One inputθ is the only variable. Every dihedral angle in the sheet is a consequence — the surface has exactly one way to move. Press and hold the sheet to hurry the fold.
Rigid origami · one parameter
Divide a plane into parallelograms and skew every other row. The crease pattern that results — straight folds one way, herringbone zigzags the other — has a single degree of freedom: set the fold angle θ and every facet's position follows by necessity. Nothing bends, nothing stretches, nothing tears. The sheet above recomputes all of its facet planes from θ alone, sixty times a second.
01 / Tokyo, 1970
Kōryō Miura wanted a chart you could open one-handed. Fold it his way and the sheet never fights itself: pull two opposite corners and the whole plane deploys in one motion, refolds in one motion, and never creases wrong.
02 / Orbit, 1995
Japan's Space Flyer Unit deployed its solar array on this exact fold. No motors down the panel line, no hinge to seize in vacuum — one actuator drives the single degree of freedom and the array unfurls flat.
03 / The mathematics
Each facet stays a rigid parallelogram through the entire fold — edge lengths constant to the last decimal. Watch the crease lines: vermilion ridges and dark valleys deepen as the packet gathers, fade as the sheet relaxes flat.