Pretended geometry – Concrete perception, Utilization of the surface of subdivision and the applied normal map in archaeological context: the case of the Great Termal Baths of Villa Adriana

The quality of architectural representation in real time interactive application, is one of the main themes of the current debate regarding the better ways to share datas between different scientific fields. Starting with the surveying operations by means of laser scanner technology, we can obtain point clouds, that are vary far from the real perception of architecture, but using color map texture (photogrammetry software) is possible to improve the appearance of low resolution models. On the contrary the metrical quality of decimated geomety becomes quite far from the original laser scan datas. Optimized UV reference systems associated to low-poly models can now be used not just as projection type for chromatic data, but also for new kind of texture called normal maps: this RGB images can achieve a new standard quality of digital models. Another aspect, very important for the optimization of 3D contents suitable for web based applications, is the level of detail (LOD). Complex meshes from 3D scanner, characterized by a high level of detail, cannot be used in web navigation