Abstract
Over the years, various immersive virtual training environments (iVTEs) have been developed, allowing companies to start transitioning to Virtual Reality (VR) technologies to train their personnel. This transition forces companies to start using game engines as a foundation to develop such iVTEs, which also requires a multidisciplinary team. When developing such training environments, challenges on how to present tasks to users arise. The way these tasks are presented can dictate the efficacy of the VR training application. This paper presents three different task presentation methodologies (avatar animation, videos, and instruction manual) and assesses them using 36 participants, divided into those three groups. Usability, sense of presence, satisfaction, cybersickness, and technology acceptance variables were studied and results indicated that only the total number of actions performed had differences between groups where the instruction manual reported the higher number of actions (usability) when compared to the other conditions. Therefore it was concluded that the instruction manual proved to be where users kept losing focus and making more actions. It was also concluded that all conditions had a similar sense of presence, satisfaction, cybersickness, and acceptance scores.

Abstract
Cybersickness refers to the negative symptoms caused by exposure to a Virtual Reality (VR) experience. The literature is consensual that cybersickness is a key factor in an experience, as the non-existence of cybersickness provides an optimal virtual experience. Thus, it is of utmost importance to evaluate cybersickness when assessing VR applications to understand the impact of this factor on the user experience and, ultimately, on the VR application viability. However, there is a lack of Portuguese instruments to evaluate this variable. To tackle this, this aimed to translate and validate the Simulator Sickness Questionnaire (SSQ) to Portuguese so it can be used with the Portuguese population and maintain its psychometric properties. The new instrument was validated using a sample of 603 Portuguese subjects aged between 16 and 79. Based on the observed results, the obtained theoretical model shows that the Portuguese version of the SSQ is valid for properly evaluating cybersickness in VR experiences with Portuguese samples.

Abstract
Virtual reality (VR) for training helps minimize risks and costs by allowing more frequent and varied use of experiential training experiences, leading to active and improved learning. However, creating VR training experiences is costly and time-consuming, requiring software development experts. Additionally, current authoring tools are desktop-oriented, which detaches the process of creating the immersive experience from experiencing it in a situated context. This paper presents the development of an immersive authoring tool designed to create immersive virtual environments that can be used to train operatives. The authoring tool can record and replay animations of each action the user performed that can later be used to instruct other users how the task should be performed. Participants were divided into two groups, and the proposed authoring tool was evaluated using usability, satisfaction, presence and cybersickness. Between groups, Independent T-tests revealed that there were no significant differences between expert and non-expert groups in any of the studied variables. Also, the results showed that the authoring tool had high usability and satisfaction, average presence, and low probability of cybersickness symptoms.

Abstract
The modern manufacturing environment has adjusted to technological improvements. With Virtual Reality applications geared for factory training are becoming increasingly common. The industry is seeking ways to lower downtimes, resource component waste, risk of possible work accidents and decrease expenses, which can be achieved by engaging in new techniques of training professionals. This article evaluates a VR training application developed within the scope of the R&D project, aimed at training personnel in vehicle antenna production lines. We included the following variables: previous experience with VR technology, cybersickness, immersive tendencies, presence, system usability and satisfaction. Both the system usability scores and satisfaction were considered acceptable. We also found positive correlations between several variables, highlighting the possible influence of attention and familiarity with VR technology on the user experience. In contrast, a negative correlation raised questions about participants' expectations regarding VR technology and their resulting experience.

Abstract
We experience the world around us using all our senses, however, multimedia content still relies majorly on audiovisual stimuli. With technology advancements, multisensory stimuli started to be introduced in multimedia experiences. Still, very few contemplate a wide range of different modalities simultaneously, approaching the stimulation one would receive in reality. This paper explores the effects of trimodal multisensory stimuli on the sense of Presence, Perceptual Realism, and Quality of Experience (QoE) during video visualisation. Namely, we study the impact of heat, wind, and smell during video visualization to investigate how each stimulus contributes to the QoE. A correlational analysis was also performed to understand better how the different variables interact. The results indicate that multisensory stimulation improved significantly the sense of presence satisfaction and perceptual realism. Furthermore, smell contributed the most to the QoE, followed by heat and wind. We highlight the use of multisensory stimulation on video visualization over audiovisual only, as it benefits substantially the user experience. © 2023 IEEE.

Abstract
Immersive Virtual Reality (IVR) provides a platform where the real world can be replicated to a point where users can act and react in the virtual world as they would in reality. However, rendering visual stimuli is computationally heavy. Thus, optimizations must be done to take advantage of computational systems by studying our perception of reality. This study investigated parameters related to light rendering (Global Illumination, Ambient Occlusion, Screen Space Reflections (SSR) and Direct Shadows) in real-time in a virtual replica of a real place using IVR. Participants experienced both virtual and real rooms with only one flashlight and changed the quality settings of the considered parameters so that their sense of reality would be the closest to the one they felt when they experienced the real room. Participants were given a budget to drive them to prioritize what parameters, and their level of quality, are the most important for their sense of reality. Results indicated that participants considered Global Illumination the most important factor, closely followed by Direct Shadows. Ambient Occlusion and Reflections (Screen Space Reflections) were the less prioritized parameters. We conclude that in a lighting setting where only dynamic lights are used, Global Illumination and Direct Shadows should be prioritized over SSR Reflections and Ambient Occlusion when computational power is limited.