Cyber City Modeller application

For today's post, a brief insight into one of the main commercial automatic/semi-automatic urban modelling packages today (with a variety of clients and projects, some listed below), the Cyber City Modeller application. The work for this application is based on research generated for a spin-off company of the Swiss Federal Institute of Technology Zurich (ETH Zurich), with the company itself founded in 2000.

Regarding its architecture; Cyber City Modeller is a C-based program which works for photogrammetric captured point clouds (x, y, z) based on semi-automatic extraction of objects from stereo-pairs of aerial (/satellite) images. For building creation the operator (or user) measures the essential points of the roof in a photogrammetric stereo model using an analytical plotter or a digital photogrammetric station (for example CC-VisualStar, SocketSet etc.). The software takes care of the automatic generation of planar roof faces with boundary polygons of the roof intersected with the DTM to get the facades (or alternatively cadastrial data can be projected back to the roof to obtain overhanging roofs). Realistic image textures for the roofs and the DTM are derived automatically from the aerial images and mapped onto the individual faces.

The method proposed is very flexible with respect to the required degree of detail in the generation, modelling and representation of the data. The number of objects that can be generated per time unit depends on the level of detail and the experience of each operator/user. The data is saved in the internal data management format, the V3D format (a text format), and can be exported to the formats of known CAD systems (e.g. DXF etc.) and also to real-time visualisation formats (e.g. FLT, VRML etc.). Finally, Cyber City Modeller consists of separate stand-alone modules for the generation (CC-Modeller) and editing (CC-Edit) of virtual 3D city models. Additionally, software for the texturing of facades with terrestrial images and for the automatic texturing of facades and roofs from aerial images is available (CC-Texture). To conclude, CC-VisualStar is also offered, a digital photogrammetric workstation with standard functions and additional specific functions for the capturing and updating of 3D city models.

Some resulting models from the system are shown earlier on in this post and other models include visualisations of Hamburg, the Zurich airport, the Los Angeles International airport, Bonn, Las Vegas, Vienna landmarks, Munich and many others. More information on Cyber City Modeller, its components, architecture, clients and also a list of the numerous major academic conference and journal publications generated from the work can be found at http://www.cybercity.tv/ and are all well worth exploring...