Photorealistic Real-Time Visualization of Cultural Heritage: A Case Study of Friedrichsburg Castle in Germany

Abstract

This paper presents a novel highly immersive and interactive VR (virtual reality) installation targeted on photorealistic real-time visualization. Although applicable to many other scenarios, this work is focused primarily on virtual reconstructions in the context of cultural heritage projects. We address two shortcomings in most of the current virtual reconstructions, namely interactivity and realism. On the one hand many of them are presented either as a movie or using semi-interactive techniques. In both cases the imagery is pre-rendered and therefore the visualization is lacking interactivity. On the other hand interactive real-time presentations often are neither intuitive to navigate nor visually pleasant. We extended a real-time rendering software based on global illumination to adapt to the special needs of the visualization of virtual scenes that stem from the field of cultural heritage. A HDR (high dynamic range) daylight simulation was developed in conjunction with techniques and algorithms to significantly speed up the calculation time and increase the visual quality of the scene. To account for the different lighting situations encountered in the visualization of indoor and outdoor scenes, we developed a high dynamic range rendering pipeline that uses a dynamic tone mapping algorithm similar to human vision. To provide interactive access to the high quality 3D model even for unskilled users, we developed a very intuitive user interface based on a simple touchscreen for navigating the virtual scene. The combination of the real-time presentation of the photorealistic reconstruction and the intuitive navigation interface leads to a highly immersive and interactive VR installation. Since we are currently working on a virtual reconstruction of a Renaissance castle located in southern Germany, we will therefore use this reconstruction as a case study to present the developed features and to prove their relevance and usefulness. The virtual reconstruction is displayed using our VR installation and will be accessible to the public in the State Museum of Hohenzollern by August 2007