Polygon hexagon, octagon;

void setup() {
  hexagon = new Polygon(color(0, 255, 0, 100), color(255), 6);
  hexagon.addVertex(30, 65);
  hexagon.addVertex(86, 200);
  hexagon.addVertex(90, 210);
  hexagon.addVertex(200, 180);
  hexagon.addVertex(70, 100);
  
  octagon = new Polygon(color(35, 100, 180, 80), color(255), 8);
  for (int i=0; i<8; i++)
    octagon.addVertex();

  size(300, 300);
  smooth();
  frameRate(20);
}

void draw() {
//  background(0);
  fill(0, 30);
  noStroke();
  rect(0, 0, width, height);
  hexagon.drawPolygon();
  if (frameCount%4 == 0)
    hexagon.replaceVertex(int(random(0, hexagon.i)));
  octagon.drawPolygon();
  if (frameCount%9 == 0)
    octagon.replaceVertex(int(random(0, octagon.i)));
  
}