i have tried to analyse few of the hip files which have trees (coniferous and deciduous) made using l systems..

although i understood quite a bit im still left puzzled with its rules..

i searched the help context and managed to get a bit of info on the same..

i.e it works on the principle which assumes a=b & b=ab
but i cant really get more of a breakthrough with only this..

if anyone has more info on the topic, pls help me out..

P.S: i had watched this movie named “the illusionist” ..i loved the story but what struck me after i saw houdini's L systems is that the Orange Tree sequence where the tree grows out of the seed, with leaves and oranges coming out of it; was probably done using houdini's LSystems..(i dunno ..just guessing)
AND IT LOOKED AMAZING!!

I've learned it with cmivfx training on l-system…It's quite interesting.
It explains how to do animation of growing plants. It looks really complex at first glance(and it is a bit) but it's worth it, and you get use to the system, it's not as hard as it may seem. www.cmivfx.com

But also just reading at the manual is a good start, it's well explained and you can end up do a bit more than a=b & b=ab if you take the time to read it carefully.

Wiki is also a good help:http://en.wikipedia.org/wiki/L-system [en.wikipedia.org]

Anyways, that's how I got deeper into the l-system.I'm far from being an expert but it helped me alot…hopeit can help you!

Cheers!

L-systems is simple once you understand the underlying concept. Everything else builds on top of it. There is a premise and then rules. And then there are the symbols which turn the turtle(this is what actually draws on the screen) like + (turn right) - (turn left) and () repositioning the turtle etc. As far as I can see there is just one alphabet which moves the turtle forward(F) - correct me if I am wrong. So F in the premise would draw a straight line. FFF would draw a line 3 units long and F+F+F in the premise would draw a triangle and F+F+F+F draws a square. Now rules can be used for two things like node rewriting (geometry replacement ) and edge rewriting (geometry appending) thats where additional variables can be used.

Node rewriting

Premise: F+F+F
Rule : F=F-F++F-F
This is a standard koch snow flake.

Edge rewriting

Premise:FX
Rule: X=-F++F-FX

What I have give here is 2D, but advanced operations allows the turtle to move in 3D and to branch and specify the lengths of each branches. Tree and planting modelling uses edge rewriting.

I am not sure if this will help at all, but when you design an L-System start at the point farthest from the origin.

IE: start with the twigs and leaves, then do the branches from which the twigs sprout. (might want to do a few branches for variety)
Now you have to do the larger branches and the trunk from which they spring.

Start small (most common) then work your way to the large (Most obvious)

Take note that it is also case sensitive.
F and f are different….“f” draws a line and “F” moves forward without drawing a line.

The Algorithmic Beauty of Plants has a free online version these days:
http://algorithmicbotany.org/papers/#webdocs [algorithmicbotany.org]

thanks a ton guys..the info is certainly very useful..
gonna check out some notes and tuts mentioned here..
cheers..

edward great link man….
thanks a ton
cheers