A graphical system for interactive rendering of objects in an augmented reality scenery

We describe the rendering functions of the Augmented Reality System GEIST. GEIST is a 3D based narrative education system, an installation at the castle of Heidelberg, Germany, based on digital storytelling, GPS localization and interactive rendering. The rendering is interactive, as it is driven by user interaction, e.g. GPS position, head movement and line of sight as well as direct interaction (yes/no to questions of Virtual Characters).