Facebook's purchase of Oculus VR in 2014 ushered in a new era of consumer virtual reality head-mounted displays (HMDs). Converging technological advancements in small, high-resolution displays and motion-detection devices propelled VR beyond the purview of high-tech research laboratories and into the mainstream. However, technological hurdles still remain. As more consumer grade products develop, user comfort and experience will be of the utmost importance. One of the biggest issues for HMDs that lack external tracking is drift in the user position and rotation sensors. Drift can cause motion sickness and make stationary items in the virtual environment to appear to shift in position. For developers who seek to design VR experiences that are rooted in real environments, drift can create large errors in positional tracking if left uncorrected over time. Although much of the current VR hardware makes use of external tracking devices to mitigate positional and rotational drift, the creation of head-mounted displays that can operate without the use of extremal tracking devices would make VR hardware more portable and flexible, and may therefore be a goal for future development.

We discuss a two-handed user interface designed to support three-dimesional neurosurgical visualization. By itself, this system is a “point design,” an example of an advanced user interface technique. In this work, we argue that in order to understand why interaction techniques do or do not work, and to suggest possibilities for new techniques, it is important to move beyond point design and to introduce careful scientific measurement of human behavioral principles. In particular, we argue that the common-sense viewpoint that “two hands save time by working in parallel” may not always be an effective way to think about two-handed interface design because the hands do not necessarily work in parallel (there is a structure to two-handed manipulation) and because two hands do more than just save time over one hand (two hands provide the user with more information and can structure how the user thinks about a task). To support these claims, we present an interface design developed in collaboration with neurosurgeons which has undergone extensive informal usability testing, as well as a pair of formal experimental studies which investigate behavioral aspects of two-handed virtual object manipulation. Our hope is that this discussion will help others to apply the lessons in our neurosurgery application to future two-handed user interface designs.

We present an experiment on cooperative bimanual action.Right-handed subjects manipulated a pair of physical objects, a tool and a target object, so that the tool would touch a target on the object @g. 1).For this task, there is a marked specialization of the hands.Performance is best when the left hand orients the target object and the right hand manipulates the tool, but is significantly reduced when these roles are reversed.This suggests that the right hand operates relative to the frame-of-reference of the left hand.Furthermore, when physical constraints guide the tool placement, this fundamentally changes the type of motor control required.The task is tremendously simplified for both hands, and reversing roles of the hands is no longer an important factor.Thus, specialization of the roles of the hands is significant only for skilled manipulation.

We investigate the synergy of the two hands for virtual object manipuhttion.We report results from an experiment which suggest that the two hands together provide sufficient perceptual cues to form a frame of reference which is independent of visual feedback.The same is not true for one hand moving in empty space.Our inteqmtadon is that users may not have to constantly maintain visual attention when both hands can be involved in a manipulation.Our results suggest that using two hands can provide more than just a time savings over one-handed manipulation.llvo hands together provide the user with information which one hand alone cannot.Our results also suggest that using two hands can potentially impact performance at the cognitive level by changing how users think about a task.Since the user can potentially integrate subtasks controlled by each hand without an explicit cost to switch between subtasks, this encourages exploration of the task solution space.Fhmlly, to illustrate why one might expect this to be true, we present a task analysis which helps to reason about the differences between one and two-handed interfaces.

Virtual Reality (VR) has generated much excitement but little formal proof that it is useful. Because VR interfaces are difficult and expensive to build, the computer graphics community needs to be able to predict which applications will benefit from VR. In this paper, we show that users with a VR interface complete a search task faster than users with a stationary monitor and a hand-based input device. We placed users in the center of the virtual room shown in Figure 1 and told them to look for camouflaged targets. VR users did not do significantly better than desktop users. However, when asked to search the room and conclude if a target existed, VR users were substantially better at determining when they had searched the entire room. Desktop users took 41% more time, re-examining areas they had already searched. We also found a positive transfer of training from VR to stationary displays and a negative transfer of training from stationary displays to VR.

We report results from a formal user study of interactive 3D rotation using the mouse-driven Virtual Sphere and Arcball techniques, as well as multidimensional input techniques based on magnetic orientation sensors. Multidimensional input is often assumed to allow users to work quickly, but at the cost of precision, due to the instability of the hand moving in the open air. We show that, at least for the orientation matching task used in this experiment, users can take advantage of the integrated degrees of freedom provided by multidimensional input without necessarily sacrificing precision: using multidimensional input, users completed the experimental task up to 36% faster without any statistically detectable loss of accuracy. We also report detailed observations of common usability problems when first encountering the techniques. Our observations suggest some design issues for 3D input devices. For example, the physical form-factors of the 3D input device significantly influenced us...