Extending CityGML for IFC-sourced 3D city models

• Published in: Automation in construction 2021-01, Vol.121, p.103440, Article 103440
• Main Authors: Biljecki, Filip, Lim, Joie, Crawford, James, Moraru, Diana, Tauscher, Helga, Konde, Amol, Adouane, Kamel, Lawrence, Simon, Janssen, Patrick, Stouffs, Rudi
• Format: Article
• Language: English
• Subjects: 3D city model; ADE; BIM; CityGML; IFC; Singapore; Three dimensional models
• ISSN: 0926-5805; 1872-7891
• DOI: 10.1016/j.autcon.2020.103440

Differences in the scope and intent of the contrasting IFC and CityGML data formats entail that converting the former to the latter results in loss of information. However, for some use cases it is beneficial to keep also particular information from IFC that is not native to CityGML, and achieving that requires mechanisms such as the CityGML Application Domain Extension (ADE). We develop an ADE to support retaining relevant information from IFC. Besides being driven by the particular source of the input data (IFC), this multi-purpose ADE is shaped after a discovery process that involved examining potentially applicable use cases in Singapore, doubling as an extension that is adapted to a set of use cases and the local geographic context. We implement the conceptual work by generating an enriched dataset (with an automatic conversion from IFC to CityGML), visualising it, and discuss its added value in a use case. [Display omitted] •Conversion from IFC to CityGML entails loss of information.•Preserving a certain subset of information from IFC is beneficial for some use cases.•We investigate which information is relevant for particular scenarios in Singapore.•We develop an extension to CityGML to preserve additional information.•We demonstrate the relevance of the work with an implementation.