/*Conoïde de Plücker

 équation : z*(x^2+y^2)-x*y = 0 */

#include "colors.inc" 
#declare a=10;
#declare b=-2;  

camera { location <0.5,0,-5>*0.7 look_at<0.1,-0.3,0> }
light_source { <-10,18,-20>*15 color White*0.99 } 
light_source { <50,-10,-10> color rgb <1,0.6,0>*0.6 }

sky_sphere {
    pigment {
      gradient y
      color_map {
        [ 0.35  color rgb<0.4,0.8,1> ]
        [ 0.6  color  rgb<0.2,0.4,0.8> ]
                }
      scale 2
      translate -1
    }
  }

union {  
poly{ 3,<0,0,1.,0,0,0,-1.,0,0,0,0,1.,0,0,0,0,0,0,0,0.>
     pigment {   rgb <0.8,.55,.1>*1.1  }  
     finish { specular .7 roughness 0.01 ambient 0.6  reflection 0.05}     
    } // fin poly
    
    cylinder{ <-(a+sqrt(a*a-1)),-1,1/2/a>,<a+sqrt(a*a-1),1,1/2/a>,0.008
         pigment{ Cyan}
         } // fin cylindre1 
          
    cylinder{ <-(b+sqrt(b*b-1)),-1,1/2/b>,<b+sqrt(b*b-1),1,1/2/b>,0.008
         pigment{ Cyan}
         pigment{ Cyan}                      
         } // fin cylindre2
         
    clipped_by { cylinder{ <0,0,-2>,<0,0,2>,1 }}
    bounded_by { clipped_by } 
    scale 1.8
    rotate <80,0,-10> 
}
           
plane{ y,-5 
      clipped_by { box{ <-200,-5.5,-5>,<200,-4,50>  }} 
      texture { pigment{rgb<0,1,0.6>*0.4}
       			normal{ bumps 3.5 noise_generator 3} 
       			scale <1,100,1>*0.01 
       			finish {ambient 0.8 diffuse 0.5   roughness 0.01 } 
             }    
       rotate <0,-6,0>
      }