imclab / lsys.js

3D L-Systems JavaScript Implementation

L-Systems.JS

A complete, 3D L-Systems implementation in JavaScript. Generates trees by production rules and draws by converting to cartesian coordinates.

Usage

var lsys = new LSystem('F', { 'F' : 'F-F+FF' }).iterate(2);
var tree = lsys.print();
console.log(tree);  // F-F+FF-F-F+FF+F-F+FFF-F+FF
var coords = lsys.draw(Math.PI / 2);  // draw tree with alpha as 90 degrees
console.log(coords);  // [[0,0,0], [0,1,0], [1,1,0], ...

Definition

An L-system is a formal grammar defined as an initial axiom string, and a set of production rules. In the aforementioned example, F is the initial axiom, and only one production rule exists: F -> F-F+FF. The grammar alphabet is assumed to be all characters with a production rule mapping.

Syntax

• F: draw and move one unit vector forward
• +/-: turn right / left
• &/^: pitch up / down
• </>: roll right / left
• |: reverse vector direction
• [/]: push / pop current tree state

More

For more info and examples, check out http://yuvadm.github.com/lsys.js