PHYSICAL ACTIVITY IN VIRTUAL REALITY

The purpose of this conference is to discuss about research on human physical activity based on Virtual Reality (VR). VR 1) offers a unique compromise between control and ecological property of the studied situation, 2) enables to enrich/modify the physical environment, 3) provides control on the multisensory feedback given to the user, 4) and has the potential to enhance motivation and increase the number of repetition in motor skills training. Recent democratisation of immersive technologies, with the development of cheap interactive devices for videogames, has encouraged research in this domain. In this conference, we will address examples of perception-action coupling analysis based on VR, will analyse how technical choices could affect the behaviour of the studied subjects, and will expose perspectives in motor skills training based on VR

Paralympic VR: an immersive experience

Paralympic VR: an immersive experience is based on exploratory research and consists in the production of a 360 video-prototype that aims to give special access to the wheelchair basketball training universe, bringing the users close to Paralympic athletes without the need to hide the impairment or hyper focus on the stories behind the disability. Media coverage of Paralympic sports and the representation of disabled athletes have been changing, but still present a medicalised framing, a narrative where the athletes are commonly portrayed as heroes due to the overcoming of difficulties related to the impairment and not to the sports results. This present project work considers immersive journalism and the use of virtual reality technologies as the means by which an alternative approach and a better representation of Paralympians are possible. The project presents the description of the workflow process, detailing conceptualization decisions, technical aspects and, mainly, the challenges and lessons learned. A user study combining focus groups and online survey was also conducted in order to have insights about the experience of watching the video with the headset Samsung Gear VR. Feedback provided by participants indicated that the prototype accomplished its aim. Recommendations to improve future work were also gathered.Paralympic VR: an immersive experience baseia-se em investigação exploratória e consiste na produção de um vídeo 360 graus que visa dar acesso especial ao universo de treino do basquete em cadeira de rodas, aproximando os utilizadores dos atletas paralímpicos sem a necessidade de ocultar a deficiência ou dar grande enfoque às histórias por detrás da deficiência. A cobertura do desporto paralímpico nos media e a representação dos atletas com deficiência está a transformar-se, mas ainda apresenta uma abordagem medicalizada, uma narrativa em que os atletas são comumente retratados como heróis devido à superação de dificuldades relacionadas à deficiência e não em virtude aos resultados desportivos. O jornalismo imersivo e o uso de tecnologias de realidade virtual são considerados no presente trabalho de projeto os meios pelos quais é possível uma abordagem alternativa e uma melhor representação dos atletas paralímpicos. O projeto apresenta a descrição de todo o processo de produção do vídeo-protótipo, detalhando decisões de conceito, aspectos técnicos e, principalmente, os desafios e lições aprendidas. Um estudo com utilizadores combinando grupos de foco e questionário on-line também foi conduzido para a recolha de perceções sobre a experiência de assistir ao vídeo com o headset Samsung Gear VR. Os comentários fornecidos pelos participantes indicaram que o protótipo atingiu seu objetivo. Importantes recomendações para a melhoria de futuras experiências também foram reunidas

VIRTUAL REALITY & SPORT

This applied session deals with the design of immersive environments for human motion performance analysis. In a first part of the session, a theoretical presentation describes the aims and scopes of such type of experiments. In a second part of the session, a review of the available immersive systems will be exposed. Finally, a practical framework will be designed in real-time with the attendees: a low-cost immersive environment based on a Microsoft Kinect, a Razer Hydra and an Oculus Rift Head Mounted Display device. We will develop an experiment to analyse perception-action coupling in soccer with simulated virtual opponents enabling to analyse the decision-making of a real goalkeeper

