ICAT-EGVE2018
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Item Positioning of Subtitles in Cinematic Virtual Reality(The Eurographics Association, 2018) Rothe, Sylvia; Tran, Kim; Hussmann, Heinrich; Bruder, Gerd and Yoshimoto, Shunsuke and Cobb, SueCinematic Virtual Reality has been increasing in popularity in recent years.Watching 360 degree movies with a head mounted display, the viewer can freely choose the direction of view and thus the visible section of the movie. Therefore, a new approach for the placements of subtitles is needed. In a preliminary study we compared several static methods, where the position of the subtitles is not influenced by the movie content. The preferred method was used in the main study to compare it with dynamic, worldreferenced subtitling, where the subtitles are placed in the movie world. The position of the subtitles depends on the scene and is close to the speaking person. Even if the participants did not prefer one of these methods in general, for some cases in our experiments world-referenced subtitles led to a higher score of presence, less sickness and lower workload.Item Equivalent Physical Constant Hypothesis for Skill Transmission in Scale Conversion Telexistence(The Eurographics Association, 2018) Miyamoto, Hiroki; Furukawa, Masahiro; Wada, Kosuke; Kurokawa, Masataka; Matsumoto, Kohei; Maeda, Taro; Bruder, Gerd and Yoshimoto, Shunsuke and Cobb, SueScale conversion telexistence can have an inconsistency in the motions of a human and robot of different scales. We assumed that the inconsistency is caused by the different apparent physical constants for the human and robot. We propose an equivalent physical constant hypothesis for motion skill transmission, which we verified experimentally by transmitting the standing-up movement of a human to a small robot. The robot successfully managed to stand up by compensating for the gravity. This proves the validity of the hypothesis.Item Studying Levels of Presence in a Virtual Environment Simulating Drug Use in Schools: Effect on Different Character Perspectives(The Eurographics Association, 2018) Christofi, Maria; Baka, Evangelia; Stavroulia, Kalliopi Evangelia; Michael-Grigoriou, Despina; Lanitis, Andreas; Thalmann, Nadia Magnenat; Bruder, Gerd and Yoshimoto, Shunsuke and Cobb, SueThis paper studies the aspect of presence in a Virtual Reality (VR) environment that can be used for training purposes in the education sector and more specifically for teacher training and professional development. During the VR experience trainees had the chance to view the world from different perspectives through the eyes of different characters appearing in the scene. The experimental evaluation conducted aims to examine the effect of viewing the experience from different perspectives and viewpoints in relation to the overall user experience and the level of presence achieved. To accomplish these objectives an experiment was performed investigating presence and the correlation between presence and different viewpoints/perspectives. To measure presence a combination of methods were used including two different questionnaires, the use of an eeg device, EMOTIV EPOC+ and the analysis of heart rates. The results indicate that high levels of presence were recorded and that increased levels of presence are associated with viewing the VE from a student rather than a teacher perspective.Item Verification of Necessity of Equivalent Gravity in Telexistence With Scale Conversion for Utilization of Humanoid Small Robot(The Eurographics Association, 2018) Matsumoto, Kohei; Furukawa, Masahiro; Wada, Kosuke; Kurokawa, Masataka; Miyamoto, Hiroki; Maeda, Taro; Bruder, Gerd and Yoshimoto, Shunsuke and Cobb, SueAccording to the concept of telexistence, even telexistence with scale conversion requires control of a robot to maintain the same attitude as that of the operator. However, a mismatch arises between the posture of a person and that of a robot because gravity between the operator and the robot is not subjectively equivalent. Our previous research demonstrated the motion of standing from a sitting position in telexistence with scale conversion using a dynamic control method, which can subjectively achieve the equivalent gravity condition between operator and robot. Acceleration in the forward direction is required to move from a standing position to walking at a constant speed. However, the moment compensation device does not consider the motion that produces acceleration in the forward direction. In this research, we achieve the equivalent gravity state without using a moment compensation device and verify the feasibility of generating walking motion from a standing position.Item Materiality Manipulation by Light-Field Projection from Reflectance Analysis(The Eurographics Association, 2018) Murakami, Kouki; Amano, Toshiyuki; Bruder, Gerd and Yoshimoto, Shunsuke and Cobb, SueIn this paper, we report a method for changing the appearance of an object to different colors as a function of viewing perspective with multiple projectors and cameras. If such appearance manipulation