#Processing script to simulate the patterns on Oliva Porphyria

This program simulates the color patterns on tropical sea shells, here 'Oliva porphyria'.

An autocatalytic activator a(i) leads to a burst-like activation that is regulated back by the action of an inhibitor b(i). The life time of the inhibitor is regulated via a hormone c, that is homogeneously distributed along the growing edge. Whenever the number of activated cells become too small, active cells remain activated until backwards waves are triggered.

You can run this script by opening it in the latest version of the Processing IDE (v3 at the time of writing) and using the 'Run' command.

This Processing script was written by Sarah Spencer 2017, http://heartofpluto.co/ and is based on the short version of a Visual Basic program written by H.Meinhardt and made publicly available here:

http://www.eb.tuebingen.mpg.de/research/emeriti/hans-meinhardt/shell-program.html

see also: Meinhardt,H. and Klingler,M. (1987) J. theor. Biol 126, 63-69

see also: H.Meinhardt: "Algorithmic beauty of sea shells"