1. In a computer system, a method of efficiently rendering a complex scene, said complex scene including a plurality of objects, the method comprising the steps of: a) designating a first set of said plurality of objects as potential occluders; b) providing a first memory section for storing a first plurality of Z-values corresponding to a first depth-level of said first set; and c) providing a second memory section for storing a second plurality of Z-values corresponding to a second depth-level of said first set, wherein a single pixel corresponds to one of said first plurality of Z-values and to one of said second plurality of Z-values.