Spinning Dots Triangles Circle -- processing code that created https://www.youtube.com/watch?v=4LWCJvquuvo

SpinningDotsTrianglesCircle.pde

int W=1280;
int H=720;
int N=16;
boolean SAVE_FRAMES=false;
float DT = 1.0/30.0;

float time;
int frame;

float[] dots_speed;
float[] dots_rad;
float dots_size;
PVector[] dots_loc;
PVector center;

void start() {
  size(W, H);
  frameRate(30);
  smooth(4);
  dots_speed = new float[N];
  dots_rad = new float[N];
  dots_loc = new PVector[N];
  for (int i = 0; i < N; i++) {
    dots_speed[i] = 0.5 + i*0.1;
    dots_rad[i] = 25 + i*25;
    dots_loc[i] = new PVector(0, 0);
  }
  center = new PVector(W/2, H/2);
  dots_size = 3.0;
  time = 0;
}

void draw() {
  background(0);
  color(255);
  strokeWeight(1.5);
  updateDots();
  drawDots();
  drawLines();
  drawCircles();
  
  if (SAVE_FRAMES) { // && ((frame % 5) == 0)) {
    saveFrame("a-####.png");
  }
  
  time += DT;
  frame += 1;
}

void updateDots() {
  for (int i = 0; i < N; i++) {
    dots_loc[i].x = center.x + dots_rad[i]*cos(time*dots_speed[i]);
    dots_loc[i].y = center.y + dots_rad[i]*sin(time*dots_speed[i]);
  }
}

void drawDots() {
  fill(255);
  for (int i = 0; i < N; i++) {
    ellipse(dots_loc[i].x, dots_loc[i].y, 2*dots_size, 2*dots_size);
  }
}

void drawLines() {
  fill(0, 0);
  stroke(255);
  for (int i = 0; i < N-2; i++) {
    beginShape();
    vertex(dots_loc[i].x, dots_loc[i].y);
    vertex(dots_loc[i+1].x, dots_loc[i+1].y);
    vertex(dots_loc[i+2].x, dots_loc[i+2].y);
    endShape(CLOSE);
  }
}

void drawCircles() {
  fill(0, 0);
  stroke(255, 255, 0);
  for (int i = 0; i < N - 2; i++) {
    PVector c = circleCenter(dots_loc[i+0], dots_loc[i+1], dots_loc[i+2]);
    float r = PVector.dist(c, dots_loc[i+0]);
    ellipse(c.x, c.y, 2*r, 2*r);
  }
}

PVector circleCenter(PVector A, PVector B, PVector C) {
  float yDelta_a = B.y - A.y;
  float xDelta_a = B.x - A.x;
  float yDelta_b = C.y - B.y;
  float xDelta_b = C.x - B.x;
  PVector center = new PVector(0, 0);

  float aSlope = yDelta_a/xDelta_a;
  float bSlope = yDelta_b/xDelta_b;  
  center.x = (aSlope*bSlope*(A.y - C.y) + bSlope*(A.x + B.x)
    - aSlope*(B.x+C.x) )/(2* (bSlope-aSlope) );
  center.y = -1*(center.x - (A.x+B.x)/2)/aSlope +  (A.y+B.y)/2;

  return center;
}