2022
Authors
Goncalves, G; Melo, M; Barbosa, L; Vasconcelos Raposo, J; Bessa, M;
Publication
VIRTUAL REALITY
Abstract
The main goal of this paper is to investigate the effect of different types of self-representations through floating members (hands vs. hands + feet), virtual full body (hands + feet vs. full-body avatar), walking fidelity (static feet, simulated walking, real walking), and number of tracking points used (head + hands, head + hands + feet, head + hands + feet + hip) on the sense of presence and embodiment through questionnaires. The sample consisted of 98 participants divided into a total of six conditions in a between-subjects design. The HTC Vive headset, controllers, and trackers were used to perform the experiment. Users were tasked to find a series of hidden objects in a virtual environment and place them in a travel bag. We concluded that (1) the addition of feet to floating hands can impair the experienced realism (p = 0.039), (2) both floating members and full-body avatars can be used without affecting presence and embodiment (p > 0.05) as long as there is the same level of control over the self-representation, (3) simulated walking scores of presence and embodiment were similar when compared to static feet and real walking tracking data (p > 0.05), and (4) adding hip tracking overhead, hand and feet tracking (when using a full-body avatar) allows for a more realistic response to stimuli (p = 0.002) and a higher overall feeling of embodiment (p = 0.023).
2022
Authors
Machado, R; Rodrigues, R; Coelho, H; Melo, M; Barbosa, L; Bessa, M;
Publication
2022 INTERNATIONAL CONFERENCE ON GRAPHICS AND INTERACTION (ICGI)
Abstract
Virtual reality (VR) is still a field that is in constant development, and people are trying to use it to have a close representation of reality by creating immersive environments. However, despite the existence of some tools that have been adapted to work with VR, they require some experience to work with, and there is a considerable amount of resources that need to be spent to create and maintain the VR experiences, which prevents the adoption and use of all the benefits that VR can bring. This work proposes an architecture for an authoring tool that allows users to create their own virtual experiences without the need for an extensive understanding of it and use them to create a virtual training exercise. This paper uses a case study built upon a real training context scenario applied to the agroforestry field. To validate this proposal, a prototype was built and subject to usability and satisfaction tests that demonstrated the ease of understanding and learning of the interfaces and all the functionalities implemented.
2022
Authors
Rodrigues, P; Coelho, H; Melo, M; Bessa, M;
Publication
2022 INTERNATIONAL CONFERENCE ON GRAPHICS AND INTERACTION (ICGI)
Abstract
Virtual reality applications aimed at worker training to train professionals are more common with the virtual reality advancements observed in this day and age. More companies search for ways to improve the efficiency and efficacy of their training programs, whilst also reducing training costs. There are several training applications found in the literature, but not many focus on the theme of computer assembly, and only a few have options like an observer's menu or a scoring system. With that in mind, a training application for assembling computer towers was designed. This article will focus on the application's functionalities, the results of questionnaires made to evaluate its quality and usability and potential future work. The study realized had good results and a good, varied sample of volunteers, with a score of 93.4% in the custom-made questionnaire, a cyber-sickness (SSQ) score of 26.53%, a usability score (SUS) of 90% and a satisfaction (ASQ) score of 17.67%, being that a higher score is better in custom made and SUS questionnaires, and a lower score is better in the SSQ and ASQ questionnaires. Although this project is just a proof of concept, it focuses on a theme that will certainly be explored soon, with the rise of demand for training applications, the ever-growing gamer market, and workstations for the design of virtual reality applications, like the one described on this paper.
2023
Authors
Melo, M; Gontalves, G; Vasconcelos-Raposo, J; Bessa, M;
Publication
IEEE ACCESS
Abstract
Presence is often used to evaluate Virtual Reality (VR) applications. However, the raw scores are hard to interpret and need to be compared to other data to be meaningful. This paper leverages a database of 1909 responses to the Igroup Presence Questionnaire (IPQ) in different contexts to put forward a scale that qualitatively interprets raw Presence scores for VR experiences. The qualitative grading encompasses the acceptability dimension and analogous academic grading scales ranging from A to F and the adjective of such scores in a scale from Excellent to Unacceptable. Furthermore, the qualitative grading system encompasses Presence and its subscales Spatial Presence, Involvement, and Experienced Realism as defined by the IPQ. Adopting this grading system, supported by a robust dataset of Presence scores, enables practitioners to evaluate and interpret individual IPQ scores, allowing them to gain insights regarding the evaluated applications' effectiveness.
2024
Authors
Narciso, D; Melo, M; Rodrigues, S; Cunha, JP; Vasconcelos-Raposo, J; Bessa, M;
Publication
IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS
Abstract
How we perceive and experience the world around us is inherently multisensory. Most of the Virtual Reality (VR) literature is based on the senses of sight and hearing. However, there is a lot of potential for integrating additional stimuli into Virtual Environments (VEs), especially in a training context. Identifying the relevant stimuli for obtaining a virtual experience that is perceptually equivalent to a real experience will lead users to behave the same across environments, which adds substantial value for several training areas, such as firefighters. In this article, we present an experiment aiming to assess the impact of different sensory stimuli on stress, fatigue, cybersickness, Presence and knowledge transfer of users during a firefighter training VE. The results suggested that the stimulus that significantly impacted the user's response was wearing a firefighter's uniform and combining all sensory stimuli under study: heat, weight, uniform, and mask. The results also showed that the VE did not induce cybersickness and that it was successful in the task of transferring knowledge.
2023
Authors
Goncalves, G; Coelho, H; Monteiro, P; Melo, M; Bessa, M;
Publication
ACM COMPUTING SURVEYS
Abstract
The adoption of immersive virtual experiences (IVEs) opened new research lines where the impact of realism is being studied, allowing developers to focus resources on realism factors proven to improve the user experience the most. We analyzed papers that compared different levels of realism and evaluated their impact on user experience. Exploratorily, we also synthesized the realism terms used by authors. From 1,300 initial documents, 79 met the eligibility criteria. Overall, most of the studies reported that higher realism has a positive impact on user experience. These data allow a better understanding of realism in IVEs, guiding future R&D.
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