Tool · Playground

L-system editor

Build your own Lindenmayer system. Write an axiom, write rewrite rules (deterministic or stochastic), set the turtle angle and recursion depth, and render. Branching ([ ]) and a random seed for stochastic rules are first-class.

Presets:

string length = 1,792 chars

Grammar

AxiomRules (one per line: F = F+F-F; stochastic: F = 0.5 F+F | 0.5 F-F)

Turtle

Angle = 60°Initial heading = 0° (0 = east, 90 = north)Depth = 4Seed (for stochastic rules) = 1

Vary colour

Turtle commands

F / G — forward + draw
f — forward, no draw
+ / - — turn left / right by angle
[ / ] — push / pop turtle state (branches)
Any other letter — used as a state symbol, drawn as no-op

Tips

Deterministic vs stochastic: write one RHS per symbol for classic L-systems; pipe-separated weighted RHSs (0.5 X | 0.5 Y) for stochastic ones, which model natural variation in plants.
Branching grammars need [ and ]. Without branches you can only draw curves, not plants. Push state, draw a sub-branch, pop back to where you were.
Watch the string length. Most L-systems grow exponentially. Crank depth carefully — the renderer caps at ~5M chars and the screen usually saturates well before that.
Read Prusinkiewicz & Lindenmayer's The Algorithmic Beauty of Plants for the full toolkit (parametric, contextual, and stochastic L-systems). The basics are all here.

The preset-only viewer lives at /tools/lsystems, and the reference page at /fractals/lsystems.

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