1. A method comprising using a computer to reduce the number of geometry calculations to simulate a three-dimensional environment, the method including: converting an object's three-dimensional location coordinates to two-dimensional location coordinates, the object being located in a simulated three-dimensional environment; converting a three-dimensional scan volume to a two-dimensional scan area, the scan volume corresponding to a scan emanating from an object located in the simulated three-dimensional environment; determining the two-dimensional location coordinates for objects located in the two-dimensional scan area; and determining movements for only those objects located in the two-dimensional scan area using the objects two-dimensional location coordinates.