Rendering global macro texture, for producing a dynamic image, as on computer generated terrain, seen from a moving viewpoint

摘要

A dynamic terrain display is created from digitized grid post data as a height field, that is textured using maps embracing progressively larger areas with increasing remoteness from the viewpoint. A truncated pyramid is defined by map parts for each level that are maintained in active memory. The map parts or fragments are stored in rectangular configurations to be updated row-by-row or column-by-column, by overwriting obsolete data in a circular manner to reflect changes in the viewpoint. Levels of the map parts accordingly are paged independently of each other from database storage. Not all levels are required to have texture in that if a level is not available, a lower level can be employed. Theme cells also can be utilized.