(x,y,z,t,&r,&g,&b){
  
   t *= 0.4;
   
   dx0 = (x - sin(t * 3));
   dy0 = (y - cos(t * 2));
   dz0 = (z - cos(t * 2));
   
   dx1 = (x - cos(t * 2));
   dy1 = (y - sin(t * 5));
   dz1 = (z - cos(t * 3));
   
   dx2 = (x - cos(t * 2));
   dy2 = (y - cos(t * 3));
   dz2 = (z - sin(t * 5));
   
   b0 = dx0 * dx0 + dy0 * dy0 + dz0 * dz0;
   b1 = dx1 * dx1 + dy1 * dy1 + dz1 * dz1;
   b2 = dx2 * dx2 + dy2 * dy2 + dz2 * dz2;
   
   r = 255 - b0 * 255;
   g = 255 - b1 * 255;
   b = 255 - b2 * 255;
   
   return  1 - (b0 * b1 * b2);
}