Trees Growing Branches

Branches rise up and travel on sine wave modified lines. You control the thickness and curviness of the trees.

It’s Interactive: Click to make new trees. Clicking towards the top of the screen makes for straighter branches, towards the bottom for curvy ones. Clicking towards the left makes skinny branches, right makes fat ones.

Requires HTML5 Support (Firefox, Chrome or Safari) to see in the browser. If you are using an unsupported browser, try the java version over at openprocessing.com.

Source Code Below.

// most basic branching test:
// Draw a straight line for a little while
// If chance of branching is exceeded, then add another branch
int i=0;
int totalBranches=10000;
int numTrunks=10;
float  dimX=521,dimY=452;
float branchOdds=.02;
float moveDistance=2;
int trunkWidth=20;
tree[] trees;
int branchesSoFar=-1;
float newBranchSpinAgleMax=PI;
float minAngle=PI*.0015,maxAngle=PI*1.1;

void setup(){
  size(int(dimX),int(dimY));
  trees = new tree[totalBranches];
  background(255,255,255);
  for(i=0;i<numTrunks;i++){
    trees[i] = new tree(random(dimX),dimY,branchOdds,trunkWidth,moveDistance,minAngle,maxAngle,#000000,0);
    branchesSoFar++;
  }
  smooth();

}

void draw(){

    for(i=0;i<branchesSoFar;i++){
     // print(i);
    trees[i].draw();
  }
    fill(255,5);
   // rect(0,0,dimX,dimY);
}
int randomSign(){ //returns +1 or -1
  float num = random(1);
  if(num<.5)
    return -1;
  else
    return 1;
}

void mousePressed(){
  branchesSoFar=0;
  fill(255);
  rect(0,0,dimX,dimY);

  for(i=0;i<numTrunks;i++){
    trees[i] = new tree(random(dimX),dimY,branchOdds,mouseX/20,moveDistance,minAngle*mouseY/50,maxAngle,#000000,0);
    branchesSoFar++;
  }

}

class tree{
  int bWidth;
  float x1,x2,y1,y2=0;
  float bOdds;
  float mDistance;
  color bColor;
  float bSeg;
  int bGeneration;
  float mnAngle,mxAngle;
  float currentAngle=PI;

  tree(float sx, float sy, float branchOdds, int branchWidth, float moveDistance, float minAngle, float maxAngle, color branchColor, int branchGeneration){
    bWidth=branchWidth;
    x1=sx;
    y1=sy;
    y2=y1;
    x2=x1;
    bOdds=branchOdds;
    mDistance=moveDistance;
    bColor=branchColor;
    bSeg=0;
    bGeneration=branchGeneration;
    mnAngle=minAngle;
    mxAngle=random(minAngle) * randomSign();
}

  void draw(){
    if (x1>0 && y1>0){

      strokeWeight(bWidth);
      if (bWidth>=1) {
        // Draw next segment 10 paces up.
        currentAngle+=mxAngle;
        //print ('\n'+currentAngle+" ");
        x2=x2 + sin(currentAngle)*moveDistance;
        y2=y2 + cos(currentAngle)*moveDistance;;
        stroke(bColor);
        line(x1,y1,x2,y2);
        x1=x2;
        y1=y2;
        if (random(1)<bOdds){
          branchesSoFar++;
          //print("added");
          color newColor=color(10*bGeneration,10*bGeneration,10*bGeneration,155);
          int newWidth=int(trunkWidth-bGeneration*2);
          float newAngle=mnAngle*1.35;
          trees[branchesSoFar] = new tree(x2,y2,bOdds,bWidth,moveDistance,newAngle,maxAngle,newColor,bGeneration+1);
        }
        bSeg++;
        if (bSeg/10==int(bSeg/10)){
          bWidth--;
        }
      }
    }
  }
}

Posted: December 3rd, 2009 | Author: Rob | Filed under: Animation, Processing, Programming | 4 Comments »

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