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Visual Realism Enhances Realistic Response in an Immersive Virtual Environment - Part 2

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Abstract

Does realistic lighting in an immersive virtual reality application enhance presence, where participants feel that they are in the scene and behave correspondingly? Our previous study indicated that presence is more likely with real-time ray tracing compared with ray casting, but we could not separate the effects of overall quality of illumination from the dynamic effects of real-time shadows and reflections. Here we describe an experiment where 20 people experienced a scene rendered with global or local illumination. However, in both conditions there were dynamically changing shadows and reflections. We found that the quality of illumination did not impact presence, so that the earlier result must have been due to dynamic shadows and reflections. However, global illumination resulted in greater plausibility - participants were more likely to respond as if the virtual events were real. We conclude that global illumination does impact the responses of participants and is worth the effort.
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Digital Object Indentifier 10.1109/MCG.2011.69 0272-1716/$26.00 2011 IEEE
This article has been accepted for publication in IEEE Computer Graphics and Applications but has not yet been fully edited.
Some content may change prior to final publication.
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Digital Object Indentifier 10.1109/MCG.2011.69 0272-1716/$26.00 2011 IEEE
This article has been accepted for publication in IEEE Computer Graphics and Applications but has not yet been fully edited.
Some content may change prior to final publication.
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Digital Object Indentifier 10.1109/MCG.2011.69 0272-1716/$26.00 2011 IEEE
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Digital Object Indentifier 10.1109/MCG.2011.69 0272-1716/$26.00 2011 IEEE
This article has been accepted for publication in IEEE Computer Graphics and Applications but has not yet been fully edited.
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Digital Object Indentifier 10.1109/MCG.2011.69 0272-1716/$26.00 2011 IEEE
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Digital Object Indentifier 10.1109/MCG.2011.69 0272-1716/$26.00 2011 IEEE
This article has been accepted for publication in IEEE Computer Graphics and Applications but has not yet been fully edited.
Some content may change prior to final publication.
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Digital Object Indentifier 10.1109/MCG.2011.69 0272-1716/$26.00 2011 IEEE
This article has been accepted for publication in IEEE Computer Graphics and Applications but has not yet been fully edited.
Some content may change prior to final publication.
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Digital Object Indentifier 10.1109/MCG.2011.69 0272-1716/$26.00 2011 IEEE
This article has been accepted for publication in IEEE Computer Graphics and Applications but has not yet been fully edited.
Some content may change prior to final publication.
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Digital Object Indentifier 10.1109/MCG.2011.69 0272-1716/$26.00 2011 IEEE
This article has been accepted for publication in IEEE Computer Graphics and Applications but has not yet been fully edited.
Some content may change prior to final publication.
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Digital Object Indentifier 10.1109/MCG.2011.69 0272-1716/$26.00 2011 IEEE
This article has been accepted for publication in IEEE Computer Graphics and Applications but has not yet been fully edited.
Some content may change prior to final publication.
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Digital Object Indentifier 10.1109/MCG.2011.69 0272-1716/$26.00 2011 IEEE
This article has been accepted for publication in IEEE Computer Graphics and Applications but has not yet been fully edited.
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Digital Object Indentifier 10.1109/MCG.2011.69 0272-1716/$26.00 2011 IEEE
This article has been accepted for publication in IEEE Computer Graphics and Applications but has not yet been fully edited.
Some content may change prior to final publication.
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Digital Object Indentifier 10.1109/MCG.2011.69 0272-1716/$26.00 2011 IEEE
This article has been accepted for publication in IEEE Computer Graphics and Applications but has not yet been fully edited.
Some content may change prior to final publication.
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Digital Object Indentifier 10.1109/MCG.2011.69 0272-1716/$26.00 2011 IEEE
This article has been accepted for publication in IEEE Computer Graphics and Applications but has not yet been fully edited.
Some content may change prior to final publication.
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Digital Object Indentifier 10.1109/MCG.2011.69 0272-1716/$26.00 2011 IEEE
This article has been accepted for publication in IEEE Computer Graphics and Applications but has not yet been fully edited.
Some content may change prior to final publication.
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Digital Object Indentifier 10.1109/MCG.2011.69 0272-1716/$26.00 2011 IEEE
This article has been accepted for publication in IEEE Computer Graphics and Applications but has not yet been fully edited.
