Boundary representation-based implementation of spatial BIM queries

The computer-aided spatial analysis of building models is an important feature for efficient data management and productive downstream processes in Building Information Modelling. Users of building models have to deal with complex data sets. At the same time, it is also important to have a deep understanding of the functionality and design of a building. Topological and directional queries provide a means of gaining insights into the spatial structure of even a large-scale project. To handle the massive amount of data involved in these projects, the previously introduced Spatial Query Language for Building Information Models is extended by a new, more efficient approach for its topological and directional predicates. Instead of the Octree representation of components employed in the past, the new methods operate directly on the boundary representation, i.e. triangulated meshes. In addition, R-Trees are used for a two-stage spatial indexing of the scene. This makes it possible to achieve a substantial improvement in performance for topological and directional predicates of the Spatial Query Language.