becomes possible, morpho butterfly colors, metallic reflection, and other structural colors can be expressed. For such appearance editing, we proposed a reflection model which describes the optical response of projectors and cameras. We also propose methods for calculating the reflectance matrix and the optimized projection images using non-negative minimization. Through experimental results, we confirmed our method allowed perspective-dependent appearance to be designed by choosing the appropriate reflectance from the non-Lambert reflection area.Item Individualized Calibration of Rotation Gain Thresholds for Redirected Walking(The Eurographics Association, 2018) Hutton, Courtney; Ziccardi, Shelby; Medina, Julio; Rosenberg, Evan Suma; Bruder, Gerd and Yoshimoto, Shunsuke and Cobb, SueRedirected walking allows the exploration of large virtual environments within a limited physical space. To achieve this, redirected walking algorithms must maximize the rotation gains applied while remaining imperceptible to the user. Previous research has established population averages for redirection thresholds, including rotation gains. However, these averages do not account for individual variation in tolerance of and susceptibility to redirection. This paper investigates methodologies designed to quickly and accurately calculate rotation gain thresholds for an individual user. This new method is straightforward to implement, requires a minimal amount of space, and takes only a few minutes to estimate a user's personal threshold for rotation gains. Results from a user study support the wide variability in detection thresholds and indicate that the method of parameter estimation through sequential testing (PEST) is viable for efficiently calibrating individual thresholds.Item Error Correction in Redirection: Rotational Manipulation for Natural Walking and Control of Walking Paths(The Eurographics Association, 2018) Mizutani, Junya; Matsumoto, Keigo; Nagao, Ryohei; Narumi, Takuji; Tanikawa, Tomohiro; Hirose, Michitaka; Bruder, Gerd and Yoshimoto, Shunsuke and Cobb, SueThis study proposes a novel rotational manipulation method for redirection when users attempt to turn around a corner within a virtual environment. The basic manipulation of conventional redirection can be classified into translational, rotational, and curvature manipulations. In conventional rotational manipulation, users must stop and rotate. However, this behavior is not natural in everyday walking. In addition, because the manipulated rotation varies depending on the amount of the user's rotation, this manipulated rotation could differ from the assumed rotation if the user does not rotate by the assumed angle during this manipulation. Correspondingly, the actual walking path may deviate from the planned path. Misalignment of the walking path may cause a deviation in the interaction with an object in real space, thus resulting in collision with real-space objects and other users. We devised a basic manipulation of redirection and formulated a novel method for manipulating the amount of rotation when users rotate while moving. Using this method, we changed the axis of rotational manipulation for preventing mismatches between real and virtual environments, and set an area to correct the error in rotational manipulation. The results of our experiments demonstrated that it is possible to control the walking paths and manipulate the amount of rotation during movement without changing the amount of rotation perceived by users, and without increasing discomfort. The results demonstrated that our method is useful for manipulating the viewpoint when a user walks naturally.Item Usability of Augmented Reality in Aeronautic Maintenance, Repair and Overhaul(The Eurographics Association, 2018) Fischini, Antoine; Ababsa, Fakhreddine; Grasser, Mickaël; Bruder, Gerd and Yoshimoto, Shunsuke and Cobb, SueAugmented Reality (AR) is a strong growing research topic in several areas including industry, training, art and entertainment. AR can help users to achieve very complex tasks by enhancing their vision with useful and well-adapted information. This paper deals with evaluating the usability of AR in aeronautic maintenance training tasks. A case study in the on-site maintenance department was conducted using an augmented reality application, involving operators at several levels of expertise. Obtained results highlighted the full efficacy of AR in the field of aeronautic maintenance.Item A Touch Panel for Presenting Softness with Visuo-Haptic Interaction(The Eurographics Association, 2018) Murata, Karen A.; Oishi, Erika; Nakamura, Takuto; Kajimoto, Hiroyuki; Tanaka, Nobuya; Sano, Takahiro; Naya, Masayuki; Bruder, Gerd and Yoshimoto, Shunsuke and Cobb, SueThis paper proposes a system capable of presenting softness using a touch panel. Many studies of touch panel-based haptic displays have developed methods for manipulating macro-roughness (shape), fine-roughness (texture), and friction. On the contrary, few studies have examined the sensation of softness. One reason for this is that to represent the spring