Bounding box in 3D graphics

摘要

A system and method for processing a graphics primitive for display in a display area defined by a scissoring window. The graphics primitive is part of an object in view space which also includes a near and a far plane and possibly one or more user-defined clipping planes. These planes may affect the portion of the graphics primitive to be rendered in the display area. The graphics primitive is enclosed by a bounding box, which is then reduced, if possible, based on the Znear clipping plane intersecting the graphics primitive. The reduced bounding box is then subjected to the scissoring window if a portion of the bounding box lies outside the window. The final bounding box determines how much of the graphics primitive should be rendered in the display area. This reduces the amount of rendering that is required of the graphics system, and increases the performance of the system.