video: hyphae algorithm diagram
We start with a set of randomly, but evenly distributed “auxin sources”, this kind of distribution is called “blue noise.” We add one or more root veins. The growth proceeds by each source influencing its neighbor veins. Each vein then grows toward the average influence of the sources. And this repeats. A source can effect multiple veins at once, as long as they are relative neighbors, aka coming from sufficiently different directions. This allows for the formation of closed cells. Sources die when a vein comes too close to them.