The Mayan mascarón from Chilonché (Petén, Guatemala): New technologies for cultural heritage dissemination

this paper describes the procedures used to achieve the first 3D reconstruction of a mascarón, discovered in 03.13.2009 in the archaeological site of Chilonché (Guatemalan Petén). This is a typical architectural decoration of Mayan buildings that represents a mythic animal (half jaguar, half reptile) with approximated dimensions of 4×3 meters and characterized by its good level of conservation. The process started with data gathering (realized by an international team formed by Spanish, Guatemalan and Italian experts), carried out using a laser-scanner in an extremely narrow environment located in the substructure of the acropolis only accessible through the tunnel network (partially dug by looters). A high resolution polygonal B-Rep model has been obtained from the initial point cloud; furthermore high resolution pictures of the find have been projected on the model to add color information to the mesh. This extremely accurate and detailed model allows to study the topology of the original one and to replicate it using 3D printing technology. However, the excess of detail makes it unsuitable for real-time simulations. Using geometry simplification techniques, a low-poly model has been generated, integrating the geometrical information discarded from the original model through a normal map texture. The narrow and uncomfortable network of tunnels of the site creates very difficult conditions for local population and tourists to visit the mascarón. Using the low-poly model generated, and real-time simulation software, two kinds of visualization applications have been developed: a first one intended to study the original object using virtual reality devices, and a second one intended to allow the general public to visualize the reconstruction over an interactive web-based 3D real-time simulation.