Method for operating navigation system to perform sharp three-dimensional representation of feature polygons e.g. river, in two-dimensional map, involves determining whether point is found inside or outside surface element on basis of tree

摘要

The method involves converting a polygon into a binary-space partitioning (BSP) tree, and storing the BSP tree. A determination is made whether a point is found inside or outside a surface element on the basis of the BSP tree. A section line of the polygon in the BSP tree is stored on the basis of Hessian standard format (HNF) coefficients. Sectors are labeled separately. Entrance nodes are determined from the BSP tree.