Publications
Semi-Automated Guided Teleportation through Immersive Virtual Environments
We present a semi-automated, hands-free path traversal technique based on teleportation that features a slow-paced interaction workflow targeted at fostering knowledge acquisition and maintaining spatial awareness. In an empirical user study with 34 participants, we evaluated two variations of our technique, differing in the presence or absence of intermediate teleportation points between the main points of interest along the route. While visiting additional intermediate points was objectively less efficient, our results indicate significant benefits of this approach regarding the user’s spatial awareness and perception of interface dependability.
Travel Speed, Spatial Awareness, And Implications for Egocentric Target-Selection-Based Teleportation - A Replication Design
Prior research by Bowman et al. highlighted the impact of travel speed on spatial awareness demonstrating that instantaneous travel can lead to user disorientation. However, additional cues, such as visual target selection, can aid in reorientation. This study replicates and extends Bowman’s experiment, investigating the influence of travel speed and visual target cues on spatial orientation.
Webcam-based Hand- and Object-Tracking for a Desktop Workshops in Virtual Reality
As virtual reality overlays the user’s view, challenges arise when interaction with their physical surroundings is still needed. In a seated workspace environment, interaction with the physical surroundings can be essential to enable productive working. Interaction with, e.g., physical mouse and keyboard can be difficult when no visual reference is given to where they are placed. This demo shows a combination of computer vision-based marker detection with machine-learning-based hand detection to bring users' hands and arbitrary objects into VR.
Virtual Reality as a Tool for Monitoring Additive Manufacturing Processes via Digital Shadows
We present a data acquisition and visualization pipeline that allows experts to monitor additive manufacturing processes, in particular laser metal deposition with wire (LMD-w) processes, in immersive virtual reality. In an exploratory user study with 22 participants, we demonstrate that our system is generally suitable for the supervision of LMD-w processes while generating low task load and cybersickness.
Come Look at This: Supporting Fluent Transitions between Tightly and Loosely Coupled Collaboration in Social Virtual Reality
Collaborative work in social virtual reality often requires an interplay of loosely coupled collaboration from different virtual locations and tightly coupled face-to-face collaboration. Without appropriate system mediation, however, transitioning between these phases requires high navigation and coordination efforts. We present a theoretical framework as well as an interaction system that allows collaborators in virtual reality to seamlessly switch between different collaboration models known from related work.
Try This for Size: Multi-Scale Teleportation in Immersive Virtual Reality
We present three novel teleportation-based techniques that enable users to adjust their own scale while traveling through virtual environments. Our approaches build on the extension of known teleportation workflows and suggest specifying scale adjustments either simultaneously with, as a connected second step after, or separately from the user’s new horizontal position. The results of a user study with 30 participants indicate that the simultaneous and connected specification paradigms are both suitable candidates for effective and comfortable multi-scale teleportation with nuanced individual benefits.
IntenSelect+: Enhancing Score-Based Selection in Virtual Reality
We present an enhanced version of the score-based selection technique IntenSelect called IntenSelect+ to overcome multiple shortcomings of the original approach. In an empirical within-subjects user study with 42 participants, we compared IntenSelect+ to IntenSelect and conventional raycasting on a variety of complex object configurations motivated by prior work. In addition to replicating the previously shown benefits of IntenSelect over raycasting, our results also demonstrate significant advantages of IntenSelect+ over IntenSelect regarding selection performance, task load, and user experience.
On the Computation of User Placements for Virtual Formation Adjustments during Group Navigation
Rearranging users into a new formation is a key component of successful group navigation techniques. However, the question of how users should be distributed within the new formation to create an intuitive transition that minimizes disruptions of ongoing social activities is currently not explored. In this paper, we begin to close this gap by introducing four user placement strategies based on mathematical considerations, discussing their benefits and drawbacks, and sketching further novel ideas to approach this topic from different angles in future work.
TENETvr: Comprehensible Temporal Teleportation in Time-Varying Virtual Environments
We present a novel technique called TENETvr that allows for efficient teleportation-based travel in time-varying virtual environments to key moments in which a particular object of interest changed. Unlike previous systems, we suggest that changes affecting other objects should be mediated in advance to improve predictability. In a formal user study with 20 participants, we confirmed that this addition leads to significantly more efficient change detection, lower task loads, and higher usability ratings, therefore reducing temporal disorientation.
