[dbbljack]

great observation. this sculpture of a samurai folded from a single sheet of paper indeed is not "normal" oragami.

[srvmshr]

For people looking at more of the mathematical side of how origamis are shaped and built, I recommend a wonderful book by Robert Lang: "Twists, Tilings, and Tessellations: Mathematical Methods for Geometric Origami"

This really covers a lot of ground on computational origami.