COMBINATION OF VIRTUAL TOURS, 3D MODEL AND DIGITAL DATA IN A 3D ARCHAEOLOGICAL KNOWLEDGE AND INFORMATION SYSTEM

The site of the Engelbourg ruined castle in Thann, Alsace, France, has been for some years the object of all the attention of the city, which is the owner, and also of partners like historians and archaeologists who are in charge of its study. The valuation of the site is one of the main objective, as well as its conservation and its knowledge. The aim of this project is to use the environment of the virtual tour viewer as new base for an Archaeological Knowledge and Information System (AKIS). With available development tools we add functionalities in particular through diverse scripts that convert the viewer into a real 3D interface. By beginning with a first virtual tour that contains about fifteen panoramic images, the site of about 150 times 150 meters can be completely documented by offering the user a real interactivity and that makes visualization very concrete, almost lively. After the choice of pertinent points of view, panoramic images were realized. For the documentation, other sets of images were acquired at various seasons and climate conditions, which allow documenting the site in different environments and states of vegetation. The final virtual tour was deducted from them. The initial 3D model of the castle, which is virtual too, was also joined in the form of panoramic images for completing the understanding of the site. A variety of types of hotspots were used to connect the whole digital documentation to the site, including videos (as reports during the acquisition phases, during the restoration works, during the excavations, etc.), digital georeferenced documents (archaeological reports on the various constituent elements of the castle, interpretation of the excavations and the searches, description of the sets of collected objects, etc.). The completely personalized interface of the system allows either to switch from a panoramic image to another one, which is the classic case of the virtual tours, or to go from a panoramic photographic image to a panoramic virtual image. It also allows visualizing, in inlay, digital data, like ancient or recent plans, cross sections, descriptions, explanatory videos, sound comments, etc. This project has lead to very convincing results, that were validated by the historians and the archaeologists who have now an interactive tool, disseminated through internet, allowing at the same time to visit virtually the castle, but also to query the system which sends back localized information. The various levels of understanding and set up details, allow an approach of first level for broad Internet users, but also a deeper approach for a group of scientists who are associated to the development of the ruins of the castle and its environment.