Towards a Digital Practice of Historical Stone Carvings

Local traditional crafts in various parts of the world are being transformed by digitalization in tandem with broader social and economic changes. Mardin, a historical and cultural hub in southeast Anatolia, presents an exemplary case with its stone architecture. Whereas the number of skilled craftsmen is diminishing, digital fabrication ateliers are increasingly in demand in the city and rising in number. Training programs have already started integrating CNC milling-based techniques. However, despite the growing interest in adapting computational processes, how the craft knowledge is documented and conveyed to multiple actors for maintaining and even increasing the quality of workmanship is yet to be explored. We present a novel way to document carving procedures and to create an inventory of the 3D motifs using cross-sections as complements to front views. The research engages end-user participants of different backgrounds, such as stone cutting technologies and architecture, with little or no practical knowledge of digital manufacturing. The work focuses on a selection of motifs from the Syriac stone carving heritage in Mardin, the documentation of which is very limited. The proposed workflow begins with recording the surface depth and the variations in the cross-section using digital scans. In the second stage, we consider the potential subtractive transformations that result in the final form and reconstruct them as milling operations with a parametric and procedural modeling approach. Various milling processes are derived by relating the shapes to the available cutting tools and materials. The study contributes to creating the inventory of an engraving culture that has lasted for hundreds of years while developing a generally applicable and transferable knowledge base to increase its sharing and dissemination in the age of digitally supported production.