The Yoshimura pattern — the Yoshimura pattern generator
yoshimura is one function. Everything below came out of it during this
build, at arguments taken from the essays rather than invented for this page — so a figure
here is the same figure a reader meets in an essay, and when the generator changes, this
page changes with it.
At its defaults
cols: 6, rows: 5
cols: 6, rows: 5, ratio: 1.9919
cols: 8, rows: 4, mm: 170
What it checked while it drew
Collected by running this generator with a listener on the assertions, not written here. The count is how many separate times this build put that claim to the test.
- developability holds at every interior vertex — its sectors close to 360° — 22 checked ×2
- Kawasaki holds at every interior vertex — the alternating sums of the sectors agree — 22 checked ×2
- Maekawa holds at every interior vertex — mountains and valleys differ by exactly two — 22 checked ×2
- the big-little-big lemma holds at every interior vertex — no strictly smallest sector is flanked by two creases of one assignment — 22 checked ×2
- the interior vertex carries sectors of 60, 60, 60, 60, 60, 60°, which close to 360° and alternate to zero at any proportion at all — so the row height is fixed by the big-little-big lemma rather than by Kawasaki, and the pattern is drawn at a proportion where nothing is yet forbidden ×2
- at a row height of 1.992 half-columns the sectors still close to 360° and still alternate to zero, and every one of the 22 interior vertices fails — on the big-little-big lemma alone, with developability, Kawasaki and Maekawa satisfied at all of them ×1
- the Yoshimura pattern is put past all four theorems before it is drawn ×1
Where it is called
Changing this generator changes every figure on this list, which is what makes the list worth publishing rather than keeping in a check script.
A corrugation agrees with itself
A Miura fold of forty-eight panels and a twist tessellation patch of forty-nine have almost exactly the same number of independent closed chains for their letters to contradict themselves round — thirty-five against thirty-six. Sixty-four per cent of the Miura's drawn letterings are consistent and thirteen per cent of the patch's. A Yoshimura at thirty-three chains manages ninety-three. The room to fail sets the scale; the construction decides where in it a pattern lands.
How much line is on the paper
A crease pattern is described by its creases: how many, at what angles, in what arrangement. What a folder spends is length. The Yoshimura this site prints has eighty-six creases and 2,380 millimetres of folding on a sheet seventeen centimetres across; the Miura has thirty-eight creases and 1,049, and the fold-and-cut triangle has six and 258 — and the two counts do not rank the eight printed patterns the same way.
Patterns nobody designed
Crush a thin cylinder and it folds into a diamond lattice. Nobody chose the pattern — it is the buckling mode with the lowest energy, and it satisfies the flat-folding theorems because it just folded.
The cylinder the pattern chooses
A Yoshimura pattern folds into a tube, and the tube's diameter is not a property of the paper. The course of diamonds has to go round exactly once, so the sheet's width is spent on the circumference the moment the columns are drawn — and what a larger sheet buys is a longer tube, never a fatter one.
The sheet has a thickness
Every crease pattern describes a surface with no thickness. Everything anybody builds has some, and getting it around a corner is the central problem of turning origami into hardware.
Every generator · The tessellations field · The patterns a reader can fold