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What is CityGML

What is CityGML?

CityGML is a common information model and XML-based encoding for the representation, storage, and exchange of virtual 3D city and landscape models. CityGML provides a standard model and mechanism for describing 3D objects with respect to their geometry, topology, semantics and appearance, and defines five different levels of detail. Included are also generalization hierarchies between thematic classes, aggregations, relations between objects, and spatial properties. CityGML is highly scalable and datasets can include different urban entities supporting the general trend toward modeling not only individual buildings but also whole sites, districts, cities, regions, and countries.

CityGML provides much more than 3D content for visualization by diverse applications. It allows users to share virtual 3D city and landscape models for sophisticated analysis and display tasks in application domains such as environmental simulations, energy demand estimations, city lifecycle management, urban facility management, real estate appraisal, disaster management, pedestrian navigation, robotics, urban data mining, and location based marketing.

CityGML has been implemented in many software solutions and is in use in many projects around the world. In National Spatial Data Infrastructure programs in the Netherlands, Germany, France, Malaysia, Abu Dhabi and other countries, CityGML provides an important platform for the transition from 2D to 3D data. It also plays an important role in bridging Urban Information Models with Building Information Models (BIM) to improve interoperability among information systems used in the design, construction, ownership and operation of buildings and capital projects.

CityGML is realised as an open data model is implemented as an application schema for the Geography Markup Language 3 (GML3), the extendible international standard for spatial data exchange issued by the Open Geospatial Consortium (OGC) and the ISO TC211. Because CityGML is based on GML, it can be used with the whole family of GML compatible OGC web services for data accessing, processing, and cataloging like the Web Feature Service, Web Processing Service, and the Catalog Service. CityGML is an open standard that can be used free of charge.

Created and maintained by Thomas H. Kolbe
Last update: 2012-04-24