Paralympic VR Game Immersive Game using Virtual Reality Technology

Throughout the years virtual reality has been used for a wide range of applications, and several types of research have been made in order to improve its techniques and technology. In the last few years, the interest in virtual reality has been increasing partially due to the emergence of cheaper and more accessible hardware, and the increase in content available. One of the possible applications for virtual reality is to lead people into seeing situations from a different perspective, which can help change opinions. This thesis uses virtual reality to help people better understand paralympic sports by allowing them to experience the sports’ world from the athletes’ perspective. For the creation of the virtual environment, both computer-generated elements and 360 video are used. The integration of these two components presented a challenge to explore. This thesis focused on wheelchair basketball, and a simulator of this sport was created resorting to the use of a game engine (Unity 3D). For the development of this simulator, computer-generated elements were built, and the interaction with them implemented. Besides allowing the users to play the sport as if they are in the athlete’s shoes, users can also watch 360 videos in which explanations of the modality (rules and classification) are presented. They are also capable of interacting with some of these videos through virtual elements that are placed over the videos. User studies were conducted to evaluate the sense of presence, motion sickness and usability of the system developed. The results were positive although there are still some aspects that should be improved

Analyzing the Impact of Spatio-Temporal Sensor Resolution on Player Experience in Augmented Reality Games

Along with automating everyday tasks of human life, smartphones have become one of the most popular devices to play video games on due to their interactivity. Smartphones are embedded with various sensors which enhance their ability to adopt new new interaction techniques for video games. These integrated sen- sors, such as motion sensors or location sensors, make the device able to adopt new interaction techniques that enhance usability. However, despite their mobility and embedded sensor capacity, smartphones are limited in processing power and display area compared to desktop computer consoles. When it comes to evaluat- ing Player Experience (PX), players might not have as compelling an experience because the rich graphics environments that a desktop computer can provide are absent on a smartphone. A plausible alternative in this regard can be substituting the virtual game world with a real world game board, perceived through the device camera by rendering the digital artifacts over the camera view. This technology is widely known as Augmented Reality (AR). Smartphone sensors (e.g. GPS, accelerometer, gyro-meter, compass) have enhanced the capability for deploying Augmented Reality technology. AR has been applied to a large number of smartphone games including shooters, casual games, or puzzles. Because AR play environments are viewed through the camera, rendering the digital artifacts consistently and accurately is crucial because the digital characters need to move with respect to sensed orientation, then the accelerometer and gyroscope need to provide su ciently accurate and precise readings to make the game playable. In particular, determining the pose of the camera in space is vital as the appropriate angle to view the rendered digital characters are determined by the pose of the camera. This defines how well the players will be able interact with the digital game characters. Depending in the Quality of Service (QoS) of these sensors, the Player Experience (PX) may vary as the rendering of digital characters are affected by noisy sensors causing a loss of registration. Confronting such problem while developing AR games is di cult in general as it requires creating wide variety of game types, narratives, input modalities as well as user-testing. Moreover, current AR games developers do not have any specific guidelines for developing AR games, and concrete guidelines outlining the tradeoffs between QoS and PX for different genres and interaction techniques are required. My dissertation provides a complete view (a taxonomy) of the spatio-temporal sensor resolution depen- dency of the existing AR games. Four user experiments have been conducted and one experiment is proposed to validate the taxonomy and demonstrate the differential impact of sensor noise on gameplay of different genres of AR games in different aspect of PX. This analysis is performed in the context of a novel instru- mentation technology, which allows the controlled manipulation of QoS on position and orientation sensors. The experimental outcome demonstrated how the QoS of input sensor noise impacts the PX differently while playing AR game of different genre and the key elements creating this differential impact are - the input modality, narrative and game mechanics. Later, concrete guidelines are derived to regulate the sensor QoS as complete set of instructions to develop different genres or AR games

Effect of avatars and viewpoints on performance in virtual world: efficiency vs. telepresence

An increasing number of our interactions are mediated through e-technologies. In order to enhance the human’s feeling of presence into these virtual environments, also known as telepresence, the individual is usually embodied into an avatar. The natural adaptation capabilities, underlain by the plasticity of the body schema, of the human being make a body ownership of the avatar possible, in which the user feels more like his/her virtual alter ego than himself/herself. However, this phenomenon only occurs under specific conditions. Two experiments are designed to study the human’s feeling and performance according to a scale of natural relationship between the participant and the avatar. In both experiments, the human-avatar interaction is carried out by a Natural User Interface (NUI) and the individual’s performance is assessed through a behavioural index, based on the concept of affordances, and a questionnaire of presence The first experiment shows that the feeling of telepresence and ownership seem to be greater when the avatar’s kinematics and proportions are close to those of the user. However, the efficiency to complete the task is higher for a more mechanical and stereotypical avatar. The second experiment shows that the manipulation of the viewpoint induces a similar difference across the sessions. Results are discussed in terms of the neurobehavioral processes underlying performance in virtual worlds, which seem to be based on ownership when the virtual artefact ensures a preservation of sensorimotor contingencies, and simple geometrical mapping when the conditions become more artificial

