On a 9 by 9 grid, draw 20 nodes. Each node is drawn with a circle, and a series of lines that converge to a center point. For all of the points, draw a branching network starting from the node closest to the center. For each node, connect the nearest other node with a line.
This sketch uses the branching network algorithm explained in Algorithmic landscapes : computational methods for the mediation of form, information, and performance in landscape architecture (Claghorn, 187)
Very much inspired by Matt DesLauriers