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Digital Object Indentifier 10.1109/MCG.2011.69 0272-1716/$26.00 2011 IEEE
This article has been accepted for publication in IEEE Computer Graphics and Applications but has not yet been fully edited.
Some content may change prior to final publication.
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Digital Object Indentifier 10.1109/MCG.2011.69 0272-1716/$26.00 2011 IEEE
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Digital Object Indentifier 10.1109/MCG.2011.69 0272-1716/$26.00 2011 IEEE
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Some content may change prior to final publication.
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Digital Object Indentifier 10.1109/MCG.2011.69 0272-1716/$26.00 2011 IEEE
This article has been accepted for publication in IEEE Computer Graphics and Applications but has not yet been fully edited.
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Digital Object Indentifier 10.1109/MCG.2011.69 0272-1716/$26.00 2011 IEEE
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... To confirm whether this increase in presence was caused by the more realistic illumination of the scene, the authors performed a second study (N = 21) where they again compared the two lighting conditions. However, this time both had dynamic effects [35]. The VE and visualization system were different in this experiment. ...
... The literature seems to suggest that both HR and HRV are capable of identifying users' sense of presence when the VE is designed to cause a strong reaction in the user, as is the case of a stressful situation [8], [31], [34] or the case of inducing presence breaks [32]. Furthermore, the literature seems to suggest that although HRV cannot differentiate participants' responses to similar VEs [34], [35], they can detect differences in user response in different temporal segments [28], [32], [33]. ...
Article
The use of Virtual Reality (VR) technology to train professionals has increased over the years due to its advantages over traditional training. This paper presents a study comparing the effectiveness of a Virtual Environment (VE) and a Real Environment (RE) designed to train firefighters. To measure the effectiveness of the environments, a new method based on participants Heart Rate Variability (HRV) was used. This method was complemented with self-reports, in the form of questionnaires, of fatigue, stress, sense of presence, and cybersickness. An additional questionnaire was used to measure and compare knowledge transfer enabled by the environments. The results from HRV analysis indicated that participants were under physiological stress in both environments, albeit with less intensity on the VE. Regarding reported fatigue and stress, the results showed that none of the environments increased such variables. The results of knowledge transfer showed that the VE obtained a significant increase while the RE obtained a positive but non-significant increase (median values, VE: before 4 after 7, p = .003; RE: before 4 after 5, p =.375). Lastly, the results of presence and cybersickness suggested that participants experienced high overall presence and no cybersickness. Considering all results, the authors conclude that the VE provided effective training but that its effectiveness was lower than that of the RE.
... Visual richness might confound our results. There are mixed results on whether visual richness does 79,123,219,247 or does not 54,128,138,143,255 modulate presence. In our study, participants received more visual information when they saw a virtual hand compared to no hand. ...
... have a virtual body.86,87,156,220,252 Our findings support the hypothesis that the comparison of actual and predicted sensations modulates presence.172,205,219 Visual feedback generated predictions about haptic feedback. ...
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Human-computer interfaces have the potential to support mental health practitioners in alleviating mental distress. Adaption of this technology in practice is, however, slow. We provide means to extend the design space of human-computer interfaces for mitigating mental distress. To this end, we suggest three complementary approaches: using presentation technology, using virtual environments, and using communication technology to facilitate social interaction. We provide new evidence that elementary aspects of presentation technology affect the emotional processing of virtual stimuli, that perception of our environment affects the way we assess our environment, and that communication technologies affect social bonding between users. By showing how interfaces modify emotional reactions and facilitate social interaction, we provide converging evidence that human-computer interfaces can help alleviate mental distress. These findings may advance the goal of adapting technological means to the requirements of mental health practitioners.
... Participants on entering the scene were in a street by a concert hall building, among a crowd of virtual people. The rendering and some interactive aspects of the scene were determined by four factors, and for each we cite previous work where this factor or similar has been studied with respect to presence: (i) the navigation method (walking-in-place (WiP)) where participants mimicked real walking but stayed physically in the same spot, or a point-and-click method [39]; (ii) body representation-whether participants had a full first-person perspective virtual body or just saw virtual hands [27]; (iii) social feedback-whether other crowd members would acknowledge them or not [32]; and (iv) rendering type-whether the environment was rendered more realistically or more cartoon-like [40]. Figure 1 shows the scenario, and it is also shown in the electronic supplementary material, video S1. ...
