float theta = 0.0;

void setup() {
  size (200,200,P3D);
}

void draw() {
  background(144);
  theta+= 0.01;
  
  translate(100,100,0);
  rotateX(theta);
  rotateY(theta);
  drawPyramid(50);
  
  translate(50,50,20);
  
  drawPyramid(10);  
}

void drawPyramid(int t) {
  stroke(0);
  
  fill(150,0,0,127);
  beginShape(TRIANGLES);
  vertex(-t,-t,-t);
  vertex(t,-t,-t);
  vertex(0,-0-t);
  
  fill(0,150,0,127);
  vertex(t,-t,-t);
  vertex(t,t,-t);
  vertex(0,0,t);
  
  fill(0,0,150,127);
  vertex(t,t,-t);
  vertex(-t,t,-t);
  vertex(0,0,t);
  
  fill(150,0,150,127);
  vertex(-t,t,-t);
  vertex(-t,-t,-t);
  vertex(0,0,t);
  endShape();
}