Eye quietness and quiet eye in expert and novice golf performance: an electrooculographic analysis

Quiet eye (QE) is the final ocular fixation on the target of an action (e.g., the ball in golf putting). Camerabased eye-tracking studies have consistently found longer QE durations in experts than novices; however, mechanisms underlying QE are not known. To offer a new perspective we examined the feasibility of measuring the QE using electrooculography (EOG) and developed an index to assess ocular activity across time: eye quietness (EQ). Ten expert and ten novice golfers putted 60 balls to a 2.4 m distant hole. Horizontal EOG (2ms resolution) was recorded from two electrodes placed on the outer sides of the eyes. QE duration was measured using a EOG voltage threshold and comprised the sum of the pre-movement and post-movement initiation components. EQ was computed as the standard deviation of the EOG in 0.5 s bins from –4 to +2 s, relative to backswing initiation: lower values indicate less movement of the eyes, hence greater quietness. Finally, we measured club-ball address and swing durations. T-tests showed that total QE did not differ between groups (p = .31); however, experts had marginally shorter pre-movement QE (p = .08) and longer post-movement QE (p < .001) than novices. A group × time ANOVA revealed that experts had less EQ before backswing initiation and greater EQ after backswing initiation (p = .002). QE durations were inversely correlated with EQ from –1.5 to 1 s (rs = –.48 - –.90, ps = .03 - .001). Experts had longer swing durations than novices (p = .01) and, importantly, swing durations correlated positively with post-movement QE (r = .52, p = .02) and negatively with EQ from 0.5 to 1s (r = –.63, p = .003). This study demonstrates the feasibility of measuring ocular activity using EOG and validates EQ as an index of ocular activity. Its findings challenge the dominant perspective on QE and provide new evidence that expert-novice differences in ocular activity may reflect differences in the kinematics of how experts and novices execute skills

Interfaces for human-centered production and use of computer graphics assets

L'abstract è presente nell'allegato / the abstract is in the attachmen

Gyroscope induced force feedback for ball impact simulation in exergames.

A haptic feedback device for simulating batting sport haptics was designed using the resultant gyroscopic effect from rapidly reorienting spinning flywheels and integrated into a custom cricket themed virtual reality exergame. The device was capable of producing impact vibrations and a 0.1 N m torque. A within-subjects user study conducted on 16 participants, and player presence was evaluated using the Presence Questionnaire. The results of the user study were statistically insignificant due to a small sample size (p=0.153), and we were unable to reject the null hypothesis, but visual data analysis was used to identify trends that supported our hypothesis that increase haptic feedback fidelity increases presence in virtual reality batting sports exergames. Due to the statistical insignificance of these results, further research should be conducted to confirm these findings

Development of the Virtual Taekwondo Training Environment Prototype for Self-Directed Taekwondo Training

Taekwondo is a martial art that has been practised by over 50 million people all over the world, and this number is increasing which makes Taekwondo more popular. Normally, Taekwondo training is conducted in a hall or large open spaces in the presence of a trainer. However, this approach has some limitations in supporting self-directed training. Even though there are several supplementary materials for Taekwondo training, they have many limitations. This paper introduces Virtual Reality and Motion Capture technologies as an alternative to the existing Taekwondo training approaches. The main advantage of these technologies for self-directed training is that they are able to imitate the trainer’s movement and provide three-dimensional displays of body movements which can be viewed from any angles. This enables the trainees to understand and follow the movements without assistance from the real trainer. This paper presents the design and development of the Virtual Taekwondo Training prototype as supplementary material for self-directed Taekwondo training based on Virtual Reality and Motion Capture technologies. This prototype aims to provide a new approach to supplementary material that can provide trainees’ satisfaction while doing selfdirected Taekwondo training