Towards Virtual Reality GIS

Due to the rapid developments in the field of computer graphics tools allowing for the real time visualisation of complex 3D data are becoming available also for standard applications. One example is the visualisation of urban landscapes within GIS. This type of application additionally profits from the fact, that meanwhile the required urban models can be collected area covering and efficiently based on aerial data like stereo images or LIDAR. Nevertheless, the requirements for data collection are still increasing due to the current spread of visualisation applications. One example is the generation of realistic visualisations from pedestrian viewpoints. In such a scenario the viewpoint restrictions of airborne platforms do not allow for the collection of sufficient image texture and geometric detail for the facades of the buildings. Since this information is required to guarantee a good visual appearance of the urban model from pedestrian perspectives, additional data has to be provided. Thus, terrestrial sensors have to be applied. Frequently, virtual reality presentations of urban areas also require the integration of additional objects representing vegetation and street regions. Within the paper these data requirements for virtual GIS will be discussed. Additionally, the potential of integrating tools from computer graphics for this type of application will be demonstrated. As an example, programmable graphics hardware is used to provide a time efficient solution of complex geometric tasks to be solved during texture mapping of 3D building models.