High!

Alain wrote:

> You have TWO (2) medias. An emissive one and a scattering one.

Now I removed the emissive media...

> You did NOT reduce the density of your scattering media, and that is 
> your problem.

After I adapted the scattering media density reciprocally to the scale 
(i. e. 1/36800) I got extremely faint transparent rings - both with and 
without absorption 1/36800, see first two images.

When I increased scattering density to 1/368, the rings became more 
visible - but still almost black on the unlit side, with some bizarre 
geometry showing up on the planet's night side (see third image)!

Could this be an effect of using filter in the color_map?

Here is the code for the last image:

global_settings
{
   max_trace_level 10
}

union
{
   sphere
   {
     0, 1
     texture
     {
       pigment { color rgb <0.6, 0.4, 0> }
       finish { ambient 0.02 diffuse 1 brilliance 0.8 }
     }
   }
   difference
   {
     cylinder
     {
       <0, -0.001, 0>, <0, 0.005, 0>, 3.68
     }
     cylinder
     {
       <0, -0.0011, 0>, <0, 0.0011, 0>, 1.75
     }
     hollow
     pigment { rgbt 1 }
     interior
     {
       media
       {
         // emission 1/36800
         scattering
         {
           5, 1/368
           // eccentricity -0.4
           // extinction 1
         }
         // absorption 1/36800
         density
         {
           cylindrical
           color_map
           {
             [0 rgbf <1, 0.8, 0.7, 0.2> ]
             [0.1 rgbf <1, 0.8, 0.7, 0.2> ]
             [0.1 rgbf <0.1, 0.3, 0.1, 0.5>]
             [0.17 rgbf <0.1, 0.3, 0.1, 0.5>]
             [0.17 rgbf <0.85, 0.89, 0.94, 0.3>]
             [0.18 rgbf <0.85, 0.89, 0.94, 0.3>]
             [0.18 rgbf <0.99, 0.93, 0.45, 0.4>]
             [0.26 rgbf <0.99, 0.93, 0.45, 0.4>]
             [0.26 rgbf <0.5, 0.23, 0.61, 0.5, 0.4>]
             [0.36 rgbf <0.5, 0.23, 0.61, 0.5, 0.4>]
             [0.36 rgbf <1, 0.92, 0.93, 0.3>]
             [0.45 rgbf <1, 0.92, 0.93, 0.3>]
             [0.45 rgbf <0, 0, 0, 1>]

           }
           scale 3.68
         }
       }
     }
   }
   rotate <2, 7, 0>
   scale 10000
   translate z*50000
}


light_source
{
   <500000, 2500, 5000>
   color rgb 1
}

camera
{
   location <1.5, 1.5, 0.12>
   look_at 1.5
   angle 60
}

See you in Khyberspace!

Yadgar

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Download '2009-11-25 media test, take 44.jpg' (8 KB) Download '2009-11-25 media test, take 45.jpg' (8 KB) Download '2009-11-25 media test, take 46.jpg' (10 KB)

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