Integration of BIM and GIS: IFC geometry transformation to shapefile using enhanced open-source approach

Efficient data exchange is the foundation of effective integration of Building Information Modeling (BIM) and Geographic Information System (GIS). However, it has not been fully achieved. This study aims to enhance the previously developed Open-Source Approach (OSA), which is for geometry transformation of Industry Foundation Classes (IFC) into the shapefile format. OSA will be strengthened to be enhanced OSA (E-OSA) by developing an enhanced Automatic Multipatch Generation (E-AMG) algorithm that is capable of transforming various types of 3D representation, such as clipping and mapped representation, to boundary representation (Brep). The proposed method was tested and validated using a house model and two building models provided by Karlsruhe Institute of Technology (KIT) as well as a bridge model. The results show that E-AMG has the capacity to successfully transform these models from IFC to shapefile without building element loss. A comparison between Data Interoperability Extension for ArcGIS (DIA), Feature Manipulation Engine (FME) and the proposed E-OSA shows that the proposed method is more reliable than others while dealing with complex models. However, this method currently needs human intervention when handling multiple-clipping geometry. This issue should be addressed in the future to improve the effectiveness of E-OSA.