ICAT-EGVE2014

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https://diglib.eg.org/handle/10.2312/7758

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Beyond Post-It: Structured Multimedia Annotations for Collaborative VEs
(The Eurographics Association, 2014) Guerreiro, Joao; Medeiros, Daniel; Mendes, Daniel; Sousa, Mauricio; Jorge, Joaquim; Raposo, Alberto; Santos, Ismael; Takuya Nojima and Dirk Reiners and Oliver Staadt
Globalization has transformed engineering design into a world-wide endeavor pursued by geographically distributed specialist teams. Widespread adoption of VR for design and the need to act and place marks directly on the objects of discussion in design reviewing tasks led to research on annotations in virtual collaborative environments. However, conventional approaches have yet to progress beyond the yellow postit + text metaphor. Indeed, multimedia such as audio, sketches, video and animations afford greater expressiveness which could be put to good use in collaborative environments. Furthermore, individual annotations fail to capture both the rationale and flow of discussion which are key to understanding project design decisions. One exemplar instance is offshore engineering projects that normally engage geographically distributed highly-specialized engineering teams and require both improved productivity, due to project costs and the need to reducing risks when reviewing designs of deep-water oil & gas platforms. In this paper, we present an approach to rich, structured multimedia annotations to support the discussion and decision making in design reviewing tasks. Furthermore, our approach supports issue-based argumentation to reveal provenance of design decisions to better support the workflow in engineering projects. While this is an initial exploration of the solution space, examples show greater support of collaborative design review over traditional approaches.
The Effects of Avatars on Presence in Virtual Environments for Persons with Mobility Impairments
(The Eurographics Association, 2014) Guo, Rongkai; Samaraweera, Gayani; Quarles, John; Takuya Nojima and Dirk Reiners and Oliver Staadt
The main question we ask is: How do avatars affect presence specifically for Persons with Mobility Impairments (PMIs)? For example, PMIs' deficits in the proprioceptive sense could affect their body perception in immersive virtual reality, which could impact presence. To investigate this we replicated the classic virtual pit experiment and included a responsive full body avatar (or lack thereof) as a 3D user interface. We recruited from two different populations: 11 PMIs and another 11 Persons without Mobility Impairments (PNMIs) as a control. Each PNMI was matched to a PMI based on age, weight, height, and prior VE exposure. Results of this study indicate that avatars elicit a higher sense of presence for PMIs than for PNMIs. In addition, results suggest that PMIs are easier to immerse in VEs than PNMIs, which may further motivate the future use of VE technology for PMIs.
Interpretation of Tactile Sensation using an Anthropomorphic Finger Motion Interface to Operate a Virtual Avatar
(The Eurographics Association, 2014) Ujitoko, Yusuke; Hirota, Koichi; Takuya Nojima and Dirk Reiners and Oliver Staadt
The objective of the system presented in this paper is to give users tactile feedback while walking in a virtual world through an anthropomorphic finger motion interface. We determined that the synchrony between the first person perspective and proprioceptive information together with the motor activity of the user's fingers are able to induce an illusionary feeling that is equivalent to the sense of ownership of the invisible avatar's legs. Under this condition, the perception of the ground under the virtual avatar's foot is felt through the user's fingertip. The experiments indicated that using our method the scale of the tactile perception of the texture roughness was extended and that the enlargement ratio was proportional to the avatar's body (foot) size. In order to display the target tactile perception to the users, we have to control only the virtual avatar's body (foot) size and the roughness of the tactile texture. Our results suggest that in terms of tactile perception fingers can be a replacement for legs in locomotion interfaces.
