The SIG3D is a major player in the OGC standardization process for an interoperable semantic model for 3D buildings and landscape. For this purpose CityGML was developed by the SIG3D and standardized by the OGC (current version 1.0.0). The SIG3D still contributes to further developments and extensions of CityGML like the CityGML Noise ADE. CityGML is based entirely on OGC and ISO TC 211 standards (GML, ...), and has been successfully tested in OWS 4 testbed.
The CityGML standard is currently supported as an exchange format for semantic building models in various software systems, especially GIS and CAD systems.
Various large scale 3D city models (including landscape and buildings) were generated by public and private members of the SIG3D (e.g. North Rhine-Westphalia, Berlin) on the basis of CityGML.
These city models are completely database driven and the exchange of spatial data is realized thru OGC web services.
The SIG3D was also involved in the testing process of INSPIRE Annex I specifications, mandated by the German SDI GDI-DE