constant of the object material, it becomes necessary to present a reaction force in the vertical direction, and this requires a large-scale device to move the surface up and down, or a device attached to the finger, both of which degrade the touch panel experience. To tackle this issue, we propose and have developed a system that can express softness not only visually but also haptically using a motor-driven film covering the touch panel to present a tangential force to the finger and with a simple visual shadow effect. In addition, we used the system to evaluate the subjective softness and confirmed the visual and haptic modulation with a realistic 3D image and a 2D image.Item Analysis of Spatio-temporal Data in Virtual Historic Spaces(The Eurographics Association, 2018) Artopoulos, Georgios; Charalambous, Panayiotis; Bruder, Gerd and Yoshimoto, Shunsuke and Cobb, SueThis paper presents a virtual reality workflow for citizen engagement in the management of neglected historic sites in contested cities, such as Nicosia, Cyprus, the last divided capital of Europe. It is contextualized in an ongoing research for the use of interactive visualization technologies for co-creation and co-management design practices in public space management. We demonstrate initial results from tracking the movement and gaze of users in VR walkthroughs of a historic site with and without user driven interventions and discuss on future directions.Item A Novel Approach for Cooperative Motion Capture (COMOCAP)(The Eurographics Association, 2018) Welch, Gregory; Wang, Tianren; Bishop, Gary; Bruder, Gerd; Bruder, Gerd and Yoshimoto, Shunsuke and Cobb, SueConventional motion capture (MOCAP) systems, e.g., optical systems, typically perform well for one person, but less so for multiple people in close proximity. Measurement quality can decline with distance, and even drop out as source/sensor components are occluded by nearby people. Furthermore, conventional optical MOCAP systems estimate body posture using a global estimation approach employing cameras that are fixed in the environment, typically at a distance such that one person or object can easily occlude another, and the relative error between tracked objects in the scene can increase as they move farther from the cameras and/or closer to each other. Body-relative tracking approaches use body-worn sensors and/or sources to track limbs with respect to the head or torso, for example, taking advantage of the proximity of limbs to the body. We present a novel approach to MOCAP that combines and extends conventional global and body-relative approaches by distributing both sensing and active signaling over each person's body to facilitate body-relative (intra-user) MOCAP for one person and body-body (inter-user) MOCAP for multiple people, in an approach we call cooperative motion capture (COMOCAP). We support the validity of the approach with simulation results from a system comprised of acoustic transceivers (receiver-transmitter units) that provide inter-transceiver range measurements. Optical, magnetic, and other types of transceivers could also be used. Our simulations demonstrate the advantages of this approach to effectively improve accuracy and robustness to occlusions in situations of close proximity between multiple persons.Item Geometrical Algorithms for Real Time Sound Rendering Using Intelligent Prioritization(The Eurographics Association, 2018) Charalampous, Panagiotis; Michael-Grigoriou, Despina; Bruder, Gerd and Yoshimoto, Shunsuke and Cobb, SueGeometrical algorithms have been the main subject of research in the field of real time sound rendering. These algorithms are variants of the image source and ray tracing algorithms, enhanced with improvements that speed up substantially their performance. The fundamental concepts behind the improvements achieved up to now was the reduction of the processed information and the acceleration of the actual processing. In this paper, we show how altering the traversal method affects significantly the algorithm's performance. These optimizations alter its behavior, providing better results for real time purposes. We separate the techniques into three major categories and we propose a stochastic Monte Carlo algorithm which involves optimizations based on prioritization.Item Frontmatter: ICAT-EGVE 2018 - International Conference on Artificial Reality and Telexistence and Eurographics Symposium on Virtual Environments(The Eurographics Association, 2018) Bruder, Gerd; Yoshimoto, Shunsuke; Cobb, Sue; Bruder, Gerd and Yoshimoto, Shunsuke and Cobb, SueItem AR based Self-sports Learning System using Decayed Dynamic TimeWarping Algorithm(The Eurographics Association, 2018) Ikeda, Atsuki; Hwang, Dong Hyun; Koike, Hideki; Bruder, Gerd and Yoshimoto, Shunsuke and Cobb, SueA self-sports learning system that provides users with real-time multimodal feedback about differences between a user's motion and an expert's motion is proposed. We also propose the Decayed Dynamic Time Warping algorithm, which allows the user to change the motion speed dynamically and repeat a target motion