Generation of navigation graphs for indoor space

This article proposes a comprehensive approach to computing a navigation graph for an indoor space. It focuses on a single floor, but the work is easily extensible to multi-level spaces. The approach proceeds by using a formal model, based on the combinatorial map but enhanced with geometric and semantic information. The process is almost fully automatic, taking as input the building plans providing the geometric structure of the floors and semantics of the building, such as functions of interior spaces, portals, etc. One of the novel aspects in this work was the use of combinatorial maps and their duals to provide a compact formal description of the topology and connectivity of the indoor structure represented by a connected, embedded graph. While making use of existing libraries for the more routine computational geometry involved, the research develops several new algorithms, including one for computing the local kernel of a region. The process is evaluated by means of a case study using part of a university building

Navigation Queries from Triangular Meshes

Abstract. Navigation meshes are commonly employed as a practical represen-tation for path planning and other navigation queries in animated virtual envi-ronments 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, track-ing moving obstacles, ray–obstacle intersection queries, path planning with arbi-trary 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 pas-sages of the mesh. This paper shows that triangular meshes can support the effi-cient computation of several navigation procedures and an implementation of the presented methods is available