High!

stbenge wrote:

 >> ...to make use of more advanced raytracing techniques such as media 
- and may have to content myself for the rest of my life with beginner's 
scenes!
 >>
 >> I'm still not able to produce planetary rings through which light is 
scattered also to the unlit side... here is the code (no, it's just a 
test scene, not a real Saturn!), and below two scenes showing the lit 
and unlit side of the rings!
 >

 >
 > ...Here is some 3.6-compatible code you might find useful:
Perhaps... but I want to adopt it for my already existing Saturnian 

images) rather than just using a ready-made Saturn-like planet.
 > // begin code
 > global_settings{assumed_gamma 1.0}
 >
 > #default{finish{ambient 0}}
 >
 > camera{
 >  location<0,-1000,-10000>
 >  look_at 0
 >  angle .05
 >  sky<-.5,1,0> absorption 200/<1,.9,.8>
 > }
 >
 > light_source{<1,.05,0>*100000,<2.5,2.2,2>}
 >
 > sphere{0,2
 >  pigment{
 >   bumps scale<100,.5,100> turbulence .5
 >   color_map{[0 rgb 1][.5 rgb<.5,.4,.3>][1 rgb .5]}
 >  }
 >  hollow
 > }
 >
 > #declare ring_radius = 5.5;
 > cylinder{
 >  -y*.001,y*.001,ring_radius
 >  pigment{rgbt 1}
 >  interior{
 >   media{
 >    scattering{5,200*<1,.9,.8>}
 >    absorption 200/<1,.9,.8>

Your ring is 5.5 units wide, so I assumed that there is a 36.36 ratio 
between ring radius and scattering/absorption strength... but when I 
applied this to my test scene (not yet the real Saturn scene - for the 
time being, I'm somewhat reluctant to further mess up its already quite 
complicated code!) with a ring radius of 36,800 units, I only got a 
result quite similar the images posted at the top message of this thread!

Would your scattering/absorption settings also work with just a simple 
cylindrical pattern color map rather than your sophisticated function?

Here is my current version of the code:

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
       {
         scattering
         {
           5, 1338181 * <1, 0.9, 0.8>
           extinction 1
         }
         absorption 1338181 / <1, 0.9, 0.8>
         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

Post a reply to this message