Diffusion Limited Aggregation (DLA) has usually been studied in 2 dimensions as a model of fractal growth processes such as river networks, plant branching, frost on glass, electro-deposition, lightning, mineral deposits, and coral. Here the basic principles are extended into 3 dimensions and used to create, among other things, believable models of root systems. An additional innovation is a means of constraining the growth of the 3 dimensional DLA by a surface or containing it within a vessel. DLA in 3 dimensions The rules for forming DLA structures are very simple and were first introduced in 2 dimensions by T.A. Witten and L.M. Sander around 1981 [1]. A particle is introduced into an environment at a random position, it moves around randomly (for example: Brownian motion) until it encounters the existing structure (initially just a single stationary particle) at which stage it permanently adheres at the point of contact and becomes part of the DLA structure. As an example of DLA in...
Paul D. Bourke