Extraction of constructive geometries from numerical models. The city walls in the Hattusa Gorge

The paper presents the results of research conducted in the gorge area of the archaeological site of Hattusa in Anatolia, Turkey (listed as a UNESCO World Heritage Site in 1986), aimed at developing a survey methodology and three-dimensional data management for the identification of traces of ancient walls on the rocks and their analysis within a digital simulation space. Within the area, digitization procedures were carried out by means of laser scanners, drone and ground photogrammetric systems, handy scanners, and total stations. All data produced were referenced and aligned by topographic points, in order to set up the models for the subsequent segmentation and spatial analysis phases. The traces, mapped and analyzed in relationship to the construction techniques of the Hittites, made it possible to redraw the possible trajectories and forms of the structures, addressing the complex issue of the gorge crossing of the city's fortification system. This approach emphasized the key role of three-dimensional surveying techniques and representation of numerical models in relation to data visualization procedures. The segmentation of the models and sequence of the signs allowed a new use of spatial data beyond the limits of a representation exclusively rendered by means of point clouds or continuous meshes, providing new solutions to the interpretation of an area of Hattusa that is still poorly studied due to the considerable complexity of the places.