import math;
import graph3;
import palette;

size3(8cm,8cm,IgnoreAspect);
size(8cm,0);

currentprojection=perspective(camera=(7.44,3.35,-1.67));

real a=1;
real f(pair z){
   real tempo=0.01-((z.x^2+z.y^2)^2-a^2*(z.x^2-z.y^2))^2;
   if(tempo>=0) return sqrt(tempo);
   else return 0;
   }

surface s=surface(f,(-1.1,-.5),(1.1,.5),100,100,monotonic);

draw(s,paleyellow,black,light=Viewport);