ABSTRACT - With emerging trends of notifying persons through ubiquitous technologies, such as ambient light, vibrotactile, or auditory cues, none of these technologies are truly ubiquitous and have proven to be easily missed or ignored. In this work, we propose Slappyfications, a novel way of sending unmissable embodied and ubiquitous notifications over a distance. Our proof-of-concept prototype enables the users to send three types of Slappyfications: poke, slap, and the STEAM-HAMMER. Through a Wizard-of-Oz study, we show the applicability of our system in real-world scenarios. The results reveal a promising trend, as none of the participants missed a single Slappyfication.
ABSTRACT - From voice commands and air taps to touch gestures on frames: Various techniques for interacting with head-mounted displays (HMDs) have been proposed. While these techniques have both benefits and drawbacks dependent on the current situation of the user, research on interacting with HMDs has not concluded yet. In this paper, we add to the body of research on interacting with HMDs by exploring foot-tapping as an input modality. Through two controlled experiments with a total of 36 participants, we first explore direct interaction with interfaces that are displayed on the floor and require the user to look down to interact. Secondly, we investigate indirect interaction with interfaces that, although operated by the user's feet, are always visible as they are floating in front of the user. Based on the results of the two experiments, we provide design recommendations for direct and indirect foot-based user interfaces.
ABSTRACT - Room-scale Virtual Reality (VR) systems have arrived in users’ homes where tracked environments are set up in limited physical spaces. As most Virtual Environments (VEs) are larger than the tracked physical space, locomotion techniques are used to navigate in VEs. Currently, in recent VR games, point & teleport is the most popular locomotion technique. However, it only allows users to select the position of the teleportation and not the orientation that the user is facing after the teleport. This results in users having to manually correct their orientation after teleporting and possibly getting entangled by the cable of the headset. In this paper, we introduce and evaluate three diferent point & teleport techniques that enable users to specify the target orientation while teleporting. The results show that, although the three teleportation techniques with orientation indication increase the average teleportation time, they lead to a decreased need for correcting the orientation after teleportation.
ABSTRACT - With head-mounted displays (HMDs), users can access and interact with a broad range of applications and data. Although some of this information is privacy-sensitive or even confidential, no intuitive, unobtrusive and secure authentication technique is available yet for HMDs. We present LookUnlock, an authentication technique for HMDs that uses passwords that are composed of spatial and virtual targets. Through a proof-of-concept implementation and security evaluation, we demonstrate that this technique can be efficiently used by people and is resistant to shoulder-surfing attacks.
ABSTRACT - Internet voting has promising benefits, such as cost reduction, but it also introduces drawbacks: the computer, that is used for voting, learns the voter's choice. Code voting aims to protect the voter's choice by the introduction of voting codes that are listed on paper. To cast a vote, the voters need to provide the voting code belonging to their choice. The additional step influences the usability. We investigate three modalities for entering voting codes: manual, QR-codes and tangibles. The results show that QR-codes offer the best usability while tangibles are perceived as the most novel and fun.
ABSTRACT - Locomotion in Virtual Reality (VR) is an important topic as there is a mismatch between the size of a Virtual Environment and the physically available tracking space. Although many locomotion techniques have been proposed, research on VR locomotion has not concluded yet. In this demonstration,we contribute to the area of VR locomotion by introducing VRChairRacer. VRChairRacer introduces a novel mapping the velocity of a racing cart on the backrest of an office chair. Further, it maps a users’ rotation onto the steering of a virtual racing cart. VRChairRacer demonstrates this locomotion technique to the community through an immersive multiplayer racing demo.
ABSTRACT - Human body postures are an important input modality for motion guidance and other application domains in HCI, e.g. games, character animations, and interaction with public displays. However, for training and guidance of body postures prior research had to define their own whole body gesture sets. Hence, the interaction designs and evaluation results are difficult to compare, due to a lack of a standardized posture set. In this work, we contribute APS (APS Posture Set), a novel posture set including 40 body postures. It is based on prior research, sports, and body language. For each identified posture, we collected 3D posture data using a Microsoft Kinect. We make the skeleton data, 3D mesh objects and SMPL data available for future research. Taken together, APS can be used to facilitate design of interfaces that use body gestures and as a reference set for future user studies and system evaluations.
ABSTRACT - With the proliferation of room-scale Virtual Reality (VR), more and more users install a VR system in their homes. When users are in VR, they are usually completely immersed in their application. However, sometimes passersby invade these tracking spaces and walk up to users that are currently immersed in VR to try and interact with them. As this either scares the user in VR or breaks the user's immersion, research has yet to find a way to seamlessly represent physical passersby in virtual worlds. In this paper, we propose and evaluate three different ways to represent physical passersby in a Virtual Environment using Augmented Virtuality. The representations encompass showing a 3D-Scan, showing an Avatar, and showing a 2D-Image of the passerby. Our results show that while a 2D-Image and an Avatar are the fastest representations to spot passersby, the Avatar and the 3D-Scan representations were the most accurate.
