I tried to create some random points inside a boundary defined by color (RGB(100,100,100)). If each new point's relating pixel is RGB(100,100,100), then create the point; vice versa. However, I find it really hard to work with this array. anybody has an suggestion?

PImage b;
PImage c;

float envSize = 280;
int population = 1000;

color[] imgPixels = new color[parseInt(envSize*2)*parseInt(envSize)];
kVec strPt;

//setup
void setup() {
  smooth();
  b = loadImage("background.gif");
  size(b.width,b.height,P3D);

  c = loadImage("boundary.png");
  image(c,-width/2,-height/2);

  loadPixels();
  for(int i = 0; i < envSize*2*envSize; i++){
    imgPixels[i] = pixels[i];
  }

  for(int i = 0; i < population; i++) {

    strPt = new kVec(random(0,envSize),random(0,envSize/2),random(0,envSize/3));
    colorMode(RGB);
    if(pixels[parseInt(strPt.y)* width + parseInt(strPt.x)] == color(100,100,100)){
      //create the point here;
    }
  }

}

1. import processing.opengl.*;
   import peasy.*;
   import joons.*; 
2. PrintWriter output;
   ControlP5 controlP5;
   PMatrix3D currCameraMatrix;
   PGraphics3D g3;
   PeasyCam cam;
   JoonsRenderer jr;
3. float strWeight = 1;
   float Optdist = 5;
4. float eyeX = 600;
   float eyeY = 620;
   float eyeZ = 300;
   float centerX = 0;
   float centerY = 0;
   float centerZ = 0;
   float upX = 0;
   float upY = 0;
   float upZ = -1;
   float fov = PI / 3; 
   float aspect = (float) 1;  
   float zNear = 5;
   float zFar = 10000;
5. ArrayList points;
   boolean rendered = false; 
6. 
   void setup() {
     size(800,800,P3D);
7.   jr = new JoonsRenderer(this,width,height); //just declare like this.  
     jr.setRenderSpeed(0.5);
8.   //smooth();
     //background(0);
     //strokeWeight(0.7);
     controlP5 = new ControlP5(this);
     control();
     g3 = (PGraphics3D)g;
     //cam = new PeasyCam(this,600);
     cam = new PeasyCam(this, width-200);
     controlP5.setAutoDraw(false);
9.   points = new ArrayList();
10.   String[] cir_points;
      float x,y,z;
      float magnatude;
      cir_points= loadStrings("trails.txt");
11.   for(int index = 0; index < cir_points.length; index++) {
        String[] pieces = split(cir_points[index], ',');
        if (pieces.length == 4) {
          x = float(pieces[0]);
          y = float(pieces[1]);
          z = float(pieces[2]);
          magnatude = float(pieces[3]);
          points.add(new kPoint(new PVector(x,y,z), magnatude));
        }
      }
12. }
13. 
    void draw() {
      //background(0);
      //fill(255);
14.   beginRecord("joons.OBJWriter","");
      perspective(fov, aspect, zNear, zFar);
      camera(eyeX, eyeY, eyeZ, centerX, centerY, centerZ, upX, upY, upZ);
      for(int i = 0; i < points.size(); i++) {
        kPoint p = (kPoint) points.get(i);
        p.render();
      }
      translate(0,0,-400);
      box(200);
      translate(0,100,0);
      sphere(100);
      //floor plate
15.   rect(-2000, -2000, 5000, 5000);
      noSmooth();
      endRecord();
16.   gui();
17. 
      if(rendered)    
        jr.display();
    }
18. void gui() {
      currCameraMatrix = new PMatrix3D(g3.camera);
      camera();
      controlP5.draw();
      g3.camera = currCameraMatrix;
    }
20. import controlP5.*;
21. void control(){ 
      //strokeWeight
      controlP5.addBang("strokeWeight",0,40,80,20).setId(1);
      controlP5.controller("strokeWeight").setLabel("strokeWeight");
      //strWeight_slider
      controlP5.addSlider("strWeight",0,10,1,100,40,100,10).setId(2);
      controlP5.controller("strWeight").setLabel("strWeight");
22.   //optinum
      controlP5.addBang("optinum",0,80,80,20).setId(3);
      controlP5.controller("optinum").setLabel("optinum");
      //strWeight_slider
      controlP5.addSlider("dist",0,10,1,100,80,100,10).setId(4);
      controlP5.controller("dist").setLabel("dist");
23.   //tabs
      controlP5.tab("default").setLabel("ModelT");
      controlP5.controller("strokeWeight").moveTo("agent");
      controlP5.controller("strWeight").moveTo("agent");
      controlP5.controller("optinum").moveTo("agent");
      controlP5.controller("dist").moveTo("agent");
      controlP5.tab("agent").setColorForeground(0xffff0000);
      controlP5.tab("agent").setColorBackground(0xff330000);
      controlP5.trigger();
      controlP5.tab("agent").activateEvent(true);
      controlP5.tab("agent").setId(1);
25. 
    }
26. 
    void controlEvent(ControlEvent theEvent) {
      switch(theEvent.controller().id()) {
        case(2):
        strWeight = (int)(theEvent.controller().value());
        break;
        case(3):
        optinum();
        break;
        case(4):
        Optdist = (int)(theEvent.controller().value());
        break;
      }
    }
28. void keyPressed() {
29.   if(key=='f') {
        output = createWriter("output"  +".txt");
30.     for(int i = 0; i < points.size(); i++) {
          PVector d = (PVector) points.get(i);
          output.println(d.x + "," + d.y + "," + d.z);
        }
31. 
        output.flush();
        output.close();
      }
32.   if (key == 'r' || key == 'R' && !rendered) {
        saveFrame("capture.png");
        //Glossy   
        jr.setShader("object1", "Red");
        jr.setSC("ambient.sc");   
        rendered = jr.render("bucket");    
        // render using render("ipr") to render quick and rough,  
        // and render("bucket") to render slow and smooth   
        // if successfully rendered, render() returns true
      }
    }
    
