%http://xahlee.org/surface/klein_bottle/klein_bottle.html input mp-solid invnormale:=-1; %19'' figureespace(-10u,-10u,10u,10u); Initialisation(1500,0,30,45); incolor:=gris; arcenciel:=true; draw Sparam("((3+cos(v/2)*sin(u)-sin(v/2)*sin(2*u))*cos(v),(3+cos(v/2)*sin(u)-sin(v/2)*sin(2*u))*sin(v),sin(v/2)*sin(u)+cos(v/2)*sin(2*u))",0,2*pi,0.12566,0,2*pi,0.12566); finespace; end