Dorffner, Lionel 
Up to now all mentioned possibilities are limited to interactions within a VRML scene. Concerning information systems 
it is also necessary to be able to control the scene from outside. This can be done using the EAI (External Authoring 
Interface) [Marrin C., 1997]. This interface allows programmers to establish a connection between a web page and an 
embedded VRML browser window, thus providing a possibility to manipulate the VRML scene depending on user 
requests on the web page [Zeisler Ph., 1999]. Using this possibility the interactivity is not limited any more to the purely 
VRML scene but also external systems, as for example data bases, can be connected. In this way, the VRML model can 
be used as kernel of an interactive spatial information system. [Landes S., 1999] 
7 CONCLUSIONS 
A world cultural heritage, like Hagia Sophia, is to be presented worldwide. Politicians, managers, scientists and 
interested non professional people should be able to get general and detailed information about such buildings or sites. 
Therefore an information system based on Web standards seems to be suitable. By using the 3D standard VRML photo- 
models can be made available over the internet to a great public without additional cost for a viewing software. Using 
the possibilities of linking additional information apart from geometry and texture to the photo-model complex spatial 
and thematic situations can be presented vividly. In this way, the photo-model becomes the kernel of an interactive 
spatial information system. 
The intended goal of this project is to document the whole building in an “Hagia-Sophia Information System” which 
will contain all information belonging to Hagia Sophia and shall be a useful guide for everyone. By using VRML we 
want to encourage the users accustomed to classical methods to develop themselves. This project proved the 
applicability of the new technology for studies of that kind.. 
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http://www.princeton.edu/-asce/const_95/const.html (31 March 2000) 
  
"Focus on the World", 2000. online magazine, History of Hagia Sophia. 
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http://www.vrml.org/W orkineGroups/vrml-eai/ExternalInterface.html. (31 March 2000) 
Matthews K., 1999. Great Buildings Online, Hagia Sophia. 
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UNESCO, 1985. The World Heritage List, Historic Areas of Istanbul. 
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Zeisler Ph., 1999. Nutzung von VRML für Informationssysteme basierend auf 3D-Photomodellen. Diploma thesis at the 
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International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B5. Amsterdam 2000. 179