几层背景（如视差）

I am trying to create a background for my game that gives the impression that some things are further than the others. so lets say i have a sky, a sun, some clouds and the ground. the sky and the sun are the furthest, the clouds in the middle and the ground is in the front. now if the player zooms or pans the camera i want the further layers to move less than the closer layers to give the impression that they are really further (the ground moves the most and the clouds move less and the sun almost doesn't move) just like the way auto parallax behave except that it is a static background so normally nothing moves unless the players zooms in or out.I am trying to create a background for my game