Virtual reality (VR) is a multidisciplinary area of research aimed at interactive human¿computer-mediated simulations of artificial environments. An important aspect of VR-based systems is the stimulation of the human senses ¿ usually sight, sound, and touch ¿ in such a way that a user feels a sense of presence in the virtual environment. Sometimes it is important to combine real and virtual objects in the same real or virtual environment. This approach is often referred to as augmented reality (AR), when virtual objects are integrated into a real environment. Typical VR applications include simulation, training, scientific visualization, and entertainment, whereas typical AR applications include computer-aided manufacturing or maintenance and computer-aided surgery or medicine.This book comprises a collection of research and position papers presented at Dagstuhl Seminar 13241 on Virtual Realities, held at Schloss Dagstuhl, Germany, in June 2013. The 13 papers in this volume were carefully reviewed and selected from 18 submissions. They are organized in topical sections on: VR environments; interactions and user experience; virtual humans; and tele-existence.

Features papers from leading international experts and promising young researchers, discussing current VR and AR challenges and future directions

VR Environments.- Live Will Never Be the Same! How Broadcasting Might Influence the Acceptance and Widespread Usage of Augumented Reality.- Four Metamorphosis States in a Distributed Virtual (TV) Studio: Human, Cyborg, Avatar, and Bot - Markerless Tracking and Feedback for Realtime Animation Control.- VELOS - A VR Environment for Ship Applications: Current Status and Planned Extensions.- Underwater Mixed Environments.- Interaction and User Experience A Critical Analysis of Human-Subject Experiments in Virtual Reality and 3D User Interfaces.- Mobile Devices for Virtual Reality Interaction. A Survey of Techniques and Metaphors.- Hand Pose Recognition - Overview and Current Research.- Virtual Humans.Applications of Avatar Mediated Interaction to Teaching, TrainingJob Skills and Wellness.- VR-Assisted Physical Rehabilitation: Adapting to the Needs of Therapists and Patients.- Hierarchical Method for Segmentation by Classification of Motion Capture Data.- Content Creation and Authoring Challenges for Virtual Environments: From User Interfaces to Autonomous Virtual Characters.- Tele-Existence.- Technical Report: Exploring Human Surrogate Characteristics.- Telexistence: Past, Present, and Future.