without additional operations. The user can thus imitate an expert's motion conveniently and accurately. The proposed system involves training and replay modes. In the training mode, the system provides audio-visual feedback to help the user imitate the expert's motion. The replay mode allows the user to compare their motion to that of the expert. An augmented reality head-mounted display delivers feedback and provides an immersive three-dimensional training experience.Item HTC Vive Pro Time Performance Benchmark for Scientific Research(The Eurographics Association, 2018) Chénéchal, Morgan Le; Goldman, Jonas Chatel; Bruder, Gerd and Yoshimoto, Shunsuke and Cobb, SueWidespread availability of consumer-level virtual reality (VR) devices creates a venue for their massive use in psychology and neuroscience research. The application of VR to scientific research however poses significant constraints on system performance and stability. In particular, studies with multimodal measurement of human behavior and physiology require precise hardwaresoftware synchronization with precise event labeling (within 10 milliseconds). Previous works investigating suitability of VR systems for research have mainly focused on benchmarking performance in spatial tracking. Therefore, it remains unclear if timing parameters such as latency or jitter in VR motion capture and VR audiovisual stimulation allow for carrying out science under strong time constraints. Here we present the first quantitative test of time performance in VR input and VR feedback of the current state-of-the-art HTC Vive Pro system. Using both low-level Python-based API and a high-level game engine (Unity), our multilevel testing procedure allows us to isolate software influence on observed results. We report that, in both test conditions, latencies are non-negligible considering fine synchronization with multimodal measurements; however, jitters are stable and low, which allows to counter-balance the effect of latency by using constant offsets to re-synchronize multimodal data. Finally, we plan to share our testing hardware setup as an open-source and low-cost benchmark toolkit, allowing objective testing to be easily reproduced by the community in an open collaborative framework.Item Safe Walking Zones: Visual Guidance for Redirected Walking in Confined Real-World Spaces(The Eurographics Association, 2018) Lubos, Paul; Bruder, Gerd; Steinicke, Frank; Bruder, Gerd and Yoshimoto, Shunsuke and Cobb, SueWalking is usually considered the most natural form of self-motion in a virtual environment (VE). However, the confined physical workspace of typical virtual reality (VR) labs often prevents natural exploration of larger VEs. Redirected walking (RDW) has been introduced as a potential solution to this restriction, but corresponding techniques often induce enormous manipulations if the workspace is considerably small and lack natural experiences therefore. In this paper we propose a user interface approach that supports natural walking in a potentially infinite virtual scene while confined to a considerably restricted physical workspace. This virtual locomotion technique relies on a safety volume, which is displayed as a semi-transparent half-capsule, inside which the user can walk without manipulations caused by RDW. We designed a circular redirection approach when the user leaves this safety volume that is complemented by a deterrent approach for user guidance outside the safety volume. We discuss in detail the process of transferring user movements inside these regions to the virtual camera in order to enable walking between points of interest in VEs, and we present the results of a usability study in which we evaluate the approach.Item A Scoping Review Exploring the Feasibility of Virtual Reality Technology Use with Individuals Living with Dementia(The Eurographics Association, 2018) Rose, Vienna; Stewart, Inga; Jenkins, Keith G.; Ang, Chee Siang; Matsangidou, Maria; Bruder, Gerd and Yoshimoto, Shunsuke and Cobb, SueThe existing evidence base in relation to the feasibility of using Virtual Reality technology systems with individuals living with a dementia appeared limited and was therefore explored. The research was collected and reviewed in terms of the different types of Virtual Reality systems (equipment and levels of immersion) and feasibility of the technology within different stages of demen-tia as well as the methodological limitations. A systematic search of the literature was conducted using the healthcare databases advanced search (Medline, PsychINFO, and EMBASE) and snowballing methods. The participants had a dementia diagnosis and the feasibility of Virtual Reality in terms of its acceptability and practicality was discussed. Only five articles met the eligibility criteria. Four included semi-immersive Virtual Reality with participants in the early stages of dementia. One included fully-immersive Virtual Reality where dementia stage ranged from 'mild' to 'severe'. Based on available demographic information, study participants resided in residential care homes, alone in the