Turing patterns: Holes

Two chemicals spread and react on a grid that wraps around, and spots, stripes or mazes grow on their own. Pick a preset, set how it grows, then download a seamless repeat.

Holes

Pattern
Growth

A finer grid fits more, smaller shapes in each repeat. More steps let the pattern settle; fewer show it still growing. A finer grid with more steps takes a second or two to draw.

Look

Where the edge is drawn, from the lowest level of the second chemical to its highest. Lower levels make fatter shapes.

Colors

The inner band color is used only by the two-band style.

More palettes
Printing

How it works

This is the Gray-Scott model. Chemical A is fed in everywhere, B turns A into more B, and B is slowly removed. Both spread to neighboring cells, A twice as fast as B. The feed and kill rates decide what grows: John Pearson mapped them in 1993, and each preset is a pair from a different region of his map. The grid's edges join up, so the pattern grows on the surface of a doughnut, and the repeat has no seam to hide.

Sources

  • John E. Pearson, Complex Patterns in a Simple System, Science 261, 1993. The feed and kill rates behind the Turing pattern presets come from the regions of this paper's map of the Gray-Scott model.
  • Karl Sims, Reaction-Diffusion Tutorial. The Turing pattern maker's simulation step: the diffusion rates, the 3 x 3 Laplacian, and the mitosis and coral rates.
Acknowledgements