4.4.6.9. CityJSON options

Note

These preference settings only apply to CityJSON input files.

Fig. 4.27 Import preferences – CityJSON options.

CityJSON offers an extension mechanism similar to CityGML Application Domain Extensions (ADEs). A CityJSON Extension allows to extend the core data model of CityJSON by adding new attributes to predefined city objects, defining new city object types and adding additional properties to the root of a document.

The 3D City Database has support for storing and managing CityGML ADEs in extra tables that seamlessly integrate with the 3DCityDB core schema (see Section 3.2.16). The mechanisms can also be used for CityJSON Extensions but then also requires a Java extension package for the Importer/Exporter (see Section 5.3.6).

In contrast to CityGML datasets, the Importer/Exporter can parse CityJSON Extensions in a more generic way and map new city object types to GenericCityObject instances and additional attributes of city objects to generic attributes. This way, the extension data is not lost and can be stored in the core 3DCityDB schema without the need for extra tables. Please note that the data will, of course, also be exported as generic objects and attributes again so that the original CityJSON Extension structure cannot be restored. If you want to handle CityJSON Extensions in this generic way, simply enable the corresponding option in the above preference settings dialog.