2.3. Development history¶
Version 1 (2003 - 2007)
The development of the 3D City Database was always closely related to the development of the CityGML standard [KoGr2003]. It was started back in 2003 by Dr. Kolbe and Prof. Plümer at the Institute for Cartography and Geoinformation at University of Bonn. In the period from November 2003 to December 2005 the official virtual 3D city model of Berlin, commissioned by The Berlin Senate and Berlin Partner GmbH, was developed within a pilot project funded by the European Union [PGKS2005]. Since then, the model has been playing a central role in the three-dimensional spatial data infrastructure of Berlin and opened up a multitude of applications for the public and private sector alike. As an example the virtual city model is successfully used for presentation of the business location, its urban development combined with application related information to politicians, investors, and the public in order to support civic participation, provide access to decision-making content, assist in policy-formulation, and control implementation processes [DKLS2006].
The 3DCityDB was key in demonstrating the real world usage of CityGML to the Open Geospatial Consortium on the one hand, and the practical usability and versatility of CityGML to the city of Berlin on the other hand. This first development phase was carried out by University of Bonn in collaboration with the company lat/lon GmbH. Oracle Spatial was the only supported SDBMS in 3DCityDB versions 0.2 up to 1.3.
Version 2 (2006 - 2014)
Within the framework Europäische Fonds für regionale Entwicklung (EFRE II) the project Geodatenmanagement in der Berliner Verwaltung – Amtliches 3D-Stadtmodell für Berlin allowed for upgrading the official 3D city model based on the former CityGML specification draft 0.4.0 in the year 2007. The developments were carried out by the Institute for Geodesy und Geoinformation Science (IGG) of the Berlin University of Technology (where Kolbe became full professor for Geoinformation Science in 2006) on behalf of the Berliner Senatsverwaltung für Wirtschaft, Arbeit und Frauen and the Berlin Partner GmbH (former Wirtschaftsförderung Berlin International). The relational database model (3DCityDB versions 1.4 up to 1.8) was implemented and evaluated in cooperation with 3DGeo GmbH (later bought by Autodesk GmbH) in Potsdam. A special database interface for LandXPlorer was provided by 3DGeo / Autodesk. Later on, a first version of the Java based CityGML Importer/Exporter was developed [SNKK2009].
In August 2008, CityGML 1.0.0 became an adopted standard of the Open Geospatial Consortium (OGC). In the follow-up project Digitaler Gestaltplan Potsdam starting in 2010 the 3DCityDB version 2 (cf. [KKNS2009] and [NaSt2008]) was developed which brought support for all CityGML 1.0.0 feature types. The KML/COLLADA exporter was added as well as a ‘Matching’ plugin. This project was carried out by IGG of TU Berlin on behalf of and in collaboration with the company Virtual City Systems (VCS) in Berlin. In 2012, the developer team at TU Berlin received the Oracle Spatial Excellence Award for Education and Research from Oracle USA for our work on the 3DCityDB. Also in 2012, the 3DCityDB was ported to PostgreSQL/PostGIS by Felix Kunde, a master student from the University of Potsdam, who did his master thesis in collaboration with IGG [Kund2013].
In August 2012, CityGML 2.0.0 became an adopted standard of the Open Geospatial Consortium (OGC). In September 2012, Prof. Kolbe moved from IGG, TU Berlin to the Chair of Geoinformatics at Technische Universität München (TUM). The companies Virtual City Systems in Berlin and M.O.S.S. Computer Grafik Systeme GmbH in Taufkirchen (near Munich) have also been using the 3D City Database in their commercial projects for a number of years. In this context, the Chair of Geoinformatics at TUM and the companies Virtual City Systems and M.O.S.S. signed an official collaboration agreement on the joint further development of the 3DCityDB and its tools.
Version 3 (2013 - 2018)
The work on the new major release version 3.0.0 bringing support for CityGML 2.0 began in 2013 when Dr. Nagel finished his PhD and joined the company VCS. In version 3.3.0 the new 3D web client was being added. The webclient was developed by Zhihang Yao with contributions from Kanishk Chaturvedi and Son Nguyen. In 2015 Zhihang Yao and Kanishk Chaturvedi were awarded the first price in the ‘Best Students Contribution’ of the ‘Web3D city modeling competition’ under the annual ACM SIGGRAPH Web3D Conference for the 3DCityDB-Web-Map-Client.
Version 4 (since 2015)
The work on version 4 – especially the support of CityGML ADEs – began in 2015 in the course of the PhD work of Zhihang Yao. One part of his PhD thesis is focusing on the model transformation of CityGML ADEs onto spatial relational databases using pattern matching and graph transformation rules. Support of CityGML ADEs in the Importer/Exporter required a substantial rewriting of the citygml4j Java library, the Importer/Exporter and WFS source code performed by Dr. Nagel starting from 2016. Felix Kunde worked, among others, on performance improvements and restructuring of the PL/(pg)SQL scripts. Son Nguyen added support for mobile devices in the 3DCityDB-Web-Map-Client in 2017. Docker support was added by Bruno Willenborg in 2018. Starting from 2017 all partners worked on updating diverse functionalities, scripts, documentation, and on testing.
Version 5 (under development)
The next major version 5 of the 3DCityDB is intended to bring support for CityGML 3.0. CityGML 3.0 itself is a major update of the CityGML standard with many new features and capabilities, and is currently in the process for adoption as OGC standard.
Support for CityGML 3.0 will require substantial rework of the 3DCityDB database schema, scripts and all tools. We are planning to kick-off the development work in Q2 2021. Stay tuned on our GitHub page at https://github.com/3dcitydb for early results and prototypes. We are looking for feedback, discussions, and contributions from the 3DCityDB community.