L-systems, or Lindenmayer systems, are a way of simulating bacteria, plant, and fractal growth. This is done using recursive string rewriting and a way to render strings to a 2D or 3D space, which can be used to create multiple general rulesets.
Recursive string rewriting is used in L-systems to generate the "growth" of the preferred organism. This is done using a set of rules that are applied to modify a given string recursively. Consider the following L-system:
F -> F, F+F-F-F+F, F-F+F+F-F, FF+[+F-F-F]-[-F+F+F], F[+F]F[-F]F, FF-[-F+F+F]+[+F-F-F]This ruleset is used to generate a plant-like structure in 2D space. Note how this is done on the whole string, and not just the end portion of the string.
This system was built in a string format with this code:
function l_system(current, rules, generations) {
let next = '';
for (let i = 0; i < generations; i++) {
for (let j = 0; j < current.length; j++) {
let c = current[j]
if (rules[c]) {
next += random(rules[c])
} else {
next += c
}
}
current = next
next = ''
}
return current
}