... The illusion of body ownership that can result from having a virtual body has been shown to have a profound influence on various aspects of participant responses, even including the response to pain [54]. Realistic rendering is more likely to result in greater levels of Psi [27,40]. Social feedback is critical in the maintenance of Psi [55]. ...
Article
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Virtual reality applications depend on multiple factors, for example, quality of rendering, responsiveness, and interfaces. In order to evaluate the relative contributions of different factors to quality of experience, post-exposure questionnaires are typically used. Questionnaires are problematic as the questions can frame how participants think about their experience and cannot easily take account of non-additivity among the various factors. Traditional experimental design can incorporate non-additivity but with a large factorial design table beyond two factors. Here, we extend a previous method by introducing a reinforcement learning (RL) agent that proposes possible changes to factor levels during the exposure and requires the participant to either accept these or not. Eventually, the RL converges on a policy where no further proposed changes are accepted. An experiment was carried out with 20 participants where four binary factors were considered. A consistent configuration of factors emerged where participants preferred to use a teleportation technique for navigation (compared to walking-in-place), a full-body representation (rather than hands only), the responsiveness of virtual human characters (compared to being ignored) and realistic compared to cartoon rendering. We propose this new method to evaluate participant choices and discuss various extensions.
... Over the years, a multitude of studies have been conducted regarding various aspects and their effect on presence in VR. Some examples include locomotion techniques [49,51], visual fidelity [43,62,65], passive and active haptic feedback [25,29], and audio [2]. The role of proprioception and virtual body for presence in VR is well-known [38,42]. ...
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We propose augmenting immersive telepresence by adding a virtual body, representing the user's own arm motions, as realized through a head-mounted display and a 360-degree camera. Previous research has shown the effectiveness of having a virtual body in simulated environments; however, research on whether seeing one's own virtual arms increases presence or preference for the user in an immersive telepresence setup is limited. We conducted a study where a host introduced a research lab while participants wore a head-mounted display which allowed them to be telepresent at the host's physical location via a 360-degree camera, either with or without a virtual body. We first conducted a pilot study of 20 participants, followed by a pre-registered 62 participant confirmatory study. Whereas the pilot study showed greater presence and preference when the virtual body was present, the confirmatory study failed to replicate these results, with only behavioral measures suggesting an increase in presence. After analyzing the qualitative data and modeling interactions, we suspect that the quality and style of the virtual arms, and the contrast between animation and video, led to individual differences in reactions to the virtual body which subsequently moderated feelings of presence.
... Over the years, a multitude of studies have been conducted regarding various aspects and their effect on presence in VR. Some examples include locomotion techniques [49,51], visual fidelity [43,62,65], passive and active haptic feedback [25,29], and audio [2]. The role of proprioception and virtual body for presence in VR is well-known [38,42]. ...
Preprint
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We propose augmenting immersive telepresence by adding a virtual body, representing the user's own arm motions, as realized through a head-mounted display and a 360-degree camera. Previous research has shown the effectiveness of having a virtual body in simulated environments; however, research on whether seeing one's own virtual arms increases presence or preference for the user in an immersive telepresence setup is limited. We conducted a study where a host introduced a research lab while participants wore a head-mounted display which allowed them to be telepresent at the host's physical location via a 360-degree camera, either with or without a virtual body. We first conducted a pilot study of 20 participants, followed by a pre-registered 62 participant confirmatory study. Whereas the pilot study showed greater presence and preference when the virtual body was present, the confirmatory study failed to replicate these results, with only behavioral measures suggesting an increase in presence. After analyzing the qualitative data and modeling interactions, we suspect that the quality and style of the virtual arms, and the contrast between animation and video, led to individual differences in reactions to the virtual body which subsequently moderated feelings of presence.
... Presence (the subjective feeling of being in the virtual environment [24]) is often found in realism related studies [18], [25]- [27], where higher realism results in a higher sense of presence. However, as D. Bowman & R. P. McMahan [27] state, this is not always the case, as in specific fields such as the oil and gas industry, a higher level of realism is necessary to correctly visualise complex 3D models, whereas the sense of presence is not needed. ...
