It is possible to alter the parameters of the cyclic cellular automaton. Obviously, the number of states N per cell can be varied. But it is also possible to change the “threshold”, defined as the number of neighbours with value n + 1 (mod N) needed for a cell to advance from n to n + 1 (mod N). Some of these variants have specific names, and two particularly neat ones are “313” (three states, threshold 3) and “Perfect” (four states, threshold 3), shown below.

The “313” rule creates a pattern of “moustaches”:

The “Perfect” rule creates octagonal spirals:

Tomorrow I will make a different kind of adjustment to the cyclic CA.