Conservation of Ancient Sites on the Silk Road: 2nd International Conference on the Conservation of Grotto Sites, Mogao Grottoes - Dunhuang (China), 28/6-3/7/2004 Applications of High-Resolution 3D Imaging to the Recording and Conservation of Ancient Crypt and Grotto Sites J. M. Taylor, J.-A. Beraldin, M. Picard, S.F. El-Hakim, G. Godin 1 V. Valzano, A. Bandiera 2 Abstract: The National Research Council of Canada (NRC) has collaborated with numerous Canadian and international heritage institutions on the development of a complete suite of 3D imaging technologies for archival quality imaging, analysis and display of 3D models of museum objects and heritage sites including ancient crypt and grottos. The technology includes high-resolution laser scanner systems for recording museum objects and heritage sites, software for modeling and display of the 3D models as well as for examination, comparison and searching of 3D data. For example, we have collaborated on projects to prepare a 3D VR tour of the Tomb of Tutankhamun, for recording accurate geometric 3D models the Tomb of St. James in Jerusalem and of the Dazu (Bei Shan) Buddhist rock carvings and sculptures site in China, as well as for recording an archival quality photo-realistic 3D digital model of the Byzantine crypt of Santa Cristina in Italy. This paper presents an overview of this technology related to its applications for recording ancient crypt and grotto sites. Keywords: 3D imaging; heritage recording; conservation documentation; shape and appearance modeling; virtual environments. Introduction: The accurate recording of ancient crypt and grotto sites is a challenging task. The sites have either formed naturally or been carved from the surrounding rock and typically the walls, floors, and ceilings have an irregular surface shape and the paintings follow the contours of the rock surface over large areas. These features—particularly the shape of the rock surface—are difficult to record, measure, compare and display using conventional photographic and conservation recording techniques. Dating back to 1984, the National Research Council of Canada (NRC) has collaborated with numerous Canadian and international museums and heritage institutions as well as with industrial partners on the development of a complete suite of 3D imaging technology tools for a wide range of museum and heritage recording applications. In the process, the staff has developed a great deal of field expertise on the imaging of museum collections as well as archaeological and architectural sites. High-resolution 3D models of museum objects and heritage sites contain a wealth of information that can be examined and analyzed for a variety of conservation, research, and display applications. For example, in the case of a site that must be closed or subjected to limited access for conservation reasons, an immersive 3D virtual reality theater can be used to enable visitors to “virtually” visit the site. Researchers can magnify or zoom in on a 3D model to examine, measure, and compare fine surface details for signs of deterioration or to examine tool mark or brush stroke features. 1 Institute for Information Technology, National Research Council 2 SIBA Coordination, University of Lecce