Preserving the Knowledge of the Past Through Virtual Visits: From 3D Laser Scanning to Virtual Reality Visualisation at the Istanbul Çatalca İnceğiz Caves

Cultural landscapes are those that are shaped through the combined forces of cultural and natural activity, typically over a long period that may reach back to historic and prehistoric times. Amongst these, the documenting, modelling and visualisation of cave landscapes have always been particularly important for scientific communities such as speleology. In the current state of the art, terrestrial laser scanning provides a level of documentation of objects whose accuracy cannot be achieved by conventional methods. In addition to the highly accurate metric and geometric information, visual information brings incredible richness to the presentation of data. Virtual reality (VR) allows individuals to immerse themselves within virtual environments to explore monuments and other cultural heritage sites up close. More and more, VR systems are available at lower prices and are not only limited to VR labs. In this paper, we present research on the generation of a virtual 3D model of the İnceğiz caves, located at the Çatalca district of Istanbul, Turkey, and its integration within the Unity 3D game engine. This project, carried out as a collaboration between BİMTAŞ, a company of the Greater Municipality of Istanbul, Turkey and the Photogrammetry & Laser Scanning Lab of the HafenCity University Hamburg, Germany, aimed at developing an immersive and interactive VR visualisation of the cave for the HTC Vive Pro VR system. The entire workflow, from data acquisition to VR visualisation, is described here in detail with particular emphasis given to the 3D modelling of the cave and its integration within a VR environment.