Investigation of Dynamic View Expansion for Head-Mounted Displays with Head Tracking in Virtual Environments
(The Eurographics Association, 2014) Yano, Yuki; Kiyokawa, Kiyoshi; Sherstyuk, Andrei; Mashita, T.; Takemura, H.; Takuya Nojima and Dirk Reiners and Oliver Staadt
Head mounted displays (HMD) are widely used for visual immersion in virtual reality (VR) systems. It is acknowledged that the narrow field of view (FOV) for most HMD models is the leading cause of insufficient quality of immersion, resulting in suboptimal user performance in various tasks in VR and early fatigue, too. Proposed solutions to this problem range from hardware-based approaches to software enhancements of the viewing process. There exist three major techniques of view expansion; minification or rendering graphics with a larger FOV than the display's FOV, motion amplification or amplifying user head rotation aiming to provide accelerated access to peripheral vision during wide sweeping head movements, and diverging left and right virtual cameras outwards in order to increase the combined binocular FOV. Static view expansion has been reported to increase user efficiency in search and navigation tasks, however the effectiveness of dynamic view expansion is not yet well understood. When applied, view expansion techniques modify the natural viewing process and alter familiar user reflex-response loops, which may result in motion sickness and poor user performance. Thus, it is vital to evaluate dynamic view expansion techniques in terms of task effectiveness and user workload. This paper details dynamic view expansion techniques, experimental settings and findings of the user study. In the user study, we investigate three view expansion techniques, applying them dynamically based on user behaviors. We evaluate the effectiveness of these methods quantitatively, by measuring and comparing user performance and user workload in a target search task. Also, we collect and compare qualitative feedback from the subjects in the experiment. Experimental results show that certain levels of minification and motion amplification increase performance by 8.2% and 6.0%, respectively, with comparable or even decreased subjective workload.
Neural Correlates of Disrupted Presence: Strange Disruptions in a Naturalistic Virtual Environment
(The Eurographics Association, 2014) Sjoelie, Daniel; Kalpouzos, Gregoria; Eriksson, Johan; Takuya Nojima and Dirk Reiners and Oliver Staadt
The concept of presence is commonly related to whether or not a user feels, acts, and reacts as if he/she were in a real familiar environment when using a virtual reality (VR) application. Understanding the neural correlates of presence may provide a foundation for objective measurements and important constraints for theoretical explanations. Here, we focus on the importance of expectations and their violation in several theoretical descriptions of presence in order to investigate neural correlates of disrupted presence. Functional magnetic resonance imaging (fMRI) was used to measure brain activity during execution of everyday tasks in a naturalistic virtual environment (VE). Time periods with disrupted presence were identified using subject reports of strange situations, interpreted as violations of expectations related to the sense of presence. Disrupted presence was associated with increased activity in the frontopolar cortex (FPC), lateral occipito-temporal cortex (LOTC), the temporal poles (TP), and the posterior superior temporal cortex (pSTC). We relate these areas to integration of key aspects of a presence experience, relating the (changing) situation to management of task and goals (FPC), interpretation of visual input (LOTC), emotional evaluation of the context (TP) and possible interactions (pSTC). These results are consistent with an interpretation of disrupted presence as a re-evaluation of key aspects of a subjective mental reality, updating the synchronization with the virtual environment as previous predictions fail. Such a subjective mental reality may also be related to a self-centered type of mentalization, providing a link to accounts of presence building on the self.
A New Direct Manipulation Technique for Immersive 3D Virtual Environments
(The Eurographics Association, 2014) Nguyen, Thi-Thuong Huyen; Duval, Thierry; Pontonnier, Charles; Takuya Nojima and Dirk Reiners and Oliver Staadt
In this paper, we introduce a new 7-Handle manipulation technique for 3D objects in immersive virtual environments and its evaluation. The 7-Handle technique includes a set of seven points which are flexibly attached to an object. There are three different control modes for these points including configuration, manipulation and locking / unlocking modes. We have conducted an experiment to compare the efficiency of this technique with the traditional 6-DOF direct manipulation technique in terms of time, discomfort metrics and subjective estimation for precise manipulations in an immersive virtual environment in two consecutive phases: an approach phase and a refinement phase. The statistical results showed that the completion time in the approach phase of the 7-Handle technique was significantly longer than the completion time of the 6-DOF technique. Nevertheless, we found a significant interaction effect between the two factors (the manipulation technique and the object size) on the completion time of the refinement phase. In addition, even though we did not find any significant differences between the two techniques in terms of intuitiveness, ease of use and global preference in the result of subjective data, we obtained a significantly better satisfaction feedback from the subjects for the efficiency and fatigue criteria.
