Realization of a Framework for the Development of 3D Geographic Information Systems

Due to the rapid pace of progress in hardware, there is an increasing demand for and use of Geographic Information Systems (GIS) in a growing number of areas. GIS will certainly be required especially in three-dimensional applications in the near future. But mostly GIS applications that require the support of three dimensions are so-called 2.5D-GIS because the height information is handled merely as an attribute to support 3D visualizations. Our understanding of 3D-GIS is that the third dimension must be generally supported, i.e. that inquiries about the geometry and topology in all dimensions must also be supported. To support the realization of such a 3D-GIS a framework must cover the following areas: the object management in the form of lists, trees, hash-tables, etc.; the task of modeling and analyzing the spatial objects in a 3D data model and the construction of a graphical user interface (GUI). The use of object-oriented concepts enhances the reusability, maintenance, and, most importantly, the expansibility of the framework. Expansibility means that the framework can grow according to the requirements and experiences emerging during the course of a project. Therefore a well-defined architecture is chosen for the framework.