The support of surgical interventions has long been in the focus of application-oriented augmented reality research. Modern methods of surgery, like minimally-invasive procedures, can benefit from the additional information visualization provided by augmented reality. The usability of medical augmented reality depends on a rendering scheme for virtual objects designed to generate easily and quickly understandable augmented views. One important factor for providing such an accessible reality augmentation is the correct handling of the occlusion of virtual objects by real scene elements. The usually large volumetric datasets used in medicine are ill-suited for use as phantom models for static occlusion handling. We present a simple and fast preprocessing pipeline for medical volume datasets which extracts their visual hull volume. The resulting, significantly simplified visual hull iso-surface is used for real-time static occlusion handling in our AR system, which is based on off-th...