1. A method for simulating the effects of layered fog having at least one texture applied thereto, to thereby accurately render position and horizontal movement information in a computer-generated synthetic environment that is rendered on a display screen, thus providing at least visual velocity clues to an observer thereof, said method comprising the steps of: (1) applying the at least one texture to the layered fog; and (2) blending color modulation, density modulation, local texture effects and global texture effects such that each layer of the layered fog has an appearance of finite thickness instead of only appearing as a texture plane.