Since the popularisation of the Internet in the 1990s, the cyberspace has kept evolving. We have created various computer-mediated virtual environments including social networks, video conferencing, virtual 3D worlds (e.g., VR Chat), augmented reality applications (e.g., Pokemon Go), and Non-Fungible Token Games (e.g., Upland). Such virtual environments, albeit non-perpetual and unconnected, have bought us various degrees of digital transformation. The term `metaverse' has been coined to further facilitate the digital transformation in every aspect of our physical lives. At the core of the metaverse stands the vision of an immersive Internet as a gigantic, unified, persistent, and shared realm. While the metaverse may seem futuristic, catalysed by emerging technologies such as Extended Reality, 5G, and Artificial Intelligence, the digital `big bang' of our cyberspace is not far away. This survey paper presents the first effort to offer a comprehensive framework that examines the latest metaverse development under the dimensions of state-of-the-art technologies and metaverse ecosystems, and illustrates the possibility of the digital `big bang'. First, technologies are the enablers that drive the transition from the current Internet to the metaverse. We thus examine eight enabling technologies rigorously - Extended Reality, User Interactivity (Human-Computer Interaction), Artificial Intelligence, Blockchain, Computer Vision, IoT and Robotics, Edge and Cloud computing, and Future Mobile Networks. In terms of applications, the metaverse ecosystem allows human users to live and play within a self-sustaining, persistent, and shared realm. Therefore, we discuss six user-centric factors -- Avatar, Content Creation, Virtual Economy, Social Acceptability, Security and Privacy, and Trust and Accountability. Finally, we propose a concrete research agenda for the development of the metaverse.

All One Needs to Know about Metaverse: A Complete Survey on Technological Singularity, Virtual Ecosystem, and Research Agenda

Cybersickness provoked by head-mounted display affects cutaneous vascular tone, heart rate and reaction time.

With the development of 3D displays, user's eye fatigue has been an important issue when viewing these displays. There have been previous studies conducted on eye fatigue related to 3D display use, however, most of these have employed a limited number of modalities for measurements, such as electroencephalograms (EEGs), biomedical signals, and eye responses. In this paper, we propose a new assessment of eye fatigue related to 3D display use based on multimodal measurements. compared to previous works Our research is novel in the following four ways: first, to enhance the accuracy of assessment of eye fatigue, we measure EEG signals, eye blinking rate (BR), facial temperature (FT), and a subjective evaluation (SE) score before and after a user watches a 3D display; second, in order to accurately measure BR in a manner that is convenient for the user, we implement a remote gaze-tracking system using a high speed (mega-pixel) camera that measures eye blinks of both eyes; thirdly, changes in the FT are measured using a remote thermal camera, which can enhance the measurement of eye fatigue, and fourth, we perform various statistical analyses to evaluate the correlation between the EEG signal, eye BR, FT, and the SE score based on the T-test, correlation matrix, and effect size. Results show that the correlation of the SE with other data (FT, BR, and EEG) is the highest, while those of the FT, BR, and EEG with other data are second, third, and fourth highest, respectively.

https://www.mdpi.com/1424-8220/14/9/16467/pdf

Assessment of Eye Fatigue Caused by 3D Displays Based on Multimodal Measurements

Communications in Computer and Information Science

Three-dimensional (3D) display systems are widely used nowadays, and their psychophysiological effects on human health have been investigated in detail. However, due to recent advances in 3D display technology, such as (super) multiview display or holography, there is a clear and pressing need to develop a new measurement method for determining optimal viewing parameters. Depending on the display system in question, virtual objects with depth information may present different properties to the human visual system and thus are perceived differently. The methods to measure the factors that affect human health in 3D displays need to be thoroughly reviewed in order to further investigate these characteristics and determine optimal viewing parameters. In this paper, we review various measurement methods that have been proposed to examine the effects of 3D stimuli on the human visual system. We provide an overview of recent advances in 3D techniques by relating them with human factors, primarily focusing on subjective and objective measurement methods, to ensure that human-friendly 3D content and displays will benefit from recent technical advances.

Overview of Measurement Methods for Factors Affecting the Human Visual System in 3D Displays

Does visual fatigue from 3D displays affect autonomic regulation and heart rhythm

Evaluation of 3D cognitive fatigue using heart-brain synchronization.

Non-contact measurement of heart response reflected in human eye.

The eyes of a virtual human avatar are the fundamental means for communicating language and affective feelings in a virtual environment. For this purpose, this study evaluates user's visual feeling according to the changes pupillary responses based on the heart rate for a representing a human avatar; this is considered as a new factor for representing a realistic avatar. We construct a human avatar in which the pupillary response is delivered real-time based on the heart rate. The results can be regarded as the basis for designing a realistic human avatar system by supporting a new visual realistic representing factor.

Development of Realistic Digital Expression of Human Avatars through Pupillary Responses based on Heart Rate

In the VnR (Virtual and Real Worlds) of recent virtual reality convergence, the modelling of realistic human face is focused on the facial appearance such as the shape of facial parts and muscle movement. However, the facial changing parameters caused by environmental factors beyond the facial appearance factors can be regarded as important ones in terms of effectively representing virtual avatar. Therefore, this study evaluates user`s visual feeling response according to the opacity variation of eye reflection of virtual avatar which is considered as a new parameter for reprenting realistic avatar. Experimental result showed that more clear eye reflection induced more realistic visual feeling of subjects. This result can be regarded as a basis for designing realistic virtual avatar by supporting a new visual realistic representing factor (eye reflection) and its degree of representation (reflectance ratio).

https://www.koreascience.kr:443/article/JAKO201325954481064.pdf

Myoung Ju Won

Papers

Does visual fatigue from 3D displays affect autonomic regulation and heart rhythm

Evaluation of 3D cognitive fatigue using heart-brain synchronization.

Non-contact measurement of heart response reflected in human eye.

Development of Realistic Digital Expression of Human Avatars through Pupillary Responses based on Heart Rate

Realistic Expression Factor to Visual Presence of Virtual Avatar in Eye Reflection