cpart renders a fixed lattice of points whose orientations affect their brightness and their neighbors. Each point has a preferred direction. Local interactions pull it away from that direction, producing changing patterns across the field.
Interaction
The camera can orbit and zoom. Controls adjust restoration, coupling, pressure, damping, and the brightness response. Several initial direction patterns make it possible to inspect the same rules under different starting conditions.
A moving probe perturbs nearby particles. It can follow an automatic path or be steered through the field, leaving visible changes in orientation.
This is a simulation and visualization experiment with explicit, adjustable rules. Its terminology describes those rules, rather than a model of a known physical medium. The useful questions are how local interactions sustain or suppress patterns and which changes are visible when one parameter is varied.