In this paper we discuss the benefits and the limitations, as well as different implementation options for smooth immersion into a HMD-based IVE. We evaluated our concept in a preliminary user study, in which we have tested users’ awareness, reality judgment and experience in the IVE, when using different transition techniques to enter it. Our results show that a smooth transition to the IVE improves the awareness of the user and may increase the perceived interactivity of the system.

The study presented in this paper extends earlier research involving body continuity by investigating if the presence of real body cues (legs that look like and move like one's own) alters one's sense of immersion in a virtual environment. The main hypothesis is that real body cues increase one's sense of body ownership and physical presence, even when those body parts are not essential to the activity on which one is focused. To test this hypothesis, we developed an experiment that uses a virtual human hand and arm that are directly observable but clearly synthetic, and a lower body seen through a virtual mirror, where the legs are sometimes visually accurate and personalized, and other times accurate in movement but not in appearance. The virtual right hand and arm are the focus of our scenario; the lower body, only visible in the mirror, is largely irrelevant to task, only provides perceptually contextual information. By looking at combinations of arm-hand continuity (2 conditions), freedom or lack of it to move the hand (2 conditions), and realism or lack of it of the virtually reflected lower body (2 conditions), we are able to study the effects of each combination on the perceptions of body ownership and presence, critical features in virtual environments involving a virtual surrogate.

This paper contributes ReflectiveSpineVR, an immersive spine surgery simulation enriched with interaction history capabilities aimed to support effective learning and training. The provided interaction history features are based on a design study we conducted exploring what makes an effective interaction history representation in spatial tasks. Existing surgical simulation systems only provide a crude way to supporting repetitive practice where the simulation needs to be restarted every time. By working closely with medical collaborators and following an iterative process, we present our novel approach to enriching users with nonlinear interaction history capabilities and supporting repetitive practice including how such features were realized in our ReflectiveSpineVR prototype. We conclude the paper with the results of a preliminary evaluation of ReflectiveSpineVR, highlighting the positive feedback regarding our history representation approach and the interface benefits.

The retrieval of additional information from public (e.g., map data) or private (e.g., e-mail) information sources using personal smart devices is a common habit in today's co-located conversations. This behavior of users imposes challenges in two main areas: 1) cognitive focus switching and 2) information sharing. In this paper, we explore a novel approach for conversation support through augmented information bits, allowing users to see and access information right in front of their eyes. To that end, we investigate the requirements for the design of a user interface to support conversations through proactive information retrieval in an exploratory study. Based on the results, we 2) present CloudBits: A set of visualization and interaction techniques to provide mutual awareness and enhance coupling in conversations through augmented zero-query search visualization along with its prototype implementation. Finally, we 3) report the findings of a qualitative evaluation and conclude with guidelines for the design of user interfaces for conversation support.

We compare the effectiveness of 2D maps and 3D terrain models for visibility tasks and demonstrate how interactive dynamic viewsheds can improve performance for both types of terrain representations. In general, the two-dimensional nature of classic topographic maps limits their legibility and can make complex yet typical cartographic tasks like determining the visibility between locations difficult. Both 3D physical models and interactive techniques like dynamic viewsheds have the potential to make it improve viewers’ understanding of topography, but their impact has not been deeply explored. We evaluate the effectiveness of 2D maps, 3D models, and interactive viewsheds for both simple and complex visibility tasks. Our results demonstrate the benefits of the dynamic viewshed technique and highlight opportunities for additional tactile interactions with maps and models. Based on these findings we present guidelines for improving the design and usability of future topographic maps and models.