ABSTRACT - Virtual Reality Environments (VRE) create an immersive user experience through visual, aural, and haptic sensations. However, the latter is often limited to vibrotactile sensations that are not able to actively provide kinesthetic motion actuation. Further, such sensations do not cover natural representations of physical forces, for example, when lifting a weight. We present PneumAct, a jacket to enable pneumatically actuated kinesthetic movements of arm joints in VRE. It integrates two types of actuators inflated through compressed air: a Contraction Actuator and an Extension Actuator. We evaluate our PneumAct jacket through two user studies with a total of 32 participants: First, we perform a technical evaluation measuring the contraction and extension angles of different inflation patterns and inflation durations. Second, we evaluate PneumAct in three VRE scenarios comparing our system to traditional controller-based vibrotactile and a baseline without haptic feedback.
ABSTRACT - With the recent advance in computing technology, more and more environments are becoming interactive. For interacting with these environments, traditionally 2D input and output elements are being used. However, recently interaction spaces also expanded to 3D space, which enabled new possibilities but also led to challenges in assisting users with interacting in such a 3D space. Usually, this challenge of communicating 3D positions is solved visually. This paper explores a different approach: spatial guidance through vibrotactile instructions. Therefore, we introduce TactileGlove, a smart glove equipped with vibrotactile actuators for providing spatial guidance in 3D space. We contribute a user study with 15 participants to explore how a different number of actuators and metaphors affect the user performance. As a result, we found that using a Pull metaphor for vibrotactile navigation instructions is preferred by our participants. Further, we found that using a higher number of actuators reduces the target acquisition time than when using a low number.
ABSTRACT - The digitalized world comes with increasing Internet capabilities, allowing to connect persons over distance easier than ever before. Video conferencing and similar online applications create great benefits bringing people who physically cannot spend as much time as they want virtually together. However, such remote experiences can also tend to lose the feeling of traditional experiences. People lack direct visual presence and no haptic feedback is available. In this paper, we tackle this problem by introducing our system called CheckMate. We combine Augmented Reality and capacitive 3D printed objects that can be sensed on an interactive surface to enable remote interaction while providing the same tangible experience as in co-located scenarios. As a proof-of-concept, we implemented a sample application based on the traditional chess game.
ABSTRACT - We are experiencing a trend of integrating computing functionality into more and more common and popular devices. While these so-called smart devices offer many possibilities for automation and personalization of everyday routines, interacting with them and customizing them requires either programming efforts or a smartphone app to control the devices. In this work, we propose and classify Personalized User-Carried Single Button Interfaces as shortcuts for interacting with smart devices. We implement a proof-of-concept of such an interface for a coffee machine. Through an in-the-wild deployment of the coffee machine for approximately three months, we report first initial experiences from 40 participants of using PUCSBIs for interacting with smart devices.
ABSTRACT - Embedding sensors into objects allow them to recognize various interactions.However, sensing usually requires active electronics that are often costly, need time to be assembled, and constantly draw power. Thus, we propose off-line sensing: passive 3D-printed sensors that detect one-time interactions, such as accelerating or flipping, but neither require active electronics nor power at the time of the interaction. They memorize a pre-defined interaction via an embedded structure filled with a conductive medium (e.g., a liquid). Whether a sensor was exposed to the interaction can be read-out via a capacitive touchscreen. Sensors are printed in a single pass on a consumer-level 3D printer. Through a series of experiments, we show the feasibility of off-line sensing.
ABSTRACT - Tangible interaction has shown to be beneficial in a wide variety of scenarios since it provides more direct manipulation and haptic feedback. Further, inherently three-dimensional information is represented more naturally by a 3D object than by a flat picture on a screen. Yet, today's tangibles have often pre-defined form factors and limited input and output facilities. To overcome this issue, the combination of projection and depth cameras is used as a fast and flexible way of non-intrusively adding input and output to tangibles. However, tangibles are often quite small and hence the space for output and interaction on their surface is limited. Therefore, we propose FlowPut: an environment-aware framework that utilizes the space available on and around a tangible object for projected visual output. By means of an optimization-based layout approach, FlowPut considers the environment of the objects to avoid interference between projection and real-world objects. Moreover, we contribute an occlusion resilient object recognition and tracking for tangible objects based on their 3D model and a point-cloud based multi-touch detection, that allows sensing touches also on the side of a tangible. Flowput is validated through a series of technical experiments, a user study, and two example applications.
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