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In combination with the dynamic visualisation this enables 
completely new possibilities for exploring and analysing the 
ancient city as well as potential conflicts between the 
archeological site and the modern city (Figure 11). 
5. CONCLUSION 
In the projects presented above it was possible to demonstrate 
the feasibility and benefits of applying a 3D GIS such as 
DILAS to cultural heritage projects. There are a number of 
advantages offered by the use of a 3D GIS for managing 
reality-based virtual 3D models. Among them are the 
possibilities of semantically structuring the data, of 3D 
geometry management and editing based on attribute predicates 
and the multi-user support which is an important aspect in 
major projects. But there are also some problems associated 
with creating 3D models of typical cultural heritage objects. 
The main problem is the efficient creation of 3D CAD models 
of the typically very complex non-planar geometry of such 
objects. The complexity of these real-world objects is generally 
not yet met by the capabilities of data exchange standards or 
visualisation tools such as VRML viewers. In the case of the 
castle of Wildenstein, for example, most facade and building 
parts have a very irregular geometry which would best be 
modelled using non-planar geometry. However, in order to 
ensure the usability of the results with standard tools and 
viewers, the geometric model had to be limited to planar 
shapes. For the acquisition of rooms and caverns laser scanning 
technology would be the ideal solution. Unfortunately, many of 
the processing tools available do not yet allow the full 
exploitation of the potential of this technology. For example, 
the software used had a poor or missing support for non-planar 
geometry, for constructing hidden objects, for object semantics, 
and for a selective data reduction. There are further challenges 
in the field of 3D viewer technologies such as a suitable indoor 
navigation and visualisation. Particularly in application areas 
such as archaeology and preservation of cultural heritage it is 
important to interactively and intuitively explore the interior of 
these objects. An additional problem is the visualisation of 
complex 3D objects with large amounts of texture data. A truly 
scalable 3D GIS such as DILAS provides the basis for handling 
such large reality-based 3D models in an integrated 
environment and for enabling new solutions for analysing and 
visualising such 3D databases. 
6. REFERENCES 
Burkhalter, I. and Fankhauser, M., 2000. Virtuelles 3D- 
Stadtmodell Augst und Rómerstadt Augusta Raurica. Diploma 
Thesis, FHBB Fachhochschule beider Basel, Muttenz 
Knabl, T., 2003. Weiterentwicklung des 3D-GIS DILAS — 
Automatische Texturierung von 3D-Objekten. Diploma Thesis, 
FHBB Fachhochschule beider Basel, Muttenz 
Nebiker, S., 1997. Spatial Raster Data Management — A Data- 
base Perspective. PhD Thesis, ETH Zürich, 179 pp. 
Nebiker, S., 2002a. Design and Implementation of the High- 
Performance 3D Digital Landscape Server 'DILAS', ISPRS, 
IGU, CIG - Joint International Symposium on Geospatial 
Theory, Processing and Applications, Ottawa, Canada. 
Nebiker, S., 2002b. Die 3D-Landschaftsservertechnologie dilas 
— Ein anwendungsorientiertes Forschungsprojekt, VPK Ver- 
messung, Kulturtechnik und Photogrammetrie, 3/02. 
Nebiker, S., 2002c. Multi-scale representations for scalable and 
dynamic 3D geoinformation services, Workshop on Data 
Generalisation and Data Mining, ISPRS Commission IV WG 
IV/3, Ottawa, Canada. 
Salathé, R., 2001. Digitales 3D-Stadtmodell Augusta Raurica. 
Civilian service, FHBB Fachhochschule beider Basel, Muttenz 
Wiist, T., 2002. Verwaltung von 3D-Stadtmodellen — Pilotstu- 
die «virtuelles Baugesuch». Diploma Thesis, FHBB Fachhoch- 
schule beider Basel, Muttenz 
7. ACKNOWLEDGEMENTS 
The authors would like to thank the Commission of Technology 
and Innovation (KTI) of the Swiss Federal Office for 
Professional Education and Technology (OPET) for the funding 
of the DILAS project. Thanks are also due to GEONOVA AG, 
the archeological team of Augusta Raurica and the state 
government of Basel-Land for their support and collaboration. 
    
  
   
  
   
  
  
  
  
  
  
  
  
  
  
   
   
  
  
    
  
   
   
   
   
  
   
   
   
  
  
  
  
  
  
  
  
  
  
  
  
   
  
  
  
   
  
  
   
  
  
   
  
   
  
  
  
   
  
  
    
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