20 March 2007: With the new CityGML, the three dimensional data contains real intelligence and is now a reliable application for real-life deployment in telecommunications, city planning, disaster recovery, noise mapping, simulators and vehicle navigation. During the Oracle Spatial SIG Meeting in Reading last month, Ian Painter of Snowflake Software presented how GO Publisher has been used in the Open Geospatial Consortium OWS-4 Test Bed to deploy CityGML via Web Feature Services.
Until recently, virtual 3D city models only consisted of façade graphics – providing an appealing visualization of the surroundings but no further information. Missing are the details on the buildings themselves – the semantic aspects with information on the storeys, owners, components and even construction year and status. Typically, these models are also based on proprietary exchange formats. The industry now recognises a need for an open standard to address these issues.
CityGML – originating from the SIG 3D of GeoData Infrastructure (GDI) NRW – is a GML3 application schema designed for multi functional city modelling. It is unique in that it covers the four most important aspects of virtual 3D city models: Geometry, Semantics, Topology and Appearance. CityGML offers coherent spatial and semantic modelling – providing an ideal balance between simplicity and the need for structure.
Painter presented how Snowflake connected its GO Publisher WFS (Web Feature Server) to numerous Oracle databases – each using different 3D relational models – which it then published to CityGML. The presentation also highlighted the importance of organisations being able to store and manage 3D in a relational model of their choice. CityGML can then be utilised as a wrapper around these models to create a unified open standard interface for the exchange of city models.
Snowflake Software also played a role in the Open Geospatial Consortium OWS-4 Test Bed where GO Publisher WFS was deployed to publish CityGML and 3D TIN’s over the internet to CAD and BIM clients in both North America and Germany.
“GO Publisher’s ability to schema translate from any relational model to any given GML application schema is proven in the 2D world,” explained Painter, “It is great to demonstrate to the Oracle Spatial community how this same technology can be put to work on some very complex 3D models, from helicopters to full architectural 3D walkthroughs.”
Further information can be found in “Extending 2D Interoperability Frameworks to 3D” – A White Paper at: www.snowflakesoftware.co.uk/news/papers.htm.