Klein bottle



Here is an other implementation of Klein bottle as seen on the front of a book seen to the right. I started with a triangle r(t) = [ Cos[t] + Cos[2 t]/2, Sin[t] - Sin[2 t]/2, 0 ] and then drew circles around it where the radius r depends on the position. r = 0.2 + Cos[3 t/2]^2.