Linear interface controllers such as sliders and scrollbars are primary tools for navigating through linear content such as videos or text documents. Linear control widgets provide an abstract representation of the entire document in the body of the widget, in that they map each document location to a different position of the slider knob or scroll thumb. In most cases, however, these linear mappings are visually undifferentiated – all locations in the widget look the same – and so it can be difficult to build up spatial knowledge of the document, and difficult to navigate back to locations that the user has already visited. In this paper, we examine a technique that can address this problem: artificial landmarks that are added to a linear control widget in order to improve spatial understanding and revisitation. We carried out a study with two types of content (a video, and a PDF document) to test the effects of adding artificial landmarks. We compared standard widgets (with no landmarks) to two augmented designs: one that placed arbitrary abstract icons in the body of the widget, and one that added thumbnails extracted from the document. We found that for both kinds of content, adding artificial landmarks significantly improved revisitation performance and user preference, with the thumbnail landmarks fastest and most accurate in both cases. Our study demonstrates that augmenting linear control widgets with artificial landmarks can provide substantial benefits for document navigation.

Stylo-Handifact is a novel spatial user interface consisting of a haptic device (i.e., Stylo) attached to the forearm and a visualization of a virtual hand (i.e., Handifact), which in combination provide visuo-haptic feedback for posture training applications. In this paper we evaluate the mutual effects of Handifact and Stylo on visuo-haptic sensations in a psychophysical experiment. The results show that a visual stimulus can modulate the perceived strength of a haptic stimulus by more than 5%. A wrist docking task indicates that Stylo-Handifact results in improved task completion time as compared to a state-of-the-art technique.

As shown in many large-scale and longitudinal studies, spatial ability is strongly associated with STEM (science, technology, engineering, and mathematics) learning and career success. At the same time, a growing volume of research connects cognitive science theories with tangible/embodied interactions (TEI) and virtual reality (VR) to offer novel means to support spatial cognition. But very few VR-TEI systems are specifically designed to support spatial ability, nor are they evaluated with respect to spatial ability. In this paper, we present the background, approach, and evaluation of TASC (Tangibles for Augmenting Spatial Cognition), a VR-TEI system built to support spatial perspective taking ability. We tested 3 conditions (tangible VR, keyboard/mouse, control; n=46). Analysis of the pre/post-test change in performance on a perspective taking test revealed that only the VR-TEI group showed statistically significant improvements. The results highlight the role of tangible VR design for enhancing spatial cognition.

Tangible User Interfaces (TUIs) allow for effective and easy interaction with digital information by encapsulating them into a physical form. Especially in combination with interactive surfaces, TUIs have been studied in a variety of forms and application cases. By taking advantage of the human abilities to grasp and manipulate they ease collaboration and learning. In this paper we study the effects of TUIs on spatial memory. In our study we compare participants’ performance of recalling positions of buildings that they priorly placed on an interactive tabletop either using a TUI or a touch-based GUI. While 83,3% of the participants reported in their self assessment that they performed better in recalling the positions when using the GUI our results show that participants were on an average 24.5% more accurate when using the TUI.

We present HaptoBend, a novel shape-changing input device providing passive haptic feedback (PHF) for a wide spectrum of objects in virtual reality (VR). Past research in VR shows that PHF increases presence and improves user task performance. However, providing PHF for multiple objects usually requires complex, immobile systems, or multiple props. HaptoBend addresses this problem by allowing users to bend the device into 2D plane-like shapes and multi-surface 3D shapes. We believe HaptoBend’s physical approximations of virtual objects can provide realistic haptic feedback through research demonstrating the dominance of human vision over other senses in VR. To test the effectiveness of HaptoBend in matching 2D planar and 3D multi-surface shapes, we conducted an experiment modeled after gesture elicitation studies with 20 participants. High goodness and ease scores show shape-changing passive haptic devices, like HaptoBend, are an effective approach to generalized haptics. Further analysis supports the use of physical approximations for realistic haptic feedback.

We present a study comparing selection performance between three eye/head interaction techniques using the recently released FOVE head-mounted display (HMD). The FOVE offers an integrated eye tracker, which we use as an alternative to potentially fatiguing and uncomfortable head-based selection used with other commercial devices. Our experiment was modelled after the ISO 9241-9 reciprocal selection task, with targets presented at varying depths in a custom virtual environment. We compared eye-based selection, and head-based selection (i.e., gaze direction) in isolation, and a third condition which used both eye-tracking and head-tracking at once. Results indicate that eye-only selection offered the worst performance in terms of error rate, selection times, and throughput. Head-only selection offered significantly better performance.

