Simplifying and Exchanging 3D Utility Network Objects Using City Models

City models are extended recently to include utilities infrastructure e.g. CityGML/Utility Network ADE. The 3D geometry representation in these models is utilizing the concept of boundary representation (B-Rep), where planar faces and straight edges enclose the boundary. In case of utilities network, B-Rep would result in an extensive amount of storage space. This paper presents a new data type compatible to the swept representation, as well as the required algorithm to extract the needed information from the 3D utility network object represented as (B-Rep), i.e. centerlines as well as their profile information, and store them in the new custom data type. Another algorithm allows the generation of B-rep for visualization purposes. To show the effectiveness of the presented approach we accomplished the export of utility network into CityGML UtiltiyNetworkADE. Several 3D network object types (e.g. pipes, fitting) are exported to the new data type. The tests show the feasibility of the data type to reduce storage space, to create B-rep for visualization as well as to extract a graph for analysis. The new data types as well as the mentioned algorithms are implemented in Spatial-DBMS.