3DCG reconstitution and virtual reality of UNESCO world heritage in danger: The Citadel of Bam

This paper provides a report of a research project on virtual revival of the Citadel of Bam, a UNESCO world heritage site in danger that was destroyed in an earthquake in 2003. The simulation of damaged buildings that lies along the primary axes of the citadel and 3-D reconstitution using state-of-the-art 3DCG tools are presented. The key approach to 3-D modeling of the destroyed buildings is complementary usage of heterogeneous data such as 2-D maps, photos, cartography maps, and sketches in collaboration between different teams. As the basic 2-D maps had error, analytic and comparative research is conducted on diverse data resources to create a knowledge-base for the 3DCG restoration of the site. The process of modeling is completed with regard to the complicated and curved mud brick buildings with traditional architectural details. For this purpose proper functions of the tools is selected and in some cases different tools are used. The modeling is done by linking the component with their semantic by a metadata-based layer naming process. The tasks of evaluating the historical, architectural, and technical details of the 3-D buildings are done in parallel with the modeling by a team of CG and architecture experts in order to increase the precision of the 3DCG reconstitution so that it can be used as a reference for the physical restoration. The first trial version of virtual reality demonstration of the main axes of the Citadel of Bam is described. The paper concludes with proposals to enhance the process of simulation and also to open the restricted views of the virtual reconstitution on Internet.