• x = a.cos(t) + b.cos(3.t)
• y = a.sin(t) - b.sin(3.t)
• z = c.sint(2.t)
• La sphère (balle) a son centre en <0,0,0> et son rayon d = a+b, et c = 2.√(a.b)

#declare deuxpi = 2*pi;
#declare r = 0.15;

#declare currentPt = <0.00, 0.00, 0.00>;
#declare previousPt = <0.00, 0.00, 0.00>;
#declare theColor = rgb <0.00, 0.00, 0.00>;

#declare a = 3;
#declare b = 2;
#declare c = 2*sqrt(a*b);

#declare i=0;
#declare step=pi/250;
#while (i < deuxpi)
	#set theColor = rgb CH2RGB(degrees(i));
	#set currentPt = < a*cos(i)+b*cos(3*i), a*sin(i)-b*sin(3*i), c*sin(2*i) >;
	sphere { currentPt, r pigment { theColor } finish { courbeFinish } }
	#if(i!=0)
		cylinder { previousPt, currentPt, r pigment { theColor }  finish { courbeFinish } }
	#end
	#set previousPt = currentPt;
	#set i=i+step;
#end

sphere {
	<0, 0, 0>, a+b 
	pigment { color White transmit 0.70 }
	finish { ambient 0.40 diffuse 0.60 brilliance 2 }
	}