4 ms·Donuts are another option. That’s what you get when you join a square at each pair of opposite edges.by simonh 3y agoDonuts are another option. That’s what you get when you join a square at each pair of opposite edges.ithkuil 3y agoIndeed the gaussian curvature in a torus is 0.ithkuil 3y ago(in 4d only)