Katerina MANIA / Lemonia RAGIA
(Technical University of Crete, Chania, Greece)

Keywords: semantic modeling, reconstruction, 3D Visualization

Abstract:
This paper presents a flexible geodetic measurement procedure targeting the photorealistic and interactive documentation and reconstruction of an archeological monument in Crete, Greece. We present an approach based on the speed, range and correctness combined of a total station’s measurements of geo-referenced points producing a fully interactive and photo realistically lit geometric mesh of a Venetian building named ‘Neoria’ by the old harbour in Chania, Crete, Greece. Our task is to fully explore the potential of computer graphic techniques taking as input geodetic measurements and modeling the archaeological monument in 3D enriching it with additional thematic information. The building named ‘Neoria’ was completed in 1599, involving seven continuous domes and used for ship repair during the winter time. Employing a modern total station results in high accuracy point measurements and quick and efficient spatial data acquisition. The proposed framework creates a detailed 3D geometric model of the monument from the terrestrial points. It subsequently lights the geometric mesh utilizing modern global illumination algorithms and provides advanced interactive functionalities to the user who can interactively manipulate as well as navigate the geometric model. The expert user receives information in relation to the maintenance of the facades of the archaeological monument. For example, based on adequate point acquisition, the user can determine the position and extent of erosions in the material surfaces, whether the surface is smooth or includes bumps, whether there are cleaved and damaged pieces or cracks and of which size, which subsequently  require full restoration. It can also be investigated whether the edges of the walls and roof are vertically aligned or whether there are related discrepancies. The goal of the proposed framework is to offer to the expert user an interactive tool which will help to determine whether the building needs maintenance and the severity of it.