Abstract
Head-mounted displays enable a user to view a complete environment as if he/she was there; providing an immersive experience. However, the lighting in a full environment can vary significantly. Panoramic images captured with conventional, Low Dynamic Range (LDR), imaging of scenes with a large range of lighting conditions, can include areas of under- or over-exposed pixels. High Dynamic Range (HDR) imaging, on the other hand, is able to capture the full range of detail in a scene. However, HMDs are not currently HDR and thus the HDR panorama needs to be tone mapped before it can be displayed on the LDR HMD. While a large number of tone mapping operators have been proposed in the last 25 years, these were not designed for panoramic images, or for use with HMDs. This paper undertakes a two part subjective study to investigate which of the current, state-of-the-art tone mappers is most suitable for use with HMDs.

Abstract

Abstract
The current technologic proliferation has originated new paradigms concerning the production and consumption of multimedia content. This paper proposes a multisensory 360 video editor that allows producers to edit such contents with high levels of customization. This authoring tool allows the edition and visualization of 360 video with the novelty of allowing to complement the 360 video with multiple stimuli such as audio, haptics, and olfactory. In addition to this multisensory feature, the authoring tool allows customizing individually each of the stimuli to provide an optimal multisensory user experience. A usability evaluation has revealed the pertinence of the editor, where it was verified an effectiveness rate of 100%, only one help request out of 10 participants, and positive efficiency. Satisfaction-wise, results equally revealed high level of satisfaction as the average score was 8.3 out of 10. © Springer International Publishing AG, part of Springer Nature 2018.

Abstract
Navigation through immersive virtual environments is a key concept for virtual reality as it allows users to explore those environments. Therefore, it is important to understand virtual reality navigation interfaces and their impact on the users' experience. This paper presents an objective performance evaluation of two types of navigation: natural (real walking and walk-in-place) vs. unnatural (gamepad). Steering Law was the objective performance metric chosen since it captures the relationship between the time to travel a path and the difficulty of that path. In addition to performance, subjective metrics were also considered, namely the feeling of presence, cybersickness and user satisfaction. The experiments consisted of having participants complete a series of paths with different indexes of difficulty and the time that a participant took to walk each path was measured. Overall results show that the navigation through real walking yielded better results when it comes to performance, cybersickness, and user satisfaction than the walk-in-place and gamepad navigation interfaces.

Abstract
New virtual reality technologies allow the user to gain a greater sense of presence in virtual environments. One of the areas where these technologies can have a major impact is the area of games that allow users to explore these environments and interact with them by receiving feedback from their actions in real time. The present study aimed to evaluate if the use of physiological signals to update the virtual environment in real-time could be used to increase the feeling of presence. To perform this study, an experimental study was designed based on a game that allowed the use of physiological data to calculate the participant's arousal in real-time and, based on that, modify certain elements of the virtual environment where the participants were asked to fulfill a task. With the analysis of the data obtained, it was possible to verify that the use of biofeedback did not reveal statistically significant differences for the variables tested, however, it can be concluded that the use of biofeedback improves some subscales of presence, being the users with more experience in games and more computer knowledge susceptible to such changes.

Abstract
The use of technology in cultural heritage sites, like virtual reconstructions, has become a common solution to improve the communication between these spaces and their visitors. The amount of virtual information is flexible and it depends on what it is intended to transmit. Since humans perceive the world with different senses and in real-time, it is being noticeable the emergence of several applications using multisensory elements. Despite the implementations and related evaluations being scarce, the more recent studies depicts that this technology prize and enhance users' experiences when more stimuli are exploited. This paper presents a survey related to the recent studies made in this context, in order to identify the actual scope of multisensory experiences in cultural heritage sites.