When script engravings reveal a semantic link between the conceptual and the spatial dimensions of a monument: The case of the tomb of Emperor Qianlong

Like most Chinese imperial tombs, the tomb of Emperor Qianlong consists of a suite of four rooms forming a underground space of 372 m2. Its originality lies in the inscriptions which are engraved on the walls and vaults and exclusively in Tibetan (30,000 characters) and Lantsa (600 characters). In the project we present here, all engravings were digitized and a large part of them have been identified. Their identification has highlighted the idea which was certainly at the base of ornamental program of the Qianlong\´s tomb: the choice of texts and their particular arrangement was used to virtually reconstruct a "stupa" : a Buddhist funerary monument. So the study and representation of script engravings and iconography of the tomb opened the general issue of finding an original solution to explain, from a visual and semantic point of view, the relationship of two parallel dimensions. On the one hand, the description of the morphology of the tomb through the spatial structure of geometric entities in a 3D model (collection of architectural forms and spatial relationships), on the other hand, the description of knowledge related to the Tibetan funeral rituals (abstract concepts and semantic relations). The formalized and represented textual and graphics data become accessible within an analytical support (information system) allowing to explore the relationship between the conceptual and spatial dimensions of the tomb through three interactive devices interconnected: a real-time 3D scene for exploring the physical space, a dynamic graph for navigating within a network of interconnected concepts, an graphic schema displaying the theoretical position of each conceptual and spatial entity within the representation of a virtual stupa.