Li, J. (2017). Effects of Control-Display Mapping on 3D Interaction in Immersive Virtual Environments. Unc Charlotte Electronic Theses And Dissertations.
There is a significant amount of research on the mapping of the interactive control space to the display space in 3D user interfaces. While most work has focused on control-display gain (or ratio), one factor that has received relatively less attention is cursor offset, which is a vector between the input device in physical space and the virtual cursor in display space. Empirical results of the efficiency and usability of a translational offset have been provided by multiple studies, but only for a particular type of interaction, on a specific display system. Anecdotal evidence suggests that results may differ on different types of tasks or in different types of VR systems. Therefore, this research focuses on designing and evaluating virtual cursor offset techniques for 3D interaction in immersive virtual environments in a more comprehensive manner.Three user studies are carried out to explore the effect of various offset techniques on a 7 degree-of-freedom navigation task in a surround-screen CAVE system, for both one-handed and two-handed interactions. Results show that the Linear Offset technique outperforms other offset techniques for exocentric travel tasks and provides superior performance under a variety of conditions.To compare the same offset techniques in an HMD environment, an evaluation on 3D object selection tasks that follows Fitts’ law model under ISO 9241-9 standard using two different input devices is first presented. The result indicates that direct selection of nearby objects with No Offset remains the most efficient and the Linear Offset technique could enhance selection performance with objects at a distance. Further, two experiments on unimanual and bimanual object manipulation are conducted respectively, using the same input devices. For both studies, No Offset does not reveal advantages over Linear Offset or Go-Go Offset when the object is within reach, while for out of reach condition, Linear Offset outperforms Fixed-Length and Go-Go Offset. In all three studies conducted within Oculus Rift DK2, Razer Hydra proves to be more stable and effective than Leap Motion.
