i wanted to test the math i found at internet and draw a
and i try to render it by
KleinS.vertex(xs, ys, zs);
KleinS.vertex(xs+1, ys+1, zs+1);
and i got something what looks like i am close,
but not know if my math, my loops or my shape vertex are wrong.
if someone has a idea ( and want to take a look ) pls find