Virtual reality affords experimentation with human abilities beyond what's possible in the real world, toward novel senses of interaction. In many interactions, the eyes naturally point at objects of interest while the hands skilfully manipulate in 3D space. We explore a particular combination for virtual reality, the Gaze + Pinch interaction technique. It integrates eye gaze to select targets, and indirect freehand gestures to manipulate them. This keeps the gesture use intuitive like direct physical manipulation, but the gesture's effect can be applied to any object the user sees --- whether located near or far. In this paper, we describe novel interaction concepts and an experimental system prototype that bring together interaction technique variants, menu interfaces, and applications into one unified virtual experience. Early application examples were developed and tested, including 3D manipulation, scene navigation, and image zooming, illustrating a range of advanced interaction capabilities on targets at any distance, without using controllers.

Head-mounted displays allow user to augment reality or dive into a virtual one. However, these 3D spaces often come with problems due to objects that may be out of view. Visualizing these out-of-view objects is useful under certain scenarios, such as situation monitoring during ship docking. To address this, we designed a lo-fi prototype of our EyeSee360 system, and based on user feedback, subsequently implemented EyeSee360. We evaluate our technique against well-known 2D off-screen object visualization techniques (Arrow, Halo, Wedge) adapted for head-mounted Augmented Reality, and found that EyeSee360 results in lowest error for direction estimation of out-of-view objects. Based on our findings, we outline the limitations of our approach and discuss the usefulness of our developed lo-fi prototyping tool.

We implemented the input interface named ‘Novest’ which can estimate the finger position and classify the finger state (out-of-range/hovering/touching) on the back of a hand with a small ranging sensor array attached on the side of a smartwatch, each of the small ranging sensors gets distance data and strength of signal data. With a prototype of Novest, we conducted the first evaluation to assess the basic performance. In this paper, we conducted the formal user study with two different conditions: the sitting/standing conditions to evaluate the practical perfor-mance of Novest as an input interface. The results show that the finger position estimation accuracies in the sitting and standing conditions are 4.2 mm and 5.0 mm, respectively. Additionally, the finger state classification accuracies with parameters adjust-ed by grid search in the sitting and standing conditions are 97.2% and 97.9%, respectively.

Existing empty-handed mid-air interaction techniques for system control are typically limited to a confined gesture set or point-and-select on graphical user interfaces. In this paper, we introduce GestureDrawer, a one-handed interaction with a 3D imaginary interface. Our approach allows users to self-define an imaginary interface, acquire visuospatial memory of the position of its controls in empty space and enables them to select or manipulate those controls by moving their hand in all three dimensions. We evaluate our approach with three user studies and demonstrate that users can indeed position imaginary controls in 3D empty space and select them with an accuracy of 93% without receiving any feedback and without fixed land-marks (e.g. second hand). Further, we show that imaginary interaction is generally faster than mid-air interaction with graphical user interfaces, and that users can retrieve the position of their imaginary controls even after a proprioception disturbance. We condense our findings into several design recommendations and present automotive applications.

Most current virtual reality (VR) applications use some form of teleportation to cover large distances, or real walking in room-scale setups for moving in virtual environments. Though real walking is the most natural for medium distances, it gets physically demanding and inefficient after prolonged use, while the sudden viewpoint changes experienced with teleportation often lead to disorientation. To close the gap between travel over long and short distances, we introduce TriggerWalking a biomechanically-inspired locomotion user interface for efficient realistic virtual walking. The idea is to map the human’s embodied ability for walking to a finger-based locomotion technique. Using the triggers of common VR controllers, the user can generate near-realistic virtual bipedal steps. We analyzed head oscillations of VR users while they walked with a head-mounted display, and used the data to simulate realistic walking motions with respect to the trigger pulls. We evaluated how the simulation of walking biomechanics affects task performance and spatial cognition. We also compared the usability of TriggerWalking with joystick, teleportation, and walking in place. The results show that users can efficiently use TriggerWalking, while still benefiting from the inherent advantages of real walking.