A method and apparatus for managing memory usage for three-dimensional computer graphics systems are provided. A scene which is textured and shaded in the system is divided into a plurality of rectangular areas, each including a plurality of picture elements in the scene. For each rectangular area a list of objects which may be visible in the scene is derived. Objects which do not contribute to the final textured and shaded scene are then removed from each list and the rectangular area is then textured and shaded using reduced lists of objects.