From CAD to GIS to BIM to where? Archaeological documentation in 3D

Abstract

The gradual shift from Computer-Aided Design (CAD) based documentation to Geographic Information Systems (GIS), and more recently also to Building Information Modelling (BIM) approaches, showcases the necessity of effectively modelling the excavation documentation process in 3D. Although the use of each technology results in target-specific documentation approaches and distinct geometric data types, our review recognises their complementary usage in different stages of the spatial modelling procedure (e.g., data capture, topology, semantic tagging). In this contribution, we aim to contextualise our experience in excavation documentation and discuss some of the evolving traits and parameters of these platforms. Relevant examples are taken from work in the context of the Thessaloniki Toumba and the Paliambela Kolindros excavation projects, as well as the Acropolis Restoration Service database visualisation platform. These are discussed in their historical context and in conjunction with relevant research examples. The retrospective consideration of different methodologies and available workflows in CAD, GIS and BIM has the potential to: 1) detect the limitations and potentials in each application category, 2) provide a more inclusive understanding of the graphical requirements for representing and handling excavation features in 3D and 3) to inform current attempts towards 3D intra-site documentation and 3D functionality. Our review indicates that CAD tools remain relevant to geometric modelling, GIS continue to play an integral role in combining and analysing cross-scale graphical, thematic and temporal information, while BIM maintains its usability in the structural division of standing architecture, conservation assessment and reconstruction. Their growing convergence and interoperability may provide novel opportunities for the combined exploitation of their individual functionality.