Abstract
My Sơn Sanctuary comprehends several ancient Hindu temples and is the most foremost heritage site of this nature in Vietnam. Part of the complex is today seriously damaged and needs restoration works. The temple G1 addressed in this work represents a pilot case to establish a workflow for both documentation and conservation purposes. Both aims required as primary need the 3-D digital reconstruction of the object. The current conditions of the temple and the presence of inhomogeneous textures on its walls made the reconstruction process quite complex. Due to the impossibility of using a terrestrial laser scanning for economic and environmental problems, a low-cost photogrammetric solution was adopted to carry out data acquisition, image orientation and 3-D reconstruction of the temple. The small cost of the camera (a Nikon D80) and the user-friendliness of the SW PhotoModeler 6 Scanner allowed also people not fully skilled in photogrammetry to give an important contribution to this project. In addition, an algorithm for automatic orientation of marker-less image sequences through a Structure and Motion strategy was used to check its applicability for further surveys, in order to speed up and to make automatic the process. The paper will also shows different types of final products that can be yielded and delivered (3-D vector model, orthophotos, anagliphic images for 3-D stereo visualization)