community or with their spouse. The existing literature sug-gests that both semi and fully-immersive Virtual Reality technology use can be feasible amongst individuals living within the ear-lier stages of dementia outside of a hospital environment, with it being viewed as a welcomed distraction that increased alert-ness and pleasure. However, Virtual Reality was also found to increase fear and anxiety in one study, raising important ethical implications around the safety of the user. The current evidence-base leaves a predominant gap in Virtual Reality technology system use for people within the moderate to later stages of dementia and those living in a hospital environment.Item Blowing in the Wind: Increasing Copresence with a Virtual Human via Airflow Influence in Augmented Reality(The Eurographics Association, 2018) Kim, Kangsoo; Bruder, Gerd; Welch, Gregory; Bruder, Gerd and Yoshimoto, Shunsuke and Cobb, SueIn a social context where two or more interlocutors interact with each other in the same space, one's sense of copresence with the others is an important factor for the quality of communication and engagement in the interaction. Although augmented reality (AR) technology enables the superposition of virtual humans (VHs) as interlocutors in the real world, the resulting sense of copresence is usually far lower than with a real human interlocutor. In this paper, we describe a human-subject study in which we explored and investigated the effects that subtle multi-modal interaction between the virtual environment and the real world, where a VH and human participants were co-located, can have on copresence. We compared two levels of gradually increased multi-modal interaction: (i) virtual objects being affected by real airflow as commonly experienced with fans in summer, and (ii) a VH showing awareness of this airflow. We chose airflow as one example of an environmental factor that can noticeably affect both the real and virtual worlds, and also cause subtle responses in interlocutors.We hypothesized that our two levels of treatment would increase the sense of being together with the VH gradually, i.e., participants would report higher copresence with airflow influence than without it, and the copresence would be even higher when the VH shows awareness of the airflow. The statistical analysis with the participant-reported copresence scores showed that there was an improvement of the perceived copresence with the VH when both the physical-virtual interactivity via airflow and the VH's awareness behaviors were present together. As the considered environmental factors are directed at the VH, i.e., they are not part of the direct interaction with the real human, they can provide a reasonably generalizable approach to support copresence in AR beyond the particular use case in the present experiment.Item A Study on AR Authoring using Mobile Devices for Educators(The Eurographics Association, 2018) Chu, Kinfung; Lu, Weiquan; Oka, Kiyoshi; Takashima, Kazuki; Kitamura, Yoshifumi; Bruder, Gerd and Yoshimoto, Shunsuke and Cobb, SueAugmented Reality (AR) on consumer devices is now commonplace and it finds application in areas like online retail and gaming. Among which, school education can especially benefit from the interactivity and expressiveness provided by AR technology, facilitating the learning process of students. Although AR-enabled hardware and applications are becoming increasingly accessible to both students and teachers, the entry requirement for AR authoring is still prohibitively high for school teachers. Given the vast variation in the learning ability of students and school curricula, an AR authoring tool that allows the rapid and easy creation of educational content seems to be very desirable among teachers. This paper proposes a gesture-based control method that satisfies the need of educational AR authoring and presents prototypes that work well with smartphone VR head mounts. Through user studies we show that our proposed control method is simple but effective for basic authoring tasks. Our prototypes are also found to be useful in teaching different concepts that require a high degree of spatial comprehension.Item Compression Of 16K Video For Mobile VR Playback Over 4K Streams(The Eurographics Association, 2018) Vazquez, Iker; Cutchin, Steve; Bruder, Gerd and Yoshimoto, Shunsuke and Cobb, SueMobile virtual reality headset devices are currently constrained to playing back 4K video streams for hardware, network, and performance reasons. This strongly limits the quality of 360 degrees videos over 4K streams; which in turn translates to insufficient resolution for virtual reality video playback. Spherical stereo virtual reality videos can be currently captured at 8K and 16K resolutions, with 8K being the minimal resolution for an acceptable quality video playback experience. In this paper, we present a novel technique that uses object tracking to compress 16K spherical stereo videos captured by a still camera into a format that can be streamed over 4K channels while maintaining the 16K video resolution for typical video captures.