Implementation of Elementary Geometric Database Operations for a 3d-gis

We report on a preliminary study carried out for the development of a 3D-GIS, which is supposed to manage geoscientific data of the Lower Rhine Embayment. The implementation of geometric 3D-operations is fundamental for 3D-GIS. Here we present the realization of an extensible geometric library implemented within an object oriented prototype database kernel system. The spatial representation used for the 3D-objects are extended simplicial complexes. First runtime tests in the database kernel with geometric operations on geological layers and faults are presented. Furthermore, we describe optimizations of the algorithms based on the direct support of the internal topology of the extended complexes.