Who Did What When? Discovering Complex Historical Interrelations in Immersive Virtual Reality
Traditional tools for exploring historical data mostly rely on conventional 2D visualizations, which often cannot reveal all relevant interrelationships between historical fragments. We present a novel exploration tool for historical data in VR, which represents fragments as spheres in a 3D environment and arranges them based on their temporal, geo, categorical and semantic similarity. Results from a user study revealed that most participants considered our approach well-suited to discover complex interrelationships. These results were underlined by high usability scores while not imposing unexpectedly high task loads.
Stay Vigilant: The Threat of a Replication Crisis in VR Locomotion Research
In this paper, we summarize key replication challenges as well as their specific consequences for VR locomotion research. We then present the results of a literature review on artificial locomotion techniques, in which we analyzed 61 papers published in the last five years with respect to their report of essential details required for reproduction. Our results indicate several issues in terms of the description of the experimental setup, the scientific rigor of the research process, and the generalizability of results, which altogether points towards a potential replication crisis in VR locomotion research. As a countermeasure, we provide guidelines to assist researchers with reporting future artificial locomotion experiments in a reproducible form.
Gaining the High Ground: Teleportation to Mid-Air Targets in Immersive Virtual Environments
We present three teleportation techniques that enable the user to travel not only to ground-based but also to mid-air targets. The techniques differ in the extent to which elevation changes are integrated into the conventional target selection process, either simultaneously, as a connected second step, or separately from horizontal movements. Based on the results of a user study with 30 participants, we define initial design guidelines for mid-air navigation techniques in virtual reality.
Enhanced Auditoriums for Attending Talks in Social Virtual Reality
Replicating traditional auditorium layouts for attending talks in social virtual reality often results in poor visibility of the presentation and a reduced feeling of being there together with others. Motivated by the use case of academic conferences, we present two orthogonal enhancements for virtual auditoriums to overcome these limitations and report on their positive effects as observed in an initial user study with groups.
Towards Discovering Meaningful Historical Relationships in Virtual Reality
We present our work in progress on a novel interactive exploration tool for historical data in virtual reality, which arranges fragments around the user based on their temporal, spatial and categorical proximity to a reference fragment. We then report on an initial expert review of our approach, giving us valuable insights into the use cases and requirements for our further developments.
Holding Hands for Short-Term Group Navigation in Social Virtual Reality
Prior research has shown that social interactions in VR benefit from techniques for group navigation that bring multiple users to a common destination together. In this work, we propose the metaphor of holding onto another user’s virtual hand for the ad-hoc formation of a navigational group and report on the positive results of an initial usability study in an exploratory two-user scenario.
Virtual Rotations for Maneuvering in Immersive Virtual Environments
We present Anchored Jumping, a teleportation technique for maneuvering that allows the explicit specification of a new viewing direction by selecting a point of interest as part of the target specification process. We show that Anchored Jumping allows precise and comfortable maneuvering and is compatible with techniques that mainly support virtual exploration and search.
Group Navigation in Multi-User Virtual Reality
This thesis suggests the use of group navigation techniques in multi-user virtual reality to support groups in their efforts of getting to a common destination together. It presents research results manifested in four peer-reviewed scientific publications, which confirm that group navigation techniques are a valuable addition to the portfolio of interaction techniques in multi-user virtual reality systems. The presented conceptual framework, the derived quality requirements, and the development of novel group navigation techniques provide effective guidance for application developers and inform future research in this area.
Group Navigation for Guided Tours in Distributed Virtual Environments
Group navigation techniques should be comprehensible for both the guide and the attendees, assist the group in avoiding collisions with obstacles, and allow the creation of meaningful spatial arrangements with respect to objects of interest. To meet these requirements, we developed a group navigation technique based on short-distance teleportation and evaluated it in an initial user study.
An Overview of Group Navigation in Multi-User Virtual Reality
We review the different facets, the resulting challenges, and previous implementations of group navigation techniques in the literature and derive four broad and non-exclusive topic areas for future research on the subject. Our overarching goal is to underline the importance of optimizing navigation processes for groups and to increase the awareness of group navigation techniques as a relevant solution approach in this regard.
Multi-Window 3D Interaction for Collaborative Virtual Reality
We present a novel collaborative virtual reality system that offers multiple immersive 3D views at large 3D scenes. The physical setup consists of two synchronized multi-user 3D displays - a tabletop and a large vertical projection screen. Our developments enable seamless 3D interaction across these independent 3D views.
