- © IGG
Cartographic generalization alters objects of a map, so that their shapes and arrangement leads to the best possible perception of the spatial situation. Today, three dimensional data plays an increasing role in map-like products, which is particularly true for 3D buildings in urban landscape models.
One of the most substantial elementary operations in cartographic generalization is the geometric simplification. For 2D building data, a number of approaches exist for generalizing ground plans while preserving object-specific characteristics. However, these concepts cannot be directly transferred to the three dimensional case. The same is true for the simplification algorithms from the field of computer graphics, which have been developed for highly detailed (triangular) mesh models, but have problems with rectangular shapes of the comparatively low detailed 3D building models. Therefore, generalization algorithms for the geometric simplification are developed in this field of research, which automatically generate lower detailed versions from given 3D building models, which reflect the global shape of the building as best as possible.
Only a certain level of detail can be reached by the simplification of single buildings until the models lose their specific shape characteristics. Further abstraction is only possible through the aggregation of building groups. By applying morphological operations, the generalization algorithms for simplification can be extended to close gaps between buildings and therefore achieve aggregation.
Keywords: Cartography, Generalization, Buildings, Three Dimensional, Algorithms
Contact:Prof. Dr.-Ing. Martin Kada
Dr.-Ing. Andreas Wichmann