19 June 2001




R. Ladner
Naval Research Laboratory
Stennis Space Center, MS 39529-5004
M. Abdelguerfi
Computer Science Department
University of New Orleans, LA USA


The Naval Research Laboratory's Digital Mapping, Charting, and Geodesy Analysis Program (DMAP) is investigating the extension of the National Imagery and Mapping Agency's (NIMA) Vector Product Format (VPF) to handle a wide range of non-manifold 3D objects for modeling and simulation. The extended VPF, referred to as VPF+, makes use of a non-manifold data structure for modeling 3D synthetic environments. The data structure uses a boundary representation (B-rep) method. B-rep models 3D objects by describing them in terms of their bounding entities and by topologically orienting them in a manner that enables the distinction between the object's interior and exterior. Consistent with B-rep. the representational scheme of the proposed data structure includes both topologic and geometric information. The topologic information encompasses the adjacencies involved in 3D manifold and non-manifold objects, and is described using a new extended Winged-Edge data structure. This data structure is referred to as "Non-Manifold 3D Winged-Edge Topology". VPF+ also adds a new simple feature class of dimension three, referred to as 3D Object Feature. VPF+ is being prototyped in a Web-based virtual reality application. Functionality includes the ability to walk through or fly over the terrain to move around objects, to enter buildings, display floor plans, etc.3D terrain representation plays

Sponsored by the U.S. Marine Corps Warfighting Lab.

Presented at the SPIE Aerosense Conference in April 1999.
Naval Research Laboratory Contribution Number NRL/PP/7441 99-0001.
Conference Proceedings