University of Southampton OCS (beta), CAA 2012

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Restitutions of architectural hypotheses in an archaeological 3D GIS
Eric Desjardin, Olivier Nocent, Dominique Pargny, Cyril de Runz

Last modified: 2011-12-21


Who never dreamed to travel through space and time? The convergence of GIS, archaeology, architecture, and 3D modeling allowed by the non-stop growing of computing power and network flow tends to have it feasible. Using Internet, we can nowadays view virtual 3D monument rebuilds in a 3S GIS. But by querying the prints of the past, the archaeological information is subject to imperfection (vagueness, uncertainty, lack…) that we need to collect, store and propagate in the construction of new results. In those processes, restitutions could be realized using a 3D GIS. In order to deal with it, we choose to work in the fuzzy set theory framework and confidence indices.

Therefore, the consideration of this imperfection in archaeological hypotheses in analyses, productions and restitutions should be studied. The search of realistic visual restitution leads us to present as a reality a more or less hypothesis. Therefore, we lose the richness of the confidence level that we have in our built or acquired knowledge. This raises the question of accessibility to the degree of validity of the provided visual information. Indeed, in order to face to question about the validity of realistic 3D representations of buildings, it seems interesting to provide a dynamic perception of knowledge with its quality.

Geospatial imperfect information visualization is an important issue. Several approaches were proposed in the literacy in the framework of 2D visualization: mapping, GIS, scientific data visualization, urbanism, archaeology, etc. Current approaches study the combination of the third dimension and time. Some visual paradigms may be mobilized for allowing their dynamic perception, adaptable according to the accepted truth level.

We propose to "wear glasses of reality" which according to the objective of the visualization may allow us to distinguish different level of hypotheses, for which we use several rendering technics according to the accepted level of truth. In order to permit this kind of process, our proposition consists in reversing the virtual reality paradigm: the more realistic the visualization, the more hypothetic the restitution (the more distant to the data). If we want to visualize the world with a high correspondence to the confidence we have in the knowledge, and if we know only few things, we use a “cartoon type” representation paradigm. To the opposite, if we would view the restitution through a realistic view, the information we perceive is a complete virtual construction. Some intermediary levels are proposed where the more confident data are the more realistic and the less confident are the more “cartoon”. We illustrate it on several archaeological restitutions with simulated confidence indices. This approach gives a good mean to interact with data restitution and their quality.



GIS 3D, archaeological hypothesis modeling, 3D modeling, uncertainty, information quality