untitled

int frames=240, num=50;
float theta, rotAngle;

void setup() {
  size(540, 540);
  smooth(8);
  noFill();
  stroke(255, 150);
  background(0);
}

void draw() {
  background(0);
  float t = (frameCount%frames)/float(frames);
  rotAngle = map(t, 0, 1, 0, TWO_PI)* ease(t, 2, 1);
  float sc = map(sin(theta+rotAngle*2), -1, 1, 1, 4);
  for (int i=0; i<num; i++) {
    pushMatrix();
    translate(width/2, height/2);
    rotate(TWO_PI/num*i);
  float x = map(sin(theta+rotAngle+TWO_PI/num*i*2), -1, 1, 30, 200);
    ellipse(x, 0, 30, 30*sc);
    popMatrix();
  }
  theta += TWO_PI/frames;
  //if (frameCount<=frames) saveFrame("image-###.gif");
}

float ease(float t, float e) {
  return t < 0.5 ? 0.5 * pow(2*t, e) : 1 - 0.5 * pow(2*(1 - t), e);
}

float ease(float t, float in, float out) {
  return (1-t)*ease(t, in) + t*ease(t, out);
}