More and more universities are looking for solutions to integrate virtual reality (VR) into teaching and research. But most of the VR systems available for educational purposes are difficult to use without technical expertise, yet. This ability to operate easily, however, would make VR particularly valuable in the classroom. Therefore, this paper describes an exploratory study of university teachers' perceptions on authoring tools in an immersive virtual reality environments. The goal was to get an overview which of these tools, e.g. creation of 3D objects and annotations, teachers consider usable and useful. Overall, all 14 participants in the study were enthusiastic about the possibilities of content creation in VR. For the most part, they found the authoring tools easy to use and see their usefulness for teaching with respect to this first impression.

Augmented reality applications allow users to enrich their real surroundings with additional digital content. However, due to the limited field of view of augmented reality devices, it can sometimes be difficult to become aware of newly emerging information inside or outside the field of view. Typical visual conflicts like clutter and occlusion of augmentations occur and can be further aggravated especially in the context of dense information spaces. In this article, we evaluate how multisensory cue combinations can improve the awareness for moving out-of-view objects in narrow field of view augmented reality displays. We distinguish between proximity and transition cues in either visual, auditory or tactile manner. Proximity cues are intended to enhance spatial awareness of approaching out-of-view objects while transition cues inform the user that the object just entered the field of view. In study 1, user preference was determined for 6 different cue combinations via forced-choice decisions. In study 2, the 3 most preferred modes were then evaluated with respect to performance and awareness measures in a divided attention reaction task. Both studies were conducted under varying noise levels. We show that on average the Visual-Tactile combination leads to 63% and Audio-Tactile to 65% faster reactions to incoming out-of-view augmentations than their Visual-Audio counterpart, indicating a high usefulness of tactile transition cues. We further show a detrimental effect of visual and audio noise on performance when feedback included visual proximity cues. Based on these results, we make recommendations to determine which cue combination is appropriate for which application.

This paper introduces FaceHaptics, a novel haptic display based on a robot arm attached to a head-mounted virtual reality display. It provides localized, multi-directional and movable haptic cues in the form of wind, warmth, moving and single-point touch events and water spray to dedicated parts of the face not covered by the head-mounted display.The easily extensible system, however, can principally mount any type of compact haptic actuator or object. User study 1 showed that users appreciate the directional resolution of cues, and can judge wind direction well, especially when they move their head and wind direction is adjusted dynamically to compensate for head rotations. Study 2 showed that adding FaceHaptics cues to a VR walkthrough can significantly improve user experience, presence, and emotional responses.

Telepresence robots allow people to participate in remote spaces, yet they can be difficult to manoeuvre with people and obstacles around. We designed a haptic-feedback system called "FeetBack," which users place their feet in when driving a telepresence robot. When the robot approaches people or obstacles, haptic proximity and collision feedback are provided on the respective sides of the feet, helping inform users about events that are hard to notice through the robot's camera views. We conducted two studies: one to explore the usage of FeetBack in virtual environments, another focused on real environments. We found that FeetBack can increase spatial presence in simple virtual environments. Users valued the feedback to adjust their behaviour in both types of environments, though it was sometimes too frequent or unneeded for certain situations after a period of time. These results point to the value of foot-based haptic feedback for telepresence robot systems, while also the need to design context-sensitive haptic feedback.

Current augmented reality displays still have a very limited field of view compared to the human vision. In order to localize out-of-view objects, researchers have predominantly explored visual guidance approaches to visualize information in the limited (in-view) screen space. Unfortunately, visual conflicts like cluttering or occlusion of information often arise, which can lead to search performance issues and a decreased awareness about the physical environment. In this paper, we compare an innovative non-visual guidance approach based on audio-tactile cues with the state-of-the-art visual guidance technique EyeSee360 for localizing out-of-view objects in augmented reality displays with limited field of view. In our user study, we evaluate both guidance methods in terms of search performance and situation awareness. We show that although audio-tactile guidance is generally slower than the well-performing EyeSee360 in terms of search times, it is on a par regarding the hit rate. Even more so, the audio-tactile method provides a significant improvement in situation awareness compared to the visual approach.

We present a novel, multilayer interaction approach that enables state transitions between spatially above-screen and 2D on-screen feedback layers. This approach supports the exploration of haptic features that are hard to simulate using rigid 2D screens. We accomplish this by adding a haptic layer above the screen that can be actuated and interacted with (pressed on) while the user interacts with on-screen content using pen input. The haptic layer provides variable firmness and contour feedback, while its membrane functionality affords additional tactile cues like texture feedback. Through two user studies, we look at how users can use the layer in haptic exploration tasks, showing that users can discriminate well between different firmness levels, and can perceive object contour characteristics. Demonstrated also through an art application, the results show the potential of multilayer feedback to extend on-screen feedback with additional widget, tool and surface properties, and for user guidance.

Head-worn devices with a narrow field of view are common commodity for Augmented Reality. However, their limited screen space makes view management difficult. Especially in dense information spaces this potentially leads to visual conflicts such as overlapping labels (occlusion) and visual clutter. In this paper, we look into the potential of using audio and vibrotactile feedback to guide search and information localization. Our results indicate users can be guided with high accuracy using audio-tactile feedback with maximum median deviations of only 2° on longitude, 3.6° on latitude and 0.07 meter in depth. Regarding the encoding of latitude we found a superior performance when using audio, resulting in an improvement of 61% and fastest search times. When interpreting localization cues the maximum median deviation was 9.9° on longitude and 18% of a selected distance to be encoded which could be reduced to 14% when using audio.

