Combining IFC and 3D tiles to create 3D visualization for building information modeling

Integrating two critical technologies, Building Information Modeling (BIM) and Geographic Information System (GIS), can bring excellent results into digital construction. However, a point of contention in this integration has yet to be resolved. In view of the shortcomings of the network transmission and browser rendering of current integrated BIM-GIS schemes, accordingly the 3D Tiles data format using Web Graphics Library (WebGL) as the standard for rendering 3D models has been widely considered in recent years. This study provides an implementation plan for data integration and information interaction between BIM and GIS. It aims to improve the traditional model simplification processing solution, analyze the current insufficient network transmission and browser rendering ability of the BIM and GIS integration scheme, and transform the BIM model from the Industry Foundation Classes (IFC) into the 3D Tiles data format. In this study, IFC standard files are first exported as the data source, and the mapping relationship between BIM files and 3D Tiles files is analyzed. The integral IFC model is then reorganized to form JSON files associated with semantic attributes and building component models with geometric information. The proposed relationship mapping allows the attribute contained in the IFC models to be delivered to 3D tiles. Meanwhile, the coordinate transformation, data mapping, spatial index, and Level of Details (LOD) hierarchical division are completed during conversion to ensure fast and efficient rendering interaction of BIM data and geographical features in the 3D WebGIS framework. The experiment results indicated that users can quickly load the BIM model on the Web site, which may be viewed as a feasible solution for the large-scale data integration of GIS and BIM on the Web site.