From video games to mobile augmented reality, 3D interaction is everywhere. But simply choosing to use 3D input or 3D displays isn''t enough: 3D user interfaces (3D UIs) must be carefully designed for optimal user experience. 3D User Interfaces: Theory and Practice, Second Edition is today''s most comprehensive primary reference to building outstanding 3D UIs.Four pioneers in 3D user interface research and practice have extensively expanded and updated this book, making it today''s definitive source for all things related to state-of-the-art 3D interaction.   This edition goes far beyond VR, covering the full spectrum of emerging applications for 3D UIs, and presenting an extraordinary array of pioneering techniques and technologies.The authors combine theoretical foundations, analysis of devices and techniques, empirically validated design guidelines, and much more. Throughout each chapter, they illustrate key concepts with running case studies on gaming, mobile AR, and robot teleoper