From Citygml

CityGML - City Geography Markup Language

The City Geography Markup Language (CityGML) is a new and innovative concept for the modelling and exchange of 3D city and landscape models that is quickly being adopted on an international level. CityGML is a common information model for the representation of 3D urban objects. It defines the classes and relations for the most relevant topographic objects in cities and regional models with respect to their geometrical, topological, semantical and appearance properties. Included are generalization hierarchies between thematic classes, aggregations, relations between objects, and spatial properties. In contrast to other 3D vector formats, CityGML is based on a rich, general purpose information model in addition to geometry and graphics content that allows to employ virtual 3D city models for sophisticated analysis tasks in different application domains like simulations, urban data mining, facility management, and thematic inquiries. Targeted application areas explicitly include urban and landscape planning; architectural design; tourist and leisure activities; 3D cadastres; environmental simulations; mobile telecommunications; disaster management; homeland security; vehicle and pedestrian navigation; training simulators; and mobile robotics.

CityGML is realised as an open data model and XML-based format for the storage and exchange of virtual 3D city models. It is implemented as an application schema for the Geography Markup Language version 3.1.1 (GML3), the extendible international standard for spatial data exchange issued by the Open Geospatial Consortium (OGC) and the ISO TC211. CityGML is an official OGC Standard and can be used free of charge.

The CityGMLWiki is an open portal to publish and share information about CityGML. However, it is not the offical website of the CityGML. Please find the official website of CityGML at http://www.citygml.org.

[ Edit ] Welcome to CityGMLWiki! CityGMLWiki is an open portal for all kind of information around CityGML. Good authors are always welcome – the first steps are very easy! Don't hesitate to login (please use a proper name) and add, correct, and modify the pages. All matters are subject to GNU Free Documentation Licence.

[ Edit ] Note! As OGC is an international organisation and CityGML is an international development authors are kindly asked to contribute articles in English. However external references may include information and documents provided in different languages.

Current News

January 6, 2010

The OGC seeks input on the next revision of CityGML (see official OGC press release). The public is invited to submit change requests, proposed additions as well as suggestions for the future development of CityGML. The deadline for submissions is February 26, 2010. The public OGC online form for change and feature requests as well as guidance for the submission is available at http://www.opengeospatial.org/standards/cr. Please note that anyone (i.e., OGC members and non-members, organizations as well as individuals) can answer this call. The next version of CityGML will be a minor revision of the standard to version 1.1. The anticipated release date will not be before autumn 2010. The main objective of this revision is to keep backwards compatibility with the current version 1.0 of CityGML. Change and feature requests resulting in a loss of backwards compatibility are welcome but will be postponed to a major revision of CityGML to version 2.0.

December 9, 2009

A new CityGML Standards Working Group (SWG) has been formed at the OGC Technical and Planning Committee Meetings in Mountain View, CA, USA. The purpose of the CityGML SWG is to work on the next minor and major revisions of the OpenGIS© CityGML Encoding Standard. The revisions will be based upon change and feature requests submitted by the public through the official OGC communication channels. OGC members are welcome to join and participate in the CityGML SWG. Please review the CityGML SWG Charter Document (OGC Doc. No. 09-139r3) for more information. According to the anticipated time schedule of the SWG, a first minor revision of CityGML to version 1.1 is expected to be released in autumn 2010 at the earliest. The main objective of this revision is to keep backwards compatibility with the current version 1.0 of CityGML.

Older news can be found in the News Archive

Web Resources

• Official CityGML Homepage: http://www.citygml.org (includes test datasets and software tools)
• Open Geospatial Consortium (OGC): http://www.opengeospatial.org
• OGC 3DIM Working Group: http://www.opengeospatial.org/projects/groups/3dimwg
• SIG 3D - NRW Homepage (in German only): http://www.ikg.uni-bonn.de/sig3d

IFC - Industry Foundation Classes

The IFC (Industry Foundation Classes) specification is a neutral data model to describe, exchange and share information typically used within the building and facility management industry sector. More Information can be found in the IFC Wiki.