33. class kPoint {
      //states
      PVector pos;
      float magnatude;
34.   //constructor
      kPoint(PVector _pos, float _magnatude) {
        pos = _pos;
        magnatude = _magnatude;
      }
35.   void render() {
36.     pushMatrix();
        //strokeWeight(strWeight);
        //stroke(magnatude, 0, 0);
        translate(pos.x, pos.y, pos.z);
37.     box(10);
        //point(0,0,0);
        //point(pos.x, pos.y, pos.z);
        popMatrix();
      }
    }

1. import processing.opengl.*;
   import peasy.*;
   import controlP5.*;
2. kWorld world1;
   PeasyCam cam;
   ControlP5 controlP5;
   PMatrix3D currCameraMatrix;
   PGraphics3D g3;
3. int population = 500;
4. boolean alignment_enabled = false;
   boolean coh_enabled = false;
   boolean sep_enabled = false;
   boolean wander_enabled = false;
   boolean steer_enabled = false;
5. void setup(){
6.   size(1200,800,P3D);
     //frameRate(30);
     smooth();
     world1 = new kWorld();
     population();
    
     g3 = (PGraphics3D)g;
     cam = new PeasyCam(this, 2000);
     controlP5 = new ControlP5(this);
     control();
     controlP5.setAutoDraw(false);
7. 
   }
8. void population(){
9.   world1 = new kWorld();
     for (int i = 0; i < population; i++) {
       world1.addAgent(new kAgent(new PVector(random(150,width),random(0,height)), new PVector(random(-1,1),random(-1,1)),random(3,5), random(0.1,0.3)));
     }
   }
10. void draw(){
      background(0); 
      //fill(100);
      //rect(0,0,150,height);
      fill(255);
      PFont font;
      font = loadFont("SansSerif.bold-10.vlw");
      textFont(font,20);
      textMode(SCREEN);
      text("MODELT 2010",0,height-20);
      //stroke(128); 
      //fill(255);
      world1.run();
11.   gui();
12. 
    }
13. void gui() {
      currCameraMatrix = new PMatrix3D(g3.camera);
      camera();
      controlP5.draw();
      g3.camera = currCameraMatrix;
    }
15. void control(){ 
      //population
      controlP5.addSlider("population",0,2000,500,0,0,80,20).setId(1);
      controlP5.controller("population").setLabel("population");
      //alignment
      controlP5.addBang("alignment",0,40,80,20).setId(2);
      controlP5.controller("alignment").setLabel("alignment");
      //cohesion
      controlP5.addBang("cohesion",0,80,80,20).setId(3);
      controlP5.controller("cohesion").setLabel("cohesion");
      //separation
      controlP5.addBang("separation",0,120,80,20).setId(4);
      controlP5.controller("separation").setLabel("separation");
      //wander
      controlP5.addBang("wander",0,160,80,20).setId(5);
      controlP5.controller("wander").setLabel("wander");
      //steer
      controlP5.addBang("steer",0,200,80,20).setId(6);
      controlP5.controller("steer").setLabel("steer");
     
