L-System fractals

Click a picture to show (hide) fractal rules.
More examples from Fractint: animated Dragon, famous curves (carpets :) and trees.

How to raise a "tree"

I've found tiny Jim Graham's L-System applet in JDK demo. Fractal parameters are set in a HTML page. A CLSFractal.java "Turtle" uses next orders:
F - to go forward one step, drawing a line,
f - to go forward one step, not drawing a line (jump),
[ - to branch off, saving its current position for later movement,
] - to restore the position it had prior to the branch,
+ - a clockwise (right) rotation,
- - a counter clockwise (left) rotation on rotangle.

L-System fractal begins from string-axiom (for example):
axiom: F
then it makes substring substitution (rules) pred -> succ, for example:
pred=F
succ=F[-FF]F[+FF]F

you may use a few rules. The process be repeated level=N times. Then the string is used as a "turtle" path.

HTML text is

<applet code="CLSFractal.class" width=250 height=250>
<param name=level value="4">
<param name=axiom value="F">
<param name=pred1 value="F">
<param name=succ1 value="F[-FF]F[+FF]F">
<param name=rotangle value="25">
<param name=startangle value="-45">
</applet>
This is the step by step iterations

and the final result

How do they grow ("Dragon at Tree at al." interactive ILSFractal).


E-notes     updated 1 July 99