Coordinated Eye and Head Movements for Gaze Interaction in 3D Environments

Gaze is attractive for interaction, as we naturally look at objects we are interested in. As a result, gaze has received significant attention within human-computer interaction as an input modality. However, gaze has been limited to only eye movements in situations where head movements are not expected to be used or as head movements in an approximation of gaze when an eye tracker is unavailable. From these observations arise an opportunity and a challenge: we propose to consider gaze as multi-modal in line with psychology and neuroscience research to more accurately represent user movements. The natural coordination of eye and head movements could then enable the development of novel interaction techniques to further the possibilities of gaze as an input modality. However, knowledge of the eye and head coordination in 3D environments and its usage for interaction design is limited. This thesis explores eye and head coordination and their potential for interaction in 3D environments by developing interaction techniques that aim to tackle established gaze-interaction issues. We study fundamental eye, head, and body movements in virtual reality during gaze shifts. From the study results, we design interaction techniques and applications that avoid the Midas touch issue, allow expressive gaze- based interaction, and handle eye tracking accuracy issues. We ground the evaluation of our interaction techniques through empirical studies. From the techniques and study results, we define three design principles for coordinated eye and head interaction from these works that distinguish between eye- only and head-supported gaze shifts, eye-head alignment as input, and distinguishing head movements for gestures and head movements that naturally occur to support gaze. We showcase new directions for gaze-based interaction and present a new way to think about gaze by taking a more comprehensive approach to gaze interaction and showing that there is more to gaze than just the eyes

Прогностически значимые факторы риска преждевременной общей смертности у лиц с артериальной гипертензией

ГИПЕРТЕНЗИЯСМЕРТНОСТЬФАКТОРЫ РИСК

Eye, Head and Torso Coordination During Gaze Shifts in Virtual Reality

Humans perform gaze shifts naturally through a combination of eye, head and body movements. Although gaze has been long studied as input modality for interaction, this has previously ignored the coordination of the eyes, head and body. This article reports a study of gaze shifts in virtual reality (VR) aimed to address the gap and inform design. We identify general eye, head and torso coordination patterns and provide an analysis of the relative movements' contribution and temporal alignment. We quantify effects of target distance, direction and user posture, describe preferred eye-in-head motion ranges, and identify a high variability in head movement tendency. Study insights lead us to propose gaze zones that reflect different levels of contribution from eye, head and body. We discuss design implications for HCI and VR, and in conclusion argue to treat gaze as multimodal input, and eye, head and body movement as synergetic in interaction design

Gaze+Hold: Eyes-only Direct Manipulation with Continuous Gaze Modulated by Closure of One Eye

The eyes are coupled in their gaze function and therefore usually treated as a single input channel, limiting the range of interactions. However, people are able to open and close one eye while still gazing with the other. We introduce Gaze+Hold as an eyes-only technique that builds on this ability to leverage the eyes as separate input channels, with one eye modulating the state of interaction while the other provides continuous input. Gaze+Hold enables direct manipulation beyond pointing which we explore through the design of Gaze+Hold techniques for a range of user interface tasks. In a user study, we evaluated performance, usability and user’s spontaneous choice of eye for modulation of input. The results show that users are effective with Gaze+Hold. The choice of dominant versus non-dominant eye had no effect on performance, perceived usability and workload. This is significant for the utility of Gaze+Hold as it affords flexibility for mapping of either eye in different configurations

Dynamics of Eye Dominance Behavior in Virtual Reality

Prior research has shown that sighting eye dominance is a dynamic behavior and dependent on horizontal viewing angle. Virtual reality (VR) offers high flexibility and control for studying eye movement and human behavior, yet eye dominance has not been given significant attention within this domain. In this work, we replicate Khan and Crawford’s (2001) original study in VR to confirm their findings within this specific context. Additionally, this study extends its scope to study alignment with objects presented at greater depth in the visual field. Our results align with previous results, remaining consistent when targets are presented at greater distances in the virtual scene. Using greater target distances presents opportunities to investigate alignment with objects at varying depths, providing greater flexibility for the design of methods that infer eye dominance from interaction in VR

BimodalGaze:Seamlessly Refined Pointing with Gaze and Filtered Gestural Head Movement

Eye gaze is a fast and ergonomic modality for pointing but limited in precision and accuracy. In this work, we introduce BimodalGaze, a novel technique for seamless head-based refinement of a gaze cursor. The technique leverages eye-head coordination insights to separate natural from gestural head movement. This allows users to quickly shift their gaze to targets over larger fields of view with naturally combined eye-head movement, and to refine the cursor position with gestural head movement. In contrast to an existing baseline, head refinement is invoked automatically, and only if a target is not already acquired by the initial gaze shift. Study results show that users reliably achieve fine-grained target selection, but we observed a higher rate of initial selection errors affecting overall performance. An in-depth analysis of user performance provides insight into the classification of natural versus gestural head movement, for improvement of BimodalGaze and other potential applications

GE-Simulator:An Open-Source Tool for Simulating Real-Time Errors for HMD-based Eye Trackers

As eye tracking in augmented and virtual reality (AR/VR) becomes established, it will be used by broader demographics, increasing the likelihood of tracking errors. Therefore, it is important when designing eye tracking applications or interaction techniques to test them at different signal quality levels to ensure they function for as many people as possible. We present GE-Simulator, a novel open-source Unity toolkit that allows the simulation of accuracy, precision, and data loss errors during real-time usage by adding gaze vector errors into the gaze vector from the head-mounted AR/VR eye tracker. The tool is customisable without having to change the source code and changes in eye tracking errors during and in-between usage. Our toolkit allows designers to prototype new applications at different levels of eye tracking in the early phases of design and can be used to evaluate techniques with users at varying signal quality levels

Radi-Eye:Hands-Free Radial Interfaces for 3D Interaction using Gaze-Activated Head-Crossing

Eye gaze and head movement are attractive for hands-free 3D interaction in head-mounted displays, but existing interfaces afford only limited control. Radi-Eye is a novel pop-up radial interface designed to maximise expressiveness with input from only the eyes and head. Radi-Eye provides widgets for discrete and continuous input and scales to support larger feature sets. Widgets can be selected with Look & Cross, using gaze for pre-selection followed by head-crossing as trigger and for manipulation. The technique leverages natural eye-head coordination where eye and head move at an offset unless explicitly brought into alignment, enabling interaction without risk of unintended input. We explore Radi-Eye in three augmented and virtual reality applications, and evaluate the effect of radial interface scale and orientation on performance with Look & Cross. The results show that Radi-Eye provides users with fast and accurate input while opening up a new design space for hands-free fluid interaction

Snap, Pursuit and Gain : Virtual Reality Viewport Control by Gaze

Head-mounted displays let users explore virtual environments through a viewport that is coupled with head movement. In this work, we investigate gaze as an alternative modality for viewport control, enabling exploration of virtual worlds with less head movement. We designed three techniques that leverage gaze based on different eye movements: Dwell Snap for viewport rotation in discrete steps, Gaze Gain for amplified viewport rotation based on gaze angle, and Gaze Pursuit for central viewport alignment of gaze targets. All three techniques enable 360-degree viewport control through naturally coordinated eye and head movement. We evaluated the techniques in comparison with controller snap and head amplification baselines, for both coarse and precise viewport control, and found them to be as fast and accurate. We observed a high variance in performance which may be attributable to the different degrees to which humans tend to support gaze shifts with head movement