This book contains the scientific papers presented at the SthEUROGRAPHICS Workshop on Virtual Environments '99, which st st was held in Vienna May 31 and June 1 . It was organized by the Institute of Computer Graphics of the Vienna University of Technology together with the Austrian Academy of Sciences and EUROGRAPHICS. The workshop brought together scientists from all over the world to present and discuss the latest scientific advances in the field of Virtual Environments. 31 papers where submitted for reviewing and 18 where selected to be presented at the workshop. Most of the top research institutions working in the area submitted papers and presented their latest results. These presentations were complemented by invited lectures from Stephen Feiner and Ron Azuma, two key researchers in the area of Augmented Reality. The book gives a good overview of the state of the art in Augmented Reality and Virtual Environment research. The special focus of the Workshop was Augmented Reality, reflecting a noticeable strong trend in the field of Virtual Environments. Augmented Reality tries to enrich real environments with virtual objects rather than replacing the real world with a virtual world. The main challenges include real time rendering, tracking, registration and occlusion of real and virtual objects, shading and lighting interaction, and interaction techniques in augmented environments. These problems are addressed by new research results documented in this book. Besides Augmented Reality, the papers collected here also address levels of detail, distributed environments, systems and applications, and interaction techniques.