Navigation Queries from Triangular Meshes

Navigation meshes are commonly employed as a practical representation for path planning and other navigation queries in animated virtual environments and computer games. This paper explores the use of triangulations as a navigation mesh, and discusses several useful triangulation–based algorithms and operations: environment modeling and validity, automatic agent placement, tracking moving obstacles, ray–obstacle intersection queries, path planning with arbitrary clearance, determination of corridors, etc. While several of the addressed queries and operations can be applied to generic triangular meshes, the efficient computation of paths with arbitrary clearance requires a new type of triangular mesh, called a Local Clearance Triangulation, which enables the efficient and correct determination if a disc of arbitrary size can pass through any narrow passages of the mesh. This paper shows that triangular meshes can support the efficient computation of several navigation procedures and an implementation of the presented methods is available.