VIRTUALISING AN OTTOMAN FORTRESS – LASER SCANNING AND 3D MODELLING FOR THE DEVELOPMENT OF AN INTERACTIVE, IMMERSIVE VIRTUAL REALITY APPLICATION

“A picture is worth a thousand words”: a famous quote about knowledge dissemination but also literally true. The documentation of cultural heritage (CH) monuments is carried out by measurements and photos and stored in 3d models – not by textual information alone. So what could be a more straightforward way to inform the public about CH than visual information? This approach can be extended not only by providing static images or videos from predefined angles but by giving the user the opportunity to interactively explore the virtual representation and interact with the scene. Recent advances in contemporary Virtual Reality (VR) have made it available to more people as prices have dropped. New devices have entered the market so that VR is not limited to VR labs, but is available even at home. With modern head-mounted displays the user can immerse himself in the virtual CH monument to explore and interact with it. Game engines offer tools for rapid development of interactions and help to produce visually appealing worlds.In this paper is presented the generation of a virtual 3D model of Rumeli Hisarı, an Ottoman fortress at the Bosporus in Istanbul, Turkey (Fig. 1) and its processing for data integration into the game engine Unity. The project has been carried out as a co-operation between BİMTAŞ, a company of the Greater Municipality of Istanbul, Turkey and the Photogrammetry & Laser Scanning Lab of the HafenCity University Hamburg, Germany with the aim of a VR application for an immersive and interactive visualisation of the fortress using the VR system HTC Vive. The workflow from data acquisition to VR visualisation, including the necessary programming for navigation, is described. Furthermore, the possible use (including simultaneous multiple users environments) of such a VR visualisation for a CH monument is discussed.