ofxLSystem

This addon has a dependency on ofxLSystemGrammar. Download it and add it to your addon folder

ofxLSystem is a 3D graphic turtle graphic interpretation of L-Syestems. In the readme of ofxLSystemGrammar you can find some information about L-System. This addon can be used to generate meshes as the following ones:

Supported platforms

It is currently tested on mac, linux and windows and the current version of openFrameworks in master

On linux, you need g++ > 4.9 and the -std=gnu++14 flag. Otherwise you will have an error about std::regex_iterator. This flag is the default since OF 0.9.3, just in case you set it to std=c++11 as described in this post.

Usage

In your header file include ofxLSystem and declare an instance of it. Declare also a material, it will be applied to the tree's mesh.

#include "ofxLSystem.h"
// ...
ofxLSystem tree
ofMaterial treeMaterial

In your ofApp.cpp

void ofApp::setup(){
  treeMaterial.setDiffuseColor(ofFloatColor::blueSteel)
  tree.setStep(4);
  tree.build();
}


void ofApp::draw(){
  treeMaterial.begin();
  tree.draw();
  treeMaterial.end();
}

tree.setAxiom("F") tells to ofxLSystem to use F as axiom, tree.setRules({"F -> FF[+F][-F]"}) to use F -> FF[+F][-F] as reproduction rule and tree.setStep(4) to iterate 4 times. Have a look into ofxLSystemGrammar or in the 2 examples in this project for more L-System examples.

By default, each L-System is initialized with this parameters:

typedef map<string,float> Constants;

vector<string>    rulesContainer = {"F -> F[+F][-F]"};
string            axiom = "F";
bool              randomYRotation = false;
int               depth = 1;
float             theta = 25.00;
float             stepWidth = 10.00;
bool              scaleWidth = false;
float             stepLength = 100.00;
map<string,float> constants = Constants();

you can overwrite the default parameters using these methods:

void setAxiom(string _axiom);
void setRules(vector<string> _rulesContainer);
void setTheta(float _theta);
void setRandomZRotation(bool _randomYRotation);
void setStep(int _depth);
void setScaleWidth(bool _scaleWidht);
void setStepWidth(float _stepWidth);
void setStepLength(float _stepLength);
void setConstants(map<string,float> _Constants);

For example, the following snippet:

ofxLSystem tree;
map<string, float> constants;
constants.insert(make_pair("R", 1.456));

tree.setAxiom("A(100)");
tree.setRules({"A(s) -> F(s)[+A(s/R)][-A(s/R)]"});
tree.setRandomYRotation(true);
tree.setConstants(constants);
tree.setStep(4);
tree.setScaleWidth(true);
tree.setStepLength(90);

Generates a tree like this:

Examples

• example-gui contains ~10 differents L-Systems, with a GUI to change colors, rotation angle, n steps ecc. It saves the settings for each tree on a separate xml file
• example-forest An example on how you can build a forest merging the meshes of 60 trees in one
• example-shader I've added some simple shaders following "the book of shader" of Patricio Gonzalo Vivo.