Applying the 3d Gis Dilas to Archaeology and Cultural Heritage Projects – Requirements and First Results

The original aim of the 3D GIS project DILAS (Digital Landscape Server) was the efficient generation, management and visualisation of large 3D landscape and city models. Thus, the primary focus was placed on 3D objects with often generalised geometry and on medium to small scale representations. The result of the first project phase was an operational prototype of a 3D GIS based on an object-relational DBMS. This prototype system has since been commercialised and is now used in applications such as regional or city planning. Among the emerging application areas for 3D GIS are archaeology and the preservation of cultural heritage. This paper highlights some of the domain-specific requirements and illustrates how these requirements have been addressed in DILAS. The requirements include a strong support for object semantics, for complex object geometries and photo-realistic textures, for the integration of existing databases and for temporal aspects. 3D object support in DILAS is based on an object-oriented topological 3D data model. This model is automatically mapped between an object representation in Java and an XML representation which is stored in an object-relational DBMS (Oracle 9i). DILAS provides a rich semantic support at the object level and at the element level. DILAS is built on top of a spatial DBMS architecture (Oracle Spatial) and can make use of spatial indexing and querying functionality available in typical 2D GIS. This architecture has now been extended to support complex 3D objects, e.g. buildings consisting of their exterior hull and of different types of interior objects (rooms, hallways, caverns etc.). The following two projects served as case studies and test beds for the new features. In the first example DILAS was applied to the generation of a high-resolution, reality-based 3D model of the castle of Wildenstein, BL (Switzerland). The complex model incorporates the interior and exterior of the castle including its surroundings. The second project is the 3D reconstruction of the roman city of Augusta Raurica (Switzerland) and the modern city of Augst, which is partially built on top of the historic site. Both projects demonstrate the benefits of applying 3D GIS to archaeological and cultural heritage projects by integrating all required types of information into a single system environment. It is also shown, that a 3D GIS serves as an ideal platform for generating web-based 3D geoinformation services, in this case by using the high-performance viewer technology G-VISTA.