Pathfinder Vision: Tele-operation Robot Interface in Consideration of Geometry for Supporting Future Prediction
(The Eurographics Association, 2014) Maeda, Naoya; Morita, Jun; Sugimoto, Maki; Takuya Nojima and Dirk Reiners and Oliver Staadt
Pathfinder Vision is a visual presentation interface for remote robot operation. This interface assists operators by planning the future routes of the robot by presenting images which take into consideration the physical obstructions of the surrounding environment. We also took the occlusion of the 3D environment into account when rendering the CG model of the robot by calculating the current state and 3D geometry of the robot. By visualizing the predicted future with occlusion, our proposed methods makes it possible to prevent collisions while operating tele-operated robots. This system helps operators to find a more secure future trajectory of the robot.
Short Paper: #SEVEN, a Sensor Effector Based Scenarios Model for Driving Collaborative Virtual Environment
(The Eurographics Association, 2014) Claude, Guillaume; Gouranton, Valerie; Berthelot, Rozenn Bouville; Arnaldi, Bruno; Takuya Nojima and Dirk Reiners and Oliver Staadt
In this paper we present #SEVEN, a sensor effector model that enables the execution of complex scenarios for driving Virtual Reality applications. #SEVEN is based on an enhanced Petri net model which is able to describe and solve intricate event sequences. Our model also proposes several useful features for the design of collaborative scenarios for Collaborative Virtual Environments such as versatile roles and Activity Continuum.We also illustrate its usage it by describing a demonstrator that presents an implementation of our model.
Short Paper: A Video Self-avatar Influences the Perception of Heights in an Augmented Reality Oculus Rift
(The Eurographics Association, 2014) Gutekunst, Matthias; Geuss, Michael; Rauhoeft, Greg; Stefanucci, Jeanine; Kloos, Uwe; Mohler, Betty; Takuya Nojima and Dirk Reiners and Oliver Staadt
This paper compares the influence a video self-avatar and a lack of a visual representation of a body have on height estimation when standing at a virtual visual cliff. A height estimation experiment was conducted using a custom augmented reality Oculus Rift hardware and software prototype also described in this paper. The results show a consistency with previous research demonstrating that the presence of a visual body influences height estimates, just as it has been shown to influence distance estimates and affordance estimates.
Space-Time Maps for Virtual Environments
(The Eurographics Association, 2014) Sherstyuk, Andrei; Treskunov, Anton; Takuya Nojima and Dirk Reiners and Oliver Staadt
Terrain image maps are widely used in 3D Virtual Environments, including games, online social worlds, and Virtual Reality systems, for controlling elevation of ground-bound travelers and other moving objects. By making use of all available color channels in the terrain image, it is possible to encode important information related to travel, such as presence of obstacles, directly into the image. This information can be retrieved in real time, for collision detection and avoidance, at flat cost of accessing pixel values from the image memory. We take this idea of overloading terrain maps even further and introduce time maps, where pixels can also define the rate of time, for each player at given location. In this concept work, we present a general mechanism of encoding the rate of time into a terrain image and discuss a number of applications that may benefit from making time rate location specific. Also, we offer some insights how such space-time maps can be integrated into existing game engines.
Successive Wide Viewing Angle Appearance Manipulation with Dual Projector Camera Systems
(The Eurographics Association, 2014) Amano, Toshiyuki; Shimana, Isao; Ushida, Shun; Kono, Kunioki; Takuya Nojima and Dirk Reiners and Oliver Staadt
In this study, we investigated the use of successive omnidirectional appearance manipulation for the cooperative control of multiple projector camera systems. This type of system comprises several surrounding projector camera units, where each unit projects illumination independently onto a different aspect of a target object based on feedback from the projector cameras. Thus, the system can facilitate appearance manipulation from any viewpoint in the surrounding area. An advantage of this system is that it does not require information sharing or a geometrical model. However, this approach is problematic because the stability of the total control system cannot be guaranteed even if the feedback system of each projector camera is stable. Therefore, we simulated the feedback from the cooperative projector camera system to evaluate its stability. Based on hardware experiments, we confirmed the stability of omnidirectional appearance manipulation using two projector camera units in an interference condition. The results showed that the object's appearance could be manipulated throughout approximately 296 degrees of the total circumference of the target object.

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