THE EXTRACTION OF INDOOR BUILDING INFORMATION FROM BIM TO OGC INDOORGML

Abstract. Indoor Spatial Data Infrastructure (indoor-SDI) is an important SDI for geosptial analysis and location-based services. Building Information Model (BIM) has high degree of details in geometric and semantic information for building. This study proposed direct conversion schemes to extract indoor building information from BIM to OGC IndoorGML. The major steps of the research include (1) topological conversion from building model into indoor network model; and (2) generation of IndoorGML. The topological conversion is a major process of generating and mapping nodes and edges from IFC to indoorGML. Node represents every space (e.g. IfcSpace) and objects (e.g. IfcDoor) in the building while edge shows the relationships between nodes. According to the definition of IndoorGML, the topological model in the dual space is also represented as a set of nodes and edges. These definitions of IndoorGML are the same as in the indoor network. Therefore, we can extract the necessary data in the indoor network and easily convert them into IndoorGML based on IndoorGML Schema. The experiment utilized a real BIM model to examine the proposed method. The experimental results indicated that the 3D indoor model (i.e. IndoorGML model) can be automatically imported from IFC model by the proposed procedure. In addition, the geometric and attribute of building elements are completely and correctly converted from BIM to indoor-SDI.