CityJSON Reader/Writer

The CityJSON module enables FME to read and write files in the CityJSON format.

The CityJSON format is maintained by the 3D Geoinformation group at the TU Delft. For more information, see https://www.cityjson.org/.

CityJSON is an OGC® Community Standard.

CityJSON Product and System Requirements

Format

Product

Operating System

Reader/Writer

FME Desktop License

FME Server

FME Cloud

Windows

Linux

Mac

Reader

Available in FME Professional Edition and higher

Yes

Yes

32-bit: Yes

64-bit: Yes

Yes

Yes

Writer

Available in FME Professional Edition and higher

Yes

Yes

32-bit: Yes

64-bit: Yes

Yes

Yes

Overview

This documentation assumes familiarity with JSON and the CityJSON format.

CityJSON is a JSON-based encoding for storing 3D city models, also called digital maquettes or digital twins.

The current version of CityJSON (v1.0.1) is an alternative encoding to XML/GML for the CityGML data model v2.0.0 (The schema of CityGML can be downloaded from the Open Geospatial Consortium (OGC) website).

This schema specifications can be found at the CityJSON website.

Reader Overview

This reader supports CityJSON datasets conforming to the publicly available CityJSON v1.0.1 schemas.

The CityJSON reader reads all parts of a file.

The reader supports datasets that contain Extensions natively (similar to CityGML ADEs).

Writer Overview

This writer supports writing of CityJSON v1.0.1 files.

Any of the supported city objects of CityJSON can be written to a CityJSON file, and city objects belonging to an Extension can be written (but their name/type must begin with a plus "+" symbol).

However, there is not yet a way to automatically write the extensions property at the root of the CityJSON file. (This enhancement is planned in a future version of this format.)

The traits of a face geometry will only be written if the geometry name is one of the enumerated CityJSON semantics for the CityJSON Semantic Surface Object represented by the feature type. For more information, see CityJSON Specifications 1.0.1 from OGC on the Semantic Surface Object.