One of the simplest methods to construct a 3D city model is to extrude building footprints to obtain “block-shaped" polyhedra representing buildings. While the method is well-known and easy to implement, if the 2D topological relationships between the footprints are not taken into account, the resulting 3D city models will not necessarily be topologically consistent (i.e. primitives shared by 3D buildings will be duplicated and/or intersect each other). As a result, the model will be of little use for most applications, besides visualisation that is. We present a new procedure to construct topologically consistent 3D city models by extrusion of building footprints. It takes as input a topologically consistent dataset in 2D, and can output different formats, including for instance CityGML.
This dataset is an example of a topological consistent 3D City model of the Campus of Delft University of Technology produced by this new procedure