CyberCity Modeler, a tool for interactive 3-D city model generation

Cybercity Modeler (CC-Modeler) is a semi-automated generator for 3-D objects of built-up environments. Given the primary data as point clouds measured on Analytical Plotters or Digital Stations, CC-Modeler presents a new method for fitting planar structures to the measured sets of point clouds. While this topology generator has been originally designed to model buildings, it can also be used for other objects, which may be approximated by polyhedron surfaces. We have used it so far for roads, rivers, parking lots, ships, etc. CC-Modeler is a generic topology generator. The problem of fitting planar faces to point clouds is treated as a Consistent Labeling problem, which is solved by probabilistic relaxation. Once the faces are defined and the related points are determined, a simultaneous least squares adjustment is applied in order to fit the faces jointly to the given measurements in an optimal way. We first present the processing flow of CC-Modeler. Then, the algorithm of structuring the 3-D point data is outlined. Finally, we show the results of several data sets that have been produced with CC-Modeler. Also, reference is made to a new concept for a spatial information system (CC-SIS, CyberCity Spatial Information System)which is currently under development.