//A Type 2 Steiner surface
//by Adam Coffman

camera{location <-7.3,0,5.2>
       look_at  <0,0, 0> }          
       
background{color<0,0.5,0>}            
 
quartic{ <
  0, 0, 0, 0, 0, 0, 0, -1, 0, 1, 0, 0, 0, 0, -1, 
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
  0, 0, 1, 0, 0>
   sturm 
   texture {
        pigment{
           radial frequency 52
           color_map{[0.0 color<0,0,0>][1.0 color<1,1,1>]}
          }
        finish {
         phong 1.0
         phong_size 10
         ambient 0.6
         diffuse 0.4
         reflection 0.2   
      } 
   }             
   bounded_by { cylinder{<0,-4,0><0,4,0>,3}  } 
   clipped_by { bounded_by }
   rotate x*90   
   rotate z*-30
   }                       
  
light_source{<-40,4,4>,color<1,1,1>}
light_source{<0,40,40>,color<1,1,1>}
light_source{<10,40,4>,color<1,1,1>}