orthogonality with it's neighbors,

distance to it's neighbors,

and nearness or contact with a boundary.

Common grid generation algorithms require the location of all boundary nodes to solve for the locations nodes interior to the domain. A cellular automata approach only requires the upstream and downstream node locations to be fixed on the appropriate boundaries.

GGGG's Great Grid Generator (4G) is the beginning of a complete, cellular automata, grid generation system. It is platform independent software, written in Python with the Numerical Python extension. 4G is released under the GNU General Public License and is available at http://sourceforge.net/projects/gggg.

Check out the numerical rocket simulation, or the compound angle calculator.