Evolution of L-systems for compact virtual landscape generation

An L-system or Lindenmayer system consists of a grammar and an interpreter. The grammar contains an axiom, usually a short string, that the grammar expands into a long, complex string. The interpreter then renders the string into an object. A midpoint L-system is a generalization of L-systems to two-dimensional arrays of characters inspired by midpoint displacement fractals. This study presents a system for simultaneously evolving the rules and and interpreter for a midpoint L-system that encodes a desired landscape. Unlike a midpoint displacement fractal a midpoint L-system is deterministic and can be evolved to yield fixed, complex shapes. The fractal character of a midpoint L-system permits the storage of a large complex virtual landscape in a small data object. The level of detail rendered by an L-system can be changed rapidly and, with a fast graphics engine, dynamically. This study introduces midpoint L-systems, gives techniques for evolving them, and demonstrates those techniques on trial landscapes that resemble hills and craters. The application of this work is for virtual reality where midpoint L-systems will allow a designer to select from many rugged versions of a landscape without requiring vast amounts of storage or machine time to render them.