Patterns dynamic formation
The Particles use the same scheme of interaction (broadcast of events). The reception part of the program of a Particle is made of two parallel blocks. This part corresponds to a complex potential treatment. The first block models the repulsive part of potential (repulsion on small distances, proportional to exp(-r)) and the second one uses the standard 1/r potential to model its attractive part. This is a "thin-films-formation"-like approach where the resulting structure is defined by the minimum of energy. We add an Air object to reduce the action of the inertial behavior and to make the process more "stable".
By reseting the simulation one can observe different pattern formation strategies. Once a stable configuration is reached, you can supress the Air object by deleting the associated icon. Try also to delete some particles in the center of a stable configuration to observe a new dynamic pattern formation.