%k3dsurf Kuen

input mp-solid

%6''
figureespace(-10u,-10u,10u,10u);
Initialisation(1000,-40,10,70);
incolor:=gris;
arcenciel:=true;
draw Sparam("((2*(cos(u)+u*sin(u))*sin(v))/(1+(u**2)*(sin(v)**2)),(2*(sin(u)-u*cos(u))*sin(v))/(1+(u**2)*(sin(v)**2)),ln(tan(0.5*v))+(2*cos(v))/(1+(u**2)*(sin(v)**2)))",2*pi,0.2513,-0.2513,0.01,3,0.04);
finespace;
end