METHOD FOR INCORPORATING HIGH DETAIL NORMAL VECTOR INFORMATION INTO POLYGONAL TERRAIN DATABASES AND IMAGE DISPLAY SYSTEM WHICH IMPLEMENTS THIS METHOD

An improvement over existing image display systems which utilize polygonal terrain databases, e.g., such as are used in RADAR simulation and image generation systems for flight simulators, the improvement residing in a method for modifying the polygon faces in the existing terrain database by replacing the constant normal vectors thereof with non-constant normal vectors derived from a higher-detailed terrain database of the same geographical area, to thereby produce a modified polygonal terrain database which enables the generation of images in which the terrain of the scene being displayed is represented by textured polygons, as opposed to polygon faces of constant intensity. The present invention also encompasses an image display system programmed to implement this method.