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Proper evaluation of realism in immersive virtual experiences is crucial to ensure optimisation of resources. This way, we can take better decisions while designing realistic immersive experiences, prioritising factors that have a higher impact on the perceived realism of the virtual experience. This systematic review aims to provide readers with an overview of methodologies used throughout the literature to evaluate realism in immersive virtual, augmented and mixed reality. A total of 79 from 1300 gathered articles met the eligibility criteria and were analysed. Results have shown that virtual reality is by far the platform where realism studies were performed. Head-mounted displays are by far the preferred equipment for such studies. Visual realism is the most researched, followed by audiovisual. The majority of methodologies consisted of subjective, as well as a combination of objective and subjective measures. The most used evaluation instrument is questionnaires where many of which are custom and non-validated. Presence questionnaires are the most used ones and are often used to evaluate the presence, perceived realism and involvement. Cybersickness evaluation is consistently assessed by one self-report questionnaire.
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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 analysed papers that compared different levels of realism and evaluated their impact on user experience. Exploratorily, we also synthesised the realism terms used by authors. From 1300 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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Human factors studies are becoming more and more crucial in the automotive sector due to the need to evaluate the driver.s reactions to the increasingly sophisticated driving-assistant technologies. Driving simulators allow performing this kind of study in a controlled and safe environment. However, the driving simulation.s Level of Detail (LOD) can affect the users. perception of driving scenarios and make an experimental campaign.s outcomes unreliable. This paper proposes a study investigating possible correlations between driver.s behaviors and emotions, and simulated driving scenarios. Four scenarios replicating the same real area were built with four LODs from LOD0 (only the road is drawn) to LOD3 (all buildings with real textures for facades and roofs are inserted together with items visible from the road). 32 participants drove in all the four scenarios on a fixed-base driving simulator; their performance relating to the vehicle control (i.e., speed, trajectory, brake and gas pedal use, and steering wheel), their physiological data (electrodermal activity, and eye movements), their subjective perceptions, opinions and emotional state were measured. The results showed that drivers. behavior changes in a very complex way. Geometrical features of the route and environmental elements constrain much more driving behavior than LOD does Emotions are not affected by LODs. Generally, different signals showed different correlations with the LOD level, suggesting that future studies should consider their measures while modeling the virtual scenario. It is hypothesized that scenario realism is more relevant during leisurely environmental interaction, whilst simulator fidelity is crucial in task-driven interactions.
Conference Paper
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Shoulder surfing is an omnipresent risk for smartphone users. However, investigating these attacks in the wild is difficult because of either privacy concerns, lack of consent, or the fact that asking for consent would influence people’s behavior (e.g., they could try to avoid looking at smartphones). Thus, we propose utilizing 360-degree videos in Virtual Reality (VR), recorded in staged real-life situations on public transport. Despite differences between perceiving videos in VR and experiencing real-world situations, we believe this approach to allow novel insights on observers’ tendency to shoulder surf another person’s phone authentication and interaction to be gained. By conducting a study (N=16), we demonstrate that a better understanding of shoulder surfers’ behavior can be obtained by analyzing gaze data during video watching and comparing it to post-hoc interview responses. On average, participants looked at the phone for about 11% of the time it was visible and could remember half of the applications used.
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A new definition of immersion with respect to virtual environment (VE) systems has been proposed in earlier work, based on the concept of simulation. One system (A) is said to be more immersive than another (B) if A can be used to simulate an application as if it were running on B. Here we show how this concept can be used as the basis for a psychophysics of presence in VEs, the sensation of being in the place depicted by the virtual environment displays (Place Illusion, PI), and also the illusion that events occurring in the virtual environment are real (Plausibility Illusion, Psi). The new methodology involves matching experiments akin to those in color science. Twenty participants first experienced PI or Psi in the initial highest level immersive system, and then in 5 different trials chose transitions from lower to higher order systems and declared a match whenever they felt the same level of PI or Psi as they had in the initial system. In each transition they could change the type of illumination model used, or the field-of-view, or the display type (powerwall or HMD) or the extent of self-representation by an avatar. The results showed that the 10 participants instructed to choose transitions to attain a level of PI corresponding to that in the initial system tended to first choose a wide field-of-view and head-mounted display, and then ensure that they had a virtual body that moved as they did. The other 10 in the Psi group concentrated far more on achieving a higher level of illumination realism, although having a virtual body representation was important for both groups. This methodology is offered as a way forward in the evaluation of the responses of people to immersive virtual environments, a unified theory and methodology for psychophysical measurement.
