Model and experience. Measuring deformations of rupestrian architectures in the area of Göreme

The tufa limestone that characterizes much of Cappadocia is a sensitive material to be shaped both by wind erosion and by man's tools. For centuries these parallel actions have been producing a highly dynamic landscape, which changes in real time and in which what is artificial is hardly distinguishable from what is properly natural. Rock-cut settlements often demonstrate precise spatial and stylistic intentions. Obviously, the constructive precision of these architectures is a function of both specific historical events and inconstant technical skills of the builders. Nevertheless, most of these "full-scale models" referencing to traditional Byzantine architectures in XX century were usually perceived and represented as regular structures by scholars such as Jerphanion, Thierry, and Rodley. The surveys conducted with automatic photogrammetry in recent years have revealed that the most of these rock-cut environments are very irregular shaped. As part of a national research, the authors have participated in the survey and the digital documentation of some monumental sites in Goreme, using primarily laser-scanner and numeric models to produce faithful and incorruptible models of the sites. A further possible application of these models is to relate the true form of rooms with the way people perceive and experience them. This paper presents the results of a geometric study in order to define the range of such deformations compared to supposed regular models behind them and measure the "threshold" of their perception. Even if the sensitiveness to space is largely a cultural inconstant phenomenon, as a corollary, this paper aims at contributing to understanding some of the possible original intents of their builders.