16. }
17. void controlEvent(ControlEvent theEvent) {
      switch(theEvent.controller().id()) {
        case(1):
        population = (int)(theEvent.controller().value());
        //println("population" + population);
        population();
        break;
        case(2):
        alignment_enabled = !alignment_enabled;
        break;
        case(3):
        coh_enabled = !coh_enabled;
        break;
        case(4):
        sep_enabled = !sep_enabled;
        break;
        case(5):
        wander_enabled = !wander_enabled;
        break;
        case(6):
        steer_enabled = !steer_enabled;
        break;
      }
    }
19. class kAgent{
20.   PVector        vel;
      PVector        pos;
      float        maxVel;
      float        maxForce;
      float        wandertheta;
21.   // constructor
      kAgent(
      PVector _pos,
      PVector _vel,
      float _maxVel,
      float _maxForce){
22.     pos = _pos;
        vel = _vel;
        maxVel = _maxVel;
        maxForce = _maxForce;
23.   }
24. 
      // calculates new location
      void update(ArrayList pop){ 
        //set acc to 0
        PVector acc = new PVector(0,0);
25.     // Alignment
        if(alignment_enabled){
          PVector ali = align(pop);    
          ali.mult(1.0);
          acc.add(ali);
        }
26.     // Cohesion
        if(coh_enabled){
          PVector coh = cohesion(pop); 
          coh.mult(1.0);
          acc.add(coh);
        }
27.     // Separation
        if(sep_enabled){
          PVector sep = separate(pop);
          sep.mult(5.0);
          acc.add(sep);
        }
28.     // wander
        if(wander_enabled){
          PVector wander = wander();
          wander.mult(0.5);
          acc.add(wander);
        }
29.     // steer
        if(steer_enabled){
          PVector seek = steer(new PVector(mouseX,mouseY));
          seek.mult(1);
          acc.add(seek);
        }
30.     // add acc to vel
        vel.add(acc);
        // limit vel to maxVel
        vel.limit(maxVel); 
        // add vel to pos
        pos.add(vel);
        acc.set(0,0,0);  // reset acc to 0 each iteration
31.     borders();
        render();
32.   }
33. 
      // seek
      /*
      void seek(PVector target) {
       acc.add(steer(target));
       }
       */
34.   // steer
      PVector steer(PVector target) {
        PVector steer;  // The steering vector
        target.sub(pos);
        float distance = target.mag();
35.     if (distance > 0) {
          target.normalize();
          target.mult(maxVel);
          target.sub(vel);
          //steer = kVec.clone(target);
          target.limit(maxForce);
        }
        else {
          target = new PVector(0,0);
        }
        return target;
      }
36.   // wander
      PVector wander() {
        float wanderR = 16;        
        float wanderD = 60;        
        float change = 0.25;
        wandertheta += random(-change,change);    
37.     PVector circleloc = new PVector(vel.x, vel.y);
        circleloc.normalize();           
        circleloc.mult(wanderD);         
        circleloc.add(pos);             
38.     PVector circleOffSet = new PVector(wanderR*cos(wandertheta),wanderR*sin(wandertheta));
        circleOffSet.add(circleloc);
        //acc.add(steer(circleOffSet));
        PVector vec = steer(circleOffSet);
        return vec;
      } 
39. 
      // separation
      PVector separate (ArrayList pop) {
        float desiredseparation = 25.0;
        PVector sum = new PVector(0,0,0);
        int count = 0;
40.     for (int i = 0 ; i < pop.size(); i++) {
          kAgent other = (kAgent) pop.get(i);
          float dist = pos.dist(other.pos);
          // if the distance is greater than 0 and less than an arbitrary amount (0 when you are yourself)
          if ((dist > 0) && (dist < desiredseparation)) {
            // calculate vector pointing away from neighbor
            PVector diff = new PVector(pos.x, pos.y);
            diff.sub(other.pos);
            diff.normalize();
            diff.mult(1/dist);          // weight by distance
            sum.add(diff);
            count++;                     // keep track of how many
          }
        }
        // average -- divide by how many
        if (count > 0) {
          sum.mult(1/(float)count);
        }
        return sum;
      }
41. 
      // alignment
      PVector align (ArrayList pop) {
        float neighbordist = 50.0;
        PVector sum = new PVector(0,0);
        int count = 0;
        for (int i = 0 ; i < pop.size(); i++) {
          kAgent other = (kAgent) pop.get(i);
          float dist = pos.dist(other.pos);
          if ((dist > 0) && (dist < neighbordist)) {
            sum.add(other.vel);
            count++;
          }
        }
        if (count > 0) {
          sum.mult(1/(float)count);
          sum.limit(maxForce);
        }
        return sum;
      }
42. 
      // cohesion
      PVector cohesion (ArrayList pop) {
        float neighbordist = 50.0;
        PVector sum = new PVector(0,0);  
        int count = 0;
        for (int i = 0 ; i < pop.size(); i++) {
          kAgent other = (kAgent) pop.get(i);
          float dist = pos.dist(other.pos);
          if ((dist > 0) && (dist < neighbordist)) {
            sum.add(other.pos); // Add location
            count++;
          }
        }
        if (count > 0) {
          sum.mult(1/(float)count);
          return steer(sum);  // steer towards the location
        }
        return sum;
      }
43. 
      void render() {
        fill(200);
        stroke(255);
        ellipse(pos.x,pos.y,10,10);
      }
44. 
      void borders() {
        if ((pos.x < 150 && vel.x < 0)||(pos.x > width && vel.x > 0)) {
          //pos.x = width;
          vel.x = -vel.x * 0.95;
        }
        if ((pos.y < 10 && vel.y < 0)||(pos.y > height - 10 && vel.y > 0)) {
          //pos.y = height;
          vel.y = -vel.y * 0.95;
        }
      }
45. }
47. class kWorld {
      ArrayList population;
     
      kWorld() {
         population = new ArrayList(); // initialize the arraylist
      }
48.   // cycles through each agent passing the population to it
      void run(){
        for (int i = 0; i < population.size(); i++) {
          kAgent a = (kAgent) population.get(i); 
          a.update(population);
        }
      }
49.   // add agent
      void addAgent(kAgent a) {
        population.add(a);
      }
50. }