Awesome. But. I didn't like the part where a 3D surface with linear interpolation was turned into a 2-D quadratic by placing 2 control points on top of each oth

Awesome. But. I didn't like the part where a 3D surface with linear interpolation was turned into a 2-D quadratic by placing 2 control points on top of each other. Yes, the interpolation formula becomes the same as a 2nd order Bezier, but I'm not sure the folding of the 3d surface like that was necessary. I though the author was going to show something new that I hadn't seen before, but soon ended up using the repeated-interpolation to describe higher order curve. That one part seems like a distraction to me.