Spatial augmentation of vertices and continuous level of detail

Abstract

In a computer image generation system, the number of vertices which define each of a plurality of terrain-defining polygons is augmented in real time for providing finer detail and for effecting substantially continuous smooth level of detail (LOD) transition. Augmented vertices may have components that are statistically derived, in which case it is not necessary to store and/or predefine them. Alternatively, some vertex components may have predetermined values derived from mapping data or from other deterministic sources and may be stored in compact form. Processing polygons, typically triangles defined by selected ones of the sum of the augmented vertices and the original vertices, may be used for displaying the finer detail. Statistically derived finer detail is especially suited for providing non-specific detail to features such as terrain, while deterministic data allows highly accurate representations of specific `real world` locations. The decision to augment vertices is controlled by a predetermined breakup criteria, which may be selected as one, or a combination, of: range from the viewpoint; angle from the viewpoint boresight; desired maximum error; and other defined criteria.