Space Junk by Ira Greenberg. Zoom suggestion by Danny Greenberg.

Rotating cubes in space using a custom Cube class. Color controlled by light sources. Move the mouse left and right to zoom.

import processing.opengl.*;

// Used for oveall rotation
float ang;

// Cube count-lower/raise to test P3D/OPENGL performance
int limit = 500;

// Array for all cubes
Cube[]cubes = new Cube[limit];

void setup() {
  size(1024, 768, OPENGL); 
  background(0); 
  noStroke();

  // Instantiate cubes, passing in random vals for size and postion
  for (int i = 0; i< cubes.length; i++){
    cubes[i] = new Cube(int(random(-10, 10)), int(random(-10, 10)), 
    int(random(-10, 10)), int(random(-140, 140)), int(random(-140, 140)), 
    int(random(-140, 140)));
  }
}

void draw(){
  background(0); 
  fill(200);

  // Set up some different colored lights
  pointLight(51, 102, 255, 65, 60, 100); 
  pointLight(200, 40, 60, -65, -60, -150);

  // Raise overall light in scene 
  ambientLight(70, 70, 10); 

  // Center geometry in display windwow.
  // you can change 3rd argument ('0')
  // to move block group closer(+)/further(-)
  translate(width/2, height/2, -200 + mouseX * 0.65);

  // Rotate around y and x axes
  rotateY(radians(ang));
  rotateX(radians(ang));

  // Draw cubes
  for (int i = 0; i < cubes.length; i++){
    cubes[i].drawCube();
  }
  
  // Used in rotate function calls above
  ang++;
}






class Cube {

  // Properties
  int w, h, d;
  int shiftX, shiftY, shiftZ;

  // Constructor
  Cube(int w, int h, int d, int shiftX, int shiftY, int shiftZ){
    this.w = w;
    this.h = h;
    this.d = d;
    this.shiftX = shiftX;
    this.shiftY = shiftY;
    this.shiftZ = shiftZ;
  }

  // Main cube drawing method, which looks 
  // more confusing than it really is. It's 
  // just a bunch of rectangles drawn for 
  // each cube face
  void drawCube(){
    beginShape(QUADS);
    // Front face
    vertex(-w/2 + shiftX, -h/2 + shiftY, -d/2 + shiftZ); 
    vertex(w + shiftX, -h/2 + shiftY, -d/2 + shiftZ); 
    vertex(w + shiftX, h + shiftY, -d/2 + shiftZ); 
    vertex(-w/2 + shiftX, h + shiftY, -d/2 + shiftZ); 

    // Back face
    vertex(-w/2 + shiftX, -h/2 + shiftY, d + shiftZ); 
    vertex(w + shiftX, -h/2 + shiftY, d + shiftZ); 
    vertex(w + shiftX, h + shiftY, d + shiftZ); 
    vertex(-w/2 + shiftX, h + shiftY, d + shiftZ);

    // Left face
    vertex(-w/2 + shiftX, -h/2 + shiftY, -d/2 + shiftZ); 
    vertex(-w/2 + shiftX, -h/2 + shiftY, d + shiftZ); 
    vertex(-w/2 + shiftX, h + shiftY, d + shiftZ); 
    vertex(-w/2 + shiftX, h + shiftY, -d/2 + shiftZ); 

    // Right face
    vertex(w + shiftX, -h/2 + shiftY, -d/2 + shiftZ); 
    vertex(w + shiftX, -h/2 + shiftY, d + shiftZ); 
    vertex(w + shiftX, h + shiftY, d + shiftZ); 
    vertex(w + shiftX, h + shiftY, -d/2 + shiftZ); 

    // Top face
    vertex(-w/2 + shiftX, -h/2 + shiftY, -d/2 + shiftZ); 
    vertex(w + shiftX, -h/2 + shiftY, -d/2 + shiftZ); 
    vertex(w + shiftX, -h/2 + shiftY, d + shiftZ); 
    vertex(-w/2 + shiftX, -h/2 + shiftY, d + shiftZ); 

    // Bottom face
    vertex(-w/2 + shiftX, h + shiftY, -d/2 + shiftZ); 
    vertex(w + shiftX, h + shiftY, -d/2 + shiftZ); 
    vertex(w + shiftX, h + shiftY, d + shiftZ); 
    vertex(-w/2 + shiftX, h + shiftY, d + shiftZ); 

    endShape(); 

    // Add some rotation to each box for pizazz.
    rotateY(radians(1));
    rotateX(radians(1));
    rotateZ(radians(1));
  }
}