L-system-explorations

A repository tackeling the diverse visual outputs of L-Systems. Based on a introduction by Daniel Shiffmann and his book The Nature of Code

Basics

L-Systems are based on strings and are a way to apply a recursive function to a sentence.

Every L-System consists of:

• Alphabet: e.g. A B
• Axiom: Generation Zero Sentence, e.g. 'A'
• Ruleset:
  • 'A' => A B A
  • 'B' => B B B

         A

  A      B      A

A B A  B B B  A B A 

Code Approach

We are using a recursive function to create an always growing array of characters. Check code example NOC_8_08_SimpleLSystem

Gen1  [A]
Gen2  [A, B, A]
Gen3  [A, B, A, B, B, B, A, B, A]

In Processing we use a StringBuffer for this, it's very efficent and comes with an append() method.

### Drawing with L-Systems

Similar to the Turtle Drawing approach. A turtle can:

• 'F' => Draw a line (line(), translate())
• 'G' => Move fwd without drawing (translate())
• '+' => Turn right (at some angle) (rotate())
• '-' => Turn left (at some angle) (rotate())

But in order to be able to draw fractal patterns you also need to be able to save some positions:

• '[' => save state (position, direction) (pushMatrix())
• ']' => restore state (go there) (popMatrix())

Check code example NOC_8_09_LSystem

References

• Nature of Code, by Daniel Shiffman, L-Systems
• The Algorithmic Beauty of Plants, by Aristid Lindenmayer