//F. Apery's homotopy from
//Steiner's Roman Surface
//to Boy's Surface
//by Adam Coffman

camera {
    location  <-2.75, 2.1,-0.27>
    look_at   <0.03, 1.2, 0.05>
      }
#include "colors.inc"  
#declare s = sqrt(2);
#declare T = (1-cos(2*pi*clock))/2;
background{White}           
poly{ 6, < -81*T*T, 0, 108*s*T*T, 0, -243*T*T, 162*s*T*(1-T*T), 0,
-18-72*T*T, 36*T*T, 0, 0, -216*s*T*T, 0, 0, 0, 0, -24*s, 24*s*(1-T*T),
0, 0, -243*T*T, 108*s*T*(1-T*T), 0, -36-144*T*T, 72*T*T, 0,
s*T*(108+36*T*T), -144*s*T, 0, 0, 36*T*T, 24*(1-T*T), -16, 0, 0, 0,
-324*s*T*T, 0, 0, 0, 0, 72*s, 72*s*(T*T-1), 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, -81*T*T, 54*s*T*(T*T-1), 0, -18-72*T*T, 36*T*T, 0,
-s*T*(36+12*T*T), 48*s*T, 0, 0, 36*T*T, 24*(1-T*T), -16, 0, 0, 0, 0,
0, 0, 0, 0, -24, 48, -32, 64/9, 0, 0, 0 >
     sturm
     pigment { SkyBlue }  
     finish {
         ambient 0.7
         phong 1
         phong_size 80                 
            }
     rotate x*-90      
    }             
plane { <0,1,0>, 0.02
        pigment{White}
        finish{ambient 1}
      }                  
light_source{<0.5,20,2> White shadowless} 
light_source{<-40,0.3,1.02> White}