speed it travels relative to you? I have known this for awhile, but it just started to bother me: while driving, trees that are closer to me move quicker than the ones further away, relative to me and in my vision. 2D platforming games do this too, having several backgrounds and scrolling the background furthest away slowest to create a perception of depth. What I am wondering is if there is an equation to determine the speed of an image based on how far away it is.