Getting There Together: Group Navigation in Distributed Virtual Environments
We analyzed the design space of group navigation tasks in distributed virtual environments and present a framework consisting of techniques to form groups, distribute responsibilities, navigate together, and eventually split up again. To improve joint navigation, our work focused on an extension of the Multi-Ray Jumping technique that allows adjusting the spatial formation of two distributed users as part of the target specification process.
On the Usage of the Simulator Sickness Questionnaire for Virtual Reality Research
We illustrate the inherent challenges of applying the SSQ in virtual reality research and highlight large differences that can be found in related work. Based on our observations, we conclude by providing suggestions on how to improve the expressiveness of SSQ results in future studies and encourage researchers to consider simpler measurement methods if their research questions allow.
Tracking Multiple Collocated HTC Vive Setups in a Common Coordinate System
Multiple collocated HTC Vive setups sharing the same base stations and room calibration files still track their devices in different coordinate systems. We present a procedure for mapping the tracking data of multiple users to a common coordinate system and show that it enables spatially consistent interactions of collocated collaborators.
Multi-Ray Jumping: Comprehensible Group Navigation for Collocated Users in Immersive Virtual Reality
In this paper, we focus on the design and evaluation of short-range teleportation techniques (jumping) for a group of collocated users wearing head-mounted displays. We formulate the requirements for comprehensible group jumping and propose a novel Multi-Ray Jumping technique for the joint travel of collocated dyads.
Spatial Updating and Simulator Sickness During Steering and Jumping in Immersive Virtual Environments
In this paper, we present a formal description and classification scheme for teleportation techniques and its application to the classification of jumping, a range-restricted variant of teleportation for exploring virtual environments. In addition, we demonstrate the results of a user study that compared jumping to the more conventional steering regarding spatial updating and simulator sickness.
Navigation in Immersive Virtual Reality - The Effects of Steering and Jumping Techniques on Spatial Updating (Extended Thesis Abstract)
This thesis describes navigation by jumping, a range-restricted variant of teleportation commonly implemented in modern VR applications. It illustrates the design space of jumping techniques and evaluates them with respect to spatial orientation performance and simulator sickness. The results indicate that jumping is a viable alternative to steering.
ShakeCast: Using Handshake Detection for Automated, Setup-Free Exchange of Contact Data
We present ShakeCast, a system for automatic peer-to-peer exchange of contact information between two persons who just shook hands. The accelerometer in a smartwatch is used to detect the physical handshake and implicitly triggers a setup-free information transfer between the users' personal smartphones using Bluetooth LE broadcasts.
Navigation in Immersive Virtual Reality - The Effects of Steering and Jumping Techniques on Spatial Updating
The goal of this thesis is to extend previous research by investigating spatial awareness in immersive Virtual Reality when using active, user-initiated jumping techniques in comparison to the one obtained by traditional steering. For this purpose, the thesis explores spatial awareness on different fidelity levels, thereby focusing on the measure of spatial updating for its quantification.
The Massive Mobile Multiuser Framework: Enabling Ad-Hoc Realtime Interaction on Public Displays with Mobile Devices
In this paper, we present the Massive Mobile Multiuser (M³) framework, a software platform designed to enable setup-free, real-time, concurrent interaction with shared public displays through large numbers of personal mobile devices. M³ enables immediate interaction through the mobile browser without requiring prior setup on the user side and real-time interaction suitable for fast multiplayer games.
MMM Ball: Showcasing the Massive Mobile Multiuser Framework
We present a live demonstration of the Massive Mobile Multiuser (M³) framework at the example of a public game which has already been shown to support up to 17 concurrent users. Despite a resource-constrained environment and an unpredictable selection of client devices, M³ consistently delivers performance suitable for real-time interaction.
Konfigurierbare und generische Applikationsinfrastrukturen für 3D-Multi-User-Multi-Display-Umgebungen in der Virtuellen Realität
Ziel dieser Bachelorarbeit ist es, eine konfigurierbare und generische Applikationsinfrastruktur für Multi-Display-Umgebungen im Kontext der Virtuellen Realität zu schaffen. Neben Kriterien der technischen Realisierbarkeit werden dafür zwei Implementierungsstrategien aufgezeigt. Beide Implementierungsstrategien werden hinsichtlich ihrer Machbarkeit bezüglich eines definierten Anforderungskatalogs diskutiert.
