307@whoever.com>
I suspect this may be related to the previous posts about 
media_attenuation, but since the poster didn't provide much detailed 
info, and this is for the Windows version rather than Linux, I thought I 
should post it separately.

When adding media_attenuation on to a point light source, I received the 
following error message:


   The POV-Ray core rendering code caused an access violation exception.

   It is STRONGLY RECOMMENDED that you save your work and exit the 
  program before attempting the render again.

   (Note that if internal structures have been damaged POV-Ray may crash 
immediately after you click OK).


The following is a simple scene which recreates the error:


camera {
   location <0, 0, -1>
   look_at  <0, 0, 0>
   rotate <0, -10, 0>
   translate <1, 0, -3>
}

media {scattering {2, <.05, .05, .05> extinction .06}}

light_source {
   <3, 14, 20>
   rgb <1, 1, 1>
   media_attenuation on
}


Changing the point light to a spotlight causes it to render without a 
problem, by adding the following code to the light_source block:

   spotlight
   point_at <0, 3.5, 10>
   radius 20
   falloff 20


As far as I can tell from the documentation, while it seems to be 
preferred to use a spotlight with media_attenuation, a point light 
should work as well.

The sample scene renders without a problem in 3.1, with and without the 
spotlight code.

Can anyone confirm?

Win98 SE; Athlon 1.4GHz; 512 MB DDR-ram; Pov-Ray for Windows 3.5 beta 
Release Candidate 2


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