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This paper describes an experiment to assess the anxiety responses of people giving 5 min. presentations to virtual audiences consisting of eight male avatars. There were three different types of audience behavior: an emotionally neutral audience that remained static throughout the talk, a positive audience that exhibited friendly and appreciative behavior towards the speaker, and a negative audience that exhibited hostile and bored expressions throughout the talk. A second factor was immersion: half of the forty subjects experienced the virtual seminar room through a head-tracked, head-mounted display and the remainder on a desktop system. Responses were measured using the standard Personal Report of Confidence as a Public Speaker (PRCS), which was elicited prior to the experiment and after each talk. Several other standard psychological measures such as SCL-90-R (for screening for psychological disorder), the SAD, and the FNE were also measured prior to the experiment. Other response variables included subjectively assessed somaticization and a subject self-rating scale on performance during the talk. The subjects gave the talk twice each to a different audience, but in the analysis only the results of the first talk are presented, thus making this a between-groups design. The results show that post-talk PRCS is significantly and positively correlated to PRCS measured prior to the experiment in the case only of the positive and static audiences. For the negative audience, prior PRCS was not a predictor of post-PRCS, which was higher than for the other two audiences and constant. The negative audience clearly provoked an anxiety response irrespective of the normal level of public speaking confidence of the subject. The somatic response also showed a higher level of anxiety for the negative audience than for the other two, but self-rating was generally higher only for the static audience, each of these results taking into account prior PRCS.
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This paper describes a new measure for presence in immersive virtual environments (VEs) that is based on data that can be unobtrusively obtained during the course of a VE experience. At different times during an experience, a participant will occasionally switch between interpreting the totality of sensory inputs as forming the VE or the real world. The number of transitions from virtual to real is counted, and, using some simplifying assumptions, a probabilistic Markov chain model can be constructed to model these transitions. This model can be used to estimate the equilibrium probability of being “present” in the VE. This technique was applied in the context of an experiment to assess the relationship between presence and body movement in an immersive VE. The movement was that required by subjects to reach out and touch successive pieces on a three-dimensional chess board. The experiment included twenty subjects, ten of whom had to reach out to touch the chess pieces (the active group) and ten of whom only had to click a handheld mouse button (the control group). The results revealed a significant positive association in the active group between body movement and presence. The results lend support to interaction paradigms that are based on maximizing the match between sensory data and proprioception.
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This paper reviews experimental methods for the study of the responses of people to violence in digital media, and in particular considers the issues of internal validity and ecological validity or generalisability of results to events in the real world. Experimental methods typically involve a significant level of abstraction from reality, with participants required to carry out tasks that are far removed from violence in real life, and hence their ecological validity is questionable. On the other hand studies based on field data, while having ecological validity, cannot control multiple confounding variables that may have an impact on observed results, so that their internal validity is questionable. It is argued that immersive virtual reality may provide a unification of these two approaches. Since people tend to respond realistically to situations and events that occur in virtual reality, and since virtual reality simulations can be completely controlled for experimental purposes, studies of responses to violence within virtual reality are likely to have both ecological and internal validity. This depends on a property that we call 'plausibility' - including the fidelity of the depicted situation with prior knowledge and expectations. We illustrate this with data from a previously published experiment, a virtual reprise of Stanley Milgram's 1960s obedience experiment, and also with pilot data from a new study being developed that looks at bystander responses to violent incidents.
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In this paper, I address the question as to why participants tend to respond realistically to situations and events portrayed within an immersive virtual reality system. The idea is put forward, based on the experience of a large number of experimental studies, that there are two orthogonal components that contribute to this realistic response. The first is 'being there', often called 'presence', the qualia of having a sensation of being in a real place. We call this place illusion (PI). Second, plausibility illusion (Psi) refers to the illusion that the scenario being depicted is actually occurring. In the case of both PI and Psi the participant knows for sure that they are not 'there' and that the events are not occurring. PI is constrained by the sensorimotor contingencies afforded by the virtual reality system. Psi is determined by the extent to which the system can produce events that directly relate to the participant, the overall credibility of the scenario being depicted in comparison with expectations. We argue that when both PI and Psi occur, participants will respond realistically to the virtual reality.
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