Alphanumeric text entry is a challenge for Virtual Reality (VR) applications. VR enables new capabilities, impossible in the real world, such as an unobstructed view of the keyboard, without occlusion by the user's physical hands. Several hand representations have been proposed for typing in VR on standard physical keyboards. However, to date, these hand representations have not been compared regarding their performance and effects on presence for VR text entry. Our work addresses this gap by comparing existing hand representations with minimalistic fingertip visualization. We study the effects of four hand representations (no hand representation, inverse kinematic model, fingertip visualization using spheres and video inlay) on typing in VR using a standard physical keyboard with 24 participants. We found that the fingertip visualization and video inlay both resulted in statistically significant lower text entry error rates compared to no hand or inverse kinematic model representations. We found no statistical differences in text entry speed.
Over the last 20 years research has been done on the question of how egocentric distances, i.e., the subjectively reported distance from a human observer to an object, are perceived in virtual environments. This review surveys the existing literature on empirical user studies on this topic. In summary, there is a mean estimation of egocentric distances in virtual environments of about 74p of the modeled distances. Many factors possibly influencing distance estimates were reported in the literature. We arranged these factors into four groups, namely measurement methods, technical factors, compositional factors, and human factors. The research on these factors is summarized, conclusions are drawn, and promising areas for future research are outlined. Foreword. Preface. I. FOUNDATIONS OF 3D USER INTERFACES . 1. Introduction to 3D User Interfaces. What Are 3D User Interfaces? Why 3D User Interfaces? Terminology. Application Areas. Conclusion. 2. 3D User Interfaces: History and Roadmap. History of 3D UIs. Roadmap to 3D UIs. Scope of This Book. Conclusion. II. Hardware Technologies for 3D User Interfaces. 3. 3D User Interface Output Hardware. Introduction. Visual Displays. Auditory Displays. Haptic Displays. Design Guidelines: Choosing Output Devices for 3D User Interfaces. Conclusion. 4. 3D User Interface Input Hardware. Introduction. Desktop Input Devices. Tracking Devices. 3D Mice. Special-Purpose Input Devices. Direct Human Input. Home-Brewed Input Devices. Choosing Input Devices for 3D Interfaces. III. 3D INTERACTION TECHNIQUES. 5. Selection and Manipulation. Introduction. 3D Manipulation Tasks. Manipulation Techniques and Input Devices. Interaction Techniques for 3D Manipulation. Design Guidelines. 6. Travel. Introduction. 3D Travel Tasks. Travel Techniques. Design Guidelines. 7. Wayfinding. Introduction. Theoretical Foundations. User-Centered Wayfinding Support. Environment-Centered Wayfinding Support. Evaluating Wayfinding Aids. Design Guidelines. Conclusion. 8. System Control. Introduction. Classification. Graphical Menus. Voice Commands. Gestural Commands. Tools. Multimodal System Control Techniques. Design Guidelines. Case Study: Mixing System Control Methods. 8.10. Conclusion. 9. Symbolic Input. Introduction. Symbolic Input Tasks. Symbolic Input Techniques. Design Guidelines. Beyond Text and Number Entry. IV. DESIGNING AND DEVELOPING 3D USER INTERFACES. 10. Strategies for Designing and Developing 3D User Interfaces. Introduction. Designing for Humans. Inventing 3D User Interfaces. Design Guidelines. 11. Evaluation of 3D User Interfaces. Introduction. Background. Evaluation Metrics for 3D Interfaces. Distinctive Characteristics of 3D Interface Evaluation. Classification of 3D Evaluation Methods. Two Multimethod Approaches. Guidelines for 3D Interface Evaluation. V. THE FUTURE OF 3D USER INTERFACES. 12. Beyond Virtual: 3D User Interfaces for the Real World. Introduction. AR Interfaces as 3D Data Browsers. 3D Augmented Reality Interfaces. Augmented Surfaces and Tangible Interfaces. Tangible AR Interfaces. Agents in AR. Transitional AR-VR Interfaces. Conclusion. 13. The Future of 3D User Interfaces. Questions about 3D UI Technology. Questions about 3D Interaction Techniques. Questions about 3D UI Design and Development. Questions about 3D UI Evaluation. Million-Dollar Questions. Appendix A: Quick Reference Guide to 3D User Interface Mathematics. Scalars. Vectors. Points. Matrices. Quaternions. Bibliography. Index.