void setup()
{
  size(256, 256);
  background(255);
  noStroke();
}

int frame = 0;
int damping = 16;

void draw()
{
  frame = frame + 1;
  
  float maxDistance = sqrt(31 * 31 + 31 * 31);

  for (int y = 0; y < 32; y++)
  {
    for (int x = 0; x < 32; x++)
    {
      float distance = sqrt(x * x + y * y);
      float grayLevel = abs(sin(distance / maxDistance * frame / damping * PI));
      
      fill(255 * grayLevel);
      
      float originX = x * 256 / 32 + 1 + 2.5;
      float originY = y * 256 / 32 + 1 + 2.5;
      
      ellipse(originX, originY, 5, 5);
    }
  }
}