Many optical-see-through displays have a relatively narrow field of view. However, a limited field of view can constrain how information can be presented and searched through. To understand these constraints, we present a series of experiments that address the interrelationships between field of view, information density, and search performance. We do so by simulating various fields of view using two approaches: limiting the field of view presented on a Microsoft HoloLens optical-see-through head-worn display and dynamically changing the portion of a large tiled-display wall on which information is presented, for head-tracked users in both cases. Our results indicate a significant effect of information density and field of view on search performance, with potential search performance benefits of using a larger FOV between ca. 7-28%. Furthermore, while grids guided visual search, they did not significantly affect performance.

In this research demo, we show different examples for the integration of multisensory cues to enhance user engagement and trigger emotional responses in immersive environments. Our primary focus is to use this modular-designed system for the supportive treatment of different anxiety disorders.

In presence of conflicting or ambiguous visual cues in complex scenes, performing 3D selection and manipulation tasks can be challenging. To improve motor planning and coordination, we explore audio-tactile cues to inform the user about the presence of objects in hand proximity, e.g., to avoid unwanted object penetrations. We do so through a novel glove-based tactile interface, enhanced by audio cues. Through two user studies, we illustrate that proximity guidance cues improve spatial awareness, hand motions, and collision avoidance behaviors, and show how proximity cues in combination with collision and friction cues can significantly improve performance.

We present a novel forearm-and-glove tactile interface that can enhance 3D interaction by guiding hand motor planning and coordination. In particular, we aim to improve hand motion and pose actions related to selection and manipulation tasks. Through our user studies, we illustrate how tactile patterns can guide the user, by triggering hand pose and motion changes, for example to grasp (select) and manipulate (move) an object. We discuss the potential and limitations of the interface, and outline future work.

Enhancing touch screen interfaces through non-visual cues has been shown to improve performance. In this paper we report on a novel system that explores the usage of a forcesensitive motion-platform enhanced tablet interface to improve multi-modal interaction based on visuo-haptic instead of tactile feedback. Extending mobile touch screen with force-sensitive haptic feedback has potential to enhance performance interacting with GUIs and to improve perception of understanding relations. A user study was performed to determine the perceived recognition of different 3D shapes and the perception of different heights. Furthermore, two application scenarios are proposed to explore our proposed visuo-haptic system. The studies show the positive stance towards the feedback, as well as the found limitations related to perception of feedback.

In this paper, we report on novel zooming interface methods that deploy a small handheld projector. Using mobile projections to visualize object/environment-related information on real objects introduces new aspects for zooming interfaces. Different approaches are investigated that focus on maintaining a level of context while exploring detailed information. Doing so, we propose methods that provide alternative contextual cues within a single projector and deploy the potential of zoom lenses to support a multilevel zooming approach. Furthermore, we look into the correlation between pixel density, distance to the target, and projection size. Alongside these techniques, we report on multiple user studies, in which we quantified the projection limitations and validated various interactive visualization approaches. Thereby, we focused on solving issues related to pixel density, brightness, and contrast that affect the design of more effective legible zooming interfaces for handheld projectors.

This paper introduces a novel zooming interface deploying a pico projector that, instead of a second visual display, leverages audioscapes for contextual information. The technique enhances current flashlight metaphor approaches, supporting flexible usage within the domain of spatial augmented reality to focus on object or environment-related details. Within a user study we focused on quantifying the projection limitations related to depiction of details through the pico projector and validated the interaction approach. The quantified results of the study correlate pixel density, detail and proximity, which can greatly aid to design more effective, legible zooming interfaces for pico projectors - the study can form an example testbed that can be applied well for testing aberrations with other projectors. Furthermore, users rated the zooming technique using audioscapes well, showing the validity of the approach. The studies form the foundation for extending our work by detailing out the audio-visual approach and looking more closely in the role of real-world features on interpreting projected content.

Position awareness in unknown and large indoor spaces represents a great advantage for people, everyday pedestrians have to search for specific places, products and services. In this work a positioning solution able to localize the user based on data measured with a mobile device is described and evaluated. The position estimate uses data from smartphone built-in sensors, WiFi (Wireless Fidelity) adapter and map information of the indoor environment (e.g. walls and obstacles). A probability map derived from statistical information of the users tracked location over a period of time in the test scenario is generated and embedded in a map graph, in order to correct and combine the position estimates under a Bayesian representation. PDR (Pedestrian Dead Reckoning), beacon-based Weighted Centroid position estimates, map information obtained from building OpenStreetMap XML representation and probability map users path density are combined using a Particle Filter and implemented in a smartphone application. Based on evaluations, this work verifies that the use of smartphone hardware components, map data and its semantic information represented in the form of a OpenStreetMap structure provide 2.48 meters average error after 1,700 travelled meters and a scalable indoor positioning solution. The Particle Filter algorithm used to combine various sources of information, its radio WiFi-based observation, probability particle weighting process and the mapping approach allowing the inclusion of new indoor environments knowledge show a promising approach for an extensible indoor navigation system.

A person has to deal with large and unknown scenarios, for example a client searching for a expositor in a trade fair or a passenger looking for a gate in an airport. Due to the fact that position awareness represents a great advantage for people, a navigation system implemented for a commercial smartphone can help the user to save time and money. In this work a navigation example application able to localize and provide directions to a desired destination in an indoor environment is presented and evaluated. The position of the user is calculated with information from the smartphone builtin sensors, WiFi adapter and floor-plan layout of the indoor environment. A commercial smartphone is used as the platform to implement the example application, due to it's hardware features, computational power and the graphic user interface available for the users. Evaluations verified that room accuracy is achieved for robust localization by using the proposed technologies and algorithms. The used optimal sensor fusion filter for different sources of information and the easy to deploy infrastructure in a new environment show promise for mobile indoor navigation systems.