Exploration Of Virtual Environments Research Articles

PreVR: Variable-Distance Previews for Higher-Order Disocclusion in VR.

The paper introduces PreVR, a method for allowing the user of a VR application to preview a virtual environment (VE) around any number of corners. This way the user can gain line of sight to any part of the VE, no matter how distant or how heavily occluded it is. PreVR relies on a multiperspective visualization that implements a higher-order disocclusion effect with piecewise linear rays that bend multiple times as needed to reach the visualization target. PreVR was evaluated in a user study ($\mathrm{N}=88$) that investigates four points on the VR interface design continuum defined by the maximum disocclusion order $\delta$. In a first control condition (CC0), $\delta=0$, corresponds to conventional VR exploration with no preview capability. In a second control condition (CC1), $\delta=1$, corresponds to the prior art approach of giving the user a preview around the first corner. In a first experimental condition (EC3), $\delta=3$, so PreVR provided up to third-order disocclusion. In a second experimental condition (ECN), $\delta$ was not capped, so PreVR could provide a disocclusion effect of any order, as needed to reach any location in the VE. Participants searched for a stationary target, for a dynamic target moving on a random continuous trajectory, and for a transient dynamic target that appeared at random locations in the maze and disappeared 5s later. The study quantified VE exploration efficiency with four metrics: viewpoint translation, view direction rotation, number of teleportations, and task completion time. Results show that the previews afforded by PreVR bring a significant VE exploration efficiency advantage. ECN outperforms EC3, CC1, and CC0 for all metrics and all tasks, and EC3 frequently outperforms CC1 and CC0.

Examination of fire scene reconstructions using virtual reality to enhance forensic decision-making. A case study in Scotland.

When attending a crime scene, first responders are responsible for identifying areas of potential interest for subsequent forensic examination. This information is shared with the police, forensic practitioners, and legal authorities during an initial meeting of all interested parties, which in Scotland is known as a forensic strategy meeting. Swift documentation is fundamental to allow practitioners to learn about the scene(s) and to plan investigative strategies, traditionally relying on word-of-mouth briefings using digital photographs, videos, diagrams, and verbal reports. We suggest that these early and critical briefings can be augmented positively by implementing an end-to-end methodology for indoor 3D reconstruction and successive visualisation through immersive Virtual Reality (VR). The main objective of this paper is to provide an integrative documentation tool to enhance the decision-making processes in the early stages of the investigation. Taking a fire scene as an example, we illustrate a framework for rapid spatial data acquisition of the scene that leverages structure-from-motion photogrammetry. We developed a VR framework that enables the exploration of virtual environments on a standalone, low-cost immersive head-mounted display. The system was tested in a two-phased inter-agency fire investigation exercise, where practitioners were asked to produce hypotheses suitable for forensic strategy meetings by (1) examining traditional documentation and then (2) using a VR walkthrough of the same premises. The integration of VR increased the practitioners’ scene comprehension, improved hypotheses formulation with fewer caveats, and enabled participants to sketch the scene, in contrast to the orientation challenges encountered using conventional documentation.

Enhancing mathematical education with spatial visualization tools

IntroductionThis article highlights the innovative approach of incorporating spatial visualization tools in mathematics education, specifically focusing on the exploration of virtual environments and 3D printing. By integrating these advanced technologies, educators can enhance the learning experience and facilitate a deeper understanding of mathematical concepts. This research delves into the potential benefits and practical applications of these tools, shedding light on their effectiveness in fostering spatial reasoning skills and promoting active student engagement. The study aims to uncover new avenues for leveraging technology in the mathematics classroom and re-imagining the teaching and learning process.MethodsTo assess the progress in spatial visualization ability, the Revised Purdue Spatial Visualization Test (Revised PSVT: R) was administered as both a pre-test and a post-test to a sample of 255 students divided into control and experimental groups.ResultsThe findings indicate that the control group exhibited no significant development (p = 0.163) and had a minimal effect size of change (g = 0.035), whereas the experimental group demonstrated a substantial improvement in spatial visualization ability (p < 0.05) with a noteworthy medium effect size of change (g = 0.325). Furthermore, an analysis of variance was conducted to compare the mean normalized change in spatial visualization ability between the control and experimental groups. The results, with 95% confidence, establish that the normalized spatial visualization change is significantly higher in the experimental group. Specifically, the experimental group witnessed a 25% increase in spatial visualization skills, while the control group only experienced a 5% increase.DiscussionOur study demonstrates the significance and effectiveness of integrating spatial visualization tools in mathematics education to enhance students’ spatial reasoning skills and mathematics understanding.

Robust Regional Coordination of Inverter-Based Volt/Var Control via Multi-Agent Deep Reinforcement Learning

