“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.

The Turkish metropolis of Istanbul is developing a 3D city model mainly aimed at urban planning, The data sources used so far include airborne Lidar, aerial images and 2D maps containing footprints of buildings. Everybody engaged in creating 3D models of large cities faces many issues, challenges and limitations, including excessive data storage requirements, the need for manual editing, incompleteness and other data quality problems. In this article, the authors share their experiences of creating models of the city of Istanbul at the level of detail (LOD) 2 and 3.

Determination and documentation are the basis of all studies in the context of conservation and sustainability of cultural heritage. Considering the number of historical and cultural properties and their deterioration status, the fastest and most accurate method of documentation is required to be used in these studies. With the development of technology, traditional documentation methods have been replaced by digitization which enables the acceleration of the whole process. 3D laser scanning technology is the most rapid, accurate (metric) and reliable method used in digitization studies of cultural properties / cultural heritage nowadays. By using laser point cloud data, 3D model of cultural properties can also be generated quickly and in detail as well as documentation and digital archiving. At this point, the integration of digital camera or 360° panoramic camera, which is very popular today, and point cloud data makes a significant contribution to further analyzes. This study expresses the 3D digitalization processes of the Suleymaniye Külliye (Mosque and Complex), which is included in the UNESCO World Heritage List. 3D model and VR applications, which are also outputs of the study, are discussed at the end part.

This paper describes the development of 3D database for Istanbul 3D city models. The schema is based on object-relational technology and also called spatially-enhanced relational database management system (SRDBMS). The 3D city models were generated based on LiDAR points cloud with other several typical GIS datasets like terrain, orthophoto, Point of Interests (POIs), and other attribute data. The database is based on PostGIS schema and CityGML schema (3DCityDB). Two major datasets, namely, terrain data (with several formats), and 3D city models were populated in the database. Terrain and attributes data retrieval are based on Web Feature Service (WFS) whereas 3D models were visualized via 3D Tiles format in Cesium platform. Two issues were also highlighted in the paper with respect to 3D attributes linkages and 3D complex objects.

This paper describes the generation of 3D city modelling of LoD2 and LoD3 buildings based on 3D point clouds data and other auxiliary data for Istanbul city, Turkey. The project is being undertaken by Istanbul Greater Municipality (IBB) since October 2012. The aim is to provide 3D information to the relevant city planning departments within IBB. The development of the 3D city model utilized several data acquisition techniques, software and computing tools as part of the methodology. The tools include from Riegl, TerraSolid, TerraScan, FME Workbench, MicroStation, and other visualization tools. The generated 3D city models illustrate how the high-resolution point clouds and 3D modelling play major role in such development. This paper also highlights several issues and challenges of the development, i.e. from data acquisition, processing of point clouds and the 3D modelling of buildings.