//--------------------------------------------------------------------------
// sky ---------------------------------------------------------------------
#local SkyTransform  = transform{ rotate <0,0,0> translate  <-3,0,-3> } 
//--------------------------------------------------------------------------
sky_sphere{ pigment{ gradient <0,1,0>
                     color_map{
                                [ 0.0 color rgb <0.24, 0.32, 1.0>*0.3 ]
                                [ 0.23 color rgb <0.16, 0.32, 0.9>*0.9 ]
                                [ 0.37 color rgb<1,0.1,0> ]
                                [ 0.52 color rgb<1,0.2,0> ]
                                [ 0.70 color rgb <0.36, 0.32, 1.0>*0.7 ]
                                [ 0.80 color rgb <0.14, 0.32, 1.0>*0.5 ]
                                [ 1.00 color rgb <0.24, 0.32, 1.0>*0.3 ]
                              } // end color_map
                     scale 2
                     rotate<-15,0,0>
                     translate <0,0.7,0>
                   } // end pigment
          } // end of sky_sphere ------------------------------------------
// white clouds:
plane{<0,1,0>,1 hollow  
       texture{ pigment{ bozo turbulence 0.92
                         color_map { [0.00 rgbt<1,1,1,1>] // <0.24, 0.32, 1.0>*0.7]
                                     [0.50 rgbt<1,1,1,1>] // <0.24, 0.32, 1.0>*0.7]
                                     [0.60 rgb <1,1,1>]
                                     [0.85 rgb <0.25,0.25,0.25>]
                                     [1.00 rgbt<0.5,0.5,0.5, 0.65>]}
                        scale<1,1,1.5>*3.5  translate< 0.5,0,0>
                       }
                finish {ambient 1 diffuse 0 }
                }      
       rotate<0, 0,0> transform SkyTransform
       scale 10000}
// red orange clouds:
plane{<0,1,0>,1 hollow  
       texture{ pigment{ bozo turbulence 0.92
                         color_map { [0.00 rgbt<1,1,1,1>] // <0.24, 0.32, 1.0>*0.7]
                                     [0.45 rgbt<1,1,1,1>] // <0.24, 0.32, 1.0>*0.7]
                                     [0.75 rgbt <1.00,0.15,0.00,0.50>]
                                     [0.85 rgbt <0.75,0.55,0.00,0.30>]
                                     [1.00 rgbt <0.50,0.35,0.15, 0.75>]}
                        scale<1,1,1.5>*3.5  translate< 0.5,0,1.5>// +move it in z
                       }
                finish {ambient 1 diffuse 0 }
                }      
       rotate<0, 0,0>  transform SkyTransform
       scale 9900}
//-------------------------------------------------------// end sky + clouds
// fog on the ground -------------------------------------------------------
fog { fog_type   2
      distance   50
      color      rgb<1,0.35,0.1>  
      fog_offset 0.1
      fog_alt    1.0
      turbulence 1.8
    } //------------------------------------------------// end of ground fog
//--------------------------------------------------------------------------