TERRAIN SEASCAPE IMAGE GENERATOR WITH MATH MODEL DATA BASE

摘要

TERRAIN/SEASCAPE IMAGE GENERATORWITH MATH MODEL DATA BASEAbstract of the DisclosureA technique for the real-time computer generationof visual scenes of rolling terrain and sea waves is basedon a view ray approach wherein an azimuth sweep is definedand an image profile is generated by incrementing rangesteps from the view point but employs a data base which isan on-line math model consisting of a summation of cosinefunctions rather than a grid data base. Math models aregenerated separately for both land and sea elevation postsfor the scene to be generated. A horizontal field of viewis defined as a predetermined number of increments betweensweeps perpendicular to a boresight from a view point,and a vertical field of view is defined as a predeterminednumber of increments between view rays perpendicular tothe boresight from the view point. The change in rangeis incremented along the boresight from the view point,and for each range increment, the view ray is steppeddown by an increment corresponding to an increment changein the tangent of the view angle. An elevation value ofthe view ray is accumulated for each incremented changein the tangent of the view angle. For each rangeincrement, the math model forthe land elevation postsis compared with the math model for the seal elevation posts,and the larger of the two is selected. At each rangeincrement, the accumulated elevation value of the viewray is compared with the selected math model of elevationposts and, if a view ray strikes the selected elevationpost, the data for that post is read to a display; other-wise, the math models of the land and sea elevation postsare incremented.