Hello, I'm trying to make a boids system with obstacles in processing. I made the system but can not make the boids react on obstacle: 1. To group around obstacle permanently 2. To make my boids pass round the obstacle. I attached text file with my code. Could somebody help me, please, seems that I'm completely lost here. Thank you,

Evgeniya 
             

              
import toxi.geom.*; import controlP5.*; //DECLARE ControlP5 jControl; ArrayList ballCollection; int bColor=0; int lineBetween=10; int separate=10; int cohesion=10; int sEllipse=10; int eMove=1; int align=200; void setup() { size(600,600); smooth(); ballCollection = new ArrayList(); jControl=new ControlP5(this); Slider b = jControl.addSlider("bColor", 0,255,0,10,10,200,10); Slider l = jControl.addSlider("lineBetween", 0,80,10,10,25,200,10); Slider s = jControl.addSlider("separate", 0,80,10,10,40,200,10); Slider c = jControl.addSlider("cohesion", 0,100,10,10,55,200,10); Slider e = jControl.addSlider("sEllipse", 0,15,10,10,70,200,10); Slider m = jControl.addSlider("eMove", 0,7,1,10,85,200,10); Slider a = jControl.addSlider("align", 0,400,100,10,100,200,10); for(int i = 0; i < 100; i++) { Vec3D origin = new Vec3D(random(width),random(200),0); Ball myBall = new Ball(origin); ballCollection.add(myBall); } } void draw() { background(bColor); fill(255,10); fill(255); ellipse (width/3,height/4, 15,15); ellipse (width/2,height/1.5, 15,15); for(int i = 0; i < ballCollection.size(); i++) { Ball mb = (Ball) ballCollection.get(i); mb.run(); } if(keyPressed) saveFrame("agent_###.jpg"); } void mousePressed() { Vec3D origin = new Vec3D(mouseX,mouseY,0); Ball myBall = new Ball(origin); ballCollection.add(myBall); } class Ball { Vec3D loc = new Vec3D (0,0,0); Vec3D speed = new Vec3D(random(-10,10),random(-10,10),0); Vec3D acc=new Vec3D(); Vec3D grav = new Vec3D(0,0.2,0); float r; Ball(Vec3D _loc) { loc = _loc; r = 0.1; } void run() { display(); move(); // bounce(); // gravity(); borders(); lineBetween(); flock(); } void flock() { separate(4); cohesion(0.001); align(0.1); } void align (float magnitude) { Vec3D steer =new Vec3D(); int count=0; for (int i=0; i<ballCollection.size(); i++) { Ball other=(Ball) ballCollection.get(i); float distance=loc.distanceTo(other.loc); if (distance>0&&distance>align) { steer.addSelf(other.speed); count++; } } if (count>0) { steer.scaleSelf(1.0/count); } steer.scaleSelf (magnitude); acc.addSelf (steer); } void cohesion(float magnitude) { Vec3D sum =new Vec3D(); int count=0; for (int i=0; i<ballCollection.size(); i++) { Ball other=(Ball) ballCollection.get(i); float distance=loc.distanceTo(other.loc); if (distance>0&&distance<cohesion) { sum.addSelf(other.loc); count++; } } if (count>0) { sum.scaleSelf(1.0/count); } Vec3D steer=sum.sub (loc); steer.scaleSelf(magnitude); acc.addSelf(steer); } void separate(float magnitude) { Vec3D steer=new Vec3D(); int count=0; for (int i=0; i<ballCollection.size(); i++) { Ball other=(Ball) ballCollection.get(i); float distance=loc.distanceTo(other.loc); if (distance>0&&distance<separate) { Vec3D diff=loc.sub (other.loc); diff.normalizeTo (1.0/distance); steer.addSelf(diff); count++; } } if(count>0) { steer.scaleSelf(1.0/count); } steer.scaleSelf(magnitude); acc.addSelf(steer); } void lineBetween() { //ballCollection for (int i=0; i<ballCollection.size(); i++) { Ball other=(Ball) ballCollection.get(i); float distance=loc.distanceTo(other.loc); if (distance>0&&distance<lineBetween) { stroke (255,0,0); strokeWeight (0.1); line(loc.x,loc.y,other.loc.x,other.loc.y); } } } void gravity() { speed.addSelf(grav); } void bounce() { if(loc.x > width) { speed.x = speed.x * -1; } if(loc.x< 0) { speed.x = speed.x * -1; } if(loc.y > height) { speed.y = speed.y * -1; } if(loc.y < 0) { speed.y = speed.y * -1; } } void borders() { if (loc.x < -r) loc.x = width+r; if (loc.y < -r) loc.y = height+r; if (loc.x > width+r) loc.x = -r; if (loc.y > height+r) loc.y = -r; } void move() { speed.addSelf(acc); speed.limit(eMove); loc.addSelf(speed); acc.clear(); } void display() { strokeWeight(0.01); stroke (255,0,0); fill(157); ellipse(loc.x,loc.y,sEllipse,sEllipse); // fill(157); // triangle(loc.x,loc.y,loc.x+2,loc.y+10,loc.x-2,loc.y+10); } }