"PLANTSIM - From Grammars to Geometry"
Mitch Haile 2002
Abstract
The complexion of plants is an examined and documented facet of science, just as other mysteries of nature, such as the arrangement of the night sky. PlantSim, as the name implies, is a study examining simulation techniques of plant models and plant ecosystems. Aristad Lindenmayer created a system to express plant structure using Noam Chomsky's work on formal grammars. Lindenmayer's "L-Systems" provide a means to communicate explicit definitions of plant structure at a given point in time. PlantSim extends Lindenmayer's model by adding named attributes and implementing a simple programming language, PlantCode, to control these attributes based on branching structure. The applications developed for this study include a GUI tool to generate user defined attributed plant grammars using Plantcode and an OpenGL visualization of the resulting plant grammar. Advanced geometric techniques are employed in the visualization, namely, quaternions for interpolated rotations and slerp (spherical linear interpolation). Screen shots are taken from the author's application.
A model created using the simple L-system definition. This model was grown for 7 steps, and contains 3,757 segments after compression.
These two images were grown from the same grammar for the same period of time (iterations). Yet, due to a simple probability distribution, the two models have a different number of segments, a different total expansion length, and a visibly different geometric structure.