processingdrawings:

mobile[] mobiles; 
void setup() { 
  size(640, 640); 
  background(255); 
  colorMode(HSB); 
  mobiles = new mobile[0]; 
  for (int b=0; b< 14; b++) { 
    float ray=(width*0.45-b*14); 
    float perimetre = 2*PI*ray; 
    int numba = int(perimetre/20); 
    float toupiecent=TWO_PI/numba; 
    float couleur=255/numba; 
    for (int a=0; a< numba; a++) { 
      new mobile(width/2+cos(toupiecent*a)*ray, height/2+sin(toupiecent*a)*ray, 
      color(couleur*a, (255.0/14)*(b+1), 255));
    }
  } 
  stroke(0, 100);
} 
void draw() { 
  for (int a=0; a< mobiles.length; a++) { 
    mobiles[a].draw();
  }
} 
class mobile { 
  float x, y, an, v, endx, endy; 
  float[] vrange; 
  color c; 
  mobile(float _endx, float _endy, color _c) { 
    endx=_endx; 
    endy=_endy; 
    c=_c; 
    x=random(width); 
    y=random(height); 
    v=random(0.5, 2.1); 
    vrange=new float[2]; 
    vrange[0]=random(-0.5, -0.1); 
    vrange[1]=random(0.1, 0.5); 
    an=random(TWO_PI); 
    mobiles = (mobile[]) append (mobiles, this);
  } 
  void draw() { 
    fill(c); 
    an+=random(vrange[0], vrange[1]); 
    x+=cos(an)*v; 
    y+=sin(an)*v; 
    if (x<
    0||y<
    0||x>
    width||y>
    height) { 
      an+=random(-PI, PI); 
      x=constrain(x, 0, width); 
      y=constrain(y, 0, height);
    } 
    if (random(30)<
    1) { 
      an=atan2(endy-y, endx-x); 
      vrange[0]=random(-0.5, -0.1); 
      vrange[1]=random(0.1, 0.5);
    } 
    if (dist(x, y, endx, endy)<
    1.7) { 
      x=endx; 
      y=endy; 
      v*=0.97;
    } 
    for (int a=0; a< mobiles.length; a++) { 
      mobile m=mobiles[a]; 
      if (m!=this) { 
        float da=dist(m.x, m.y, x, y); 
        if (da<
        10) { 
          m.x=x+(m.x-x)/da*(da+1); 
          m.y=y+(m.y-y)/da*(da+1);
        }
      }
    } 
    ellipse(x, y, 10, 10);
  }
} 
void keyReleased() { 
  saveFrame("img#####.png");
}