The developed a virtual model of the cathedral on behalf of the Federal Ministry of Research and Technology. A very detailed model of the interior of the cathedral were developed. Special attractions represent the hexagonal cupola as well as the Piccolomini library. Beside a detail-faithful model complex elumination simulations provides for a photo-realistic representation. The project was first presented on the EXPO 2000 in Hannover. Later the project has been modified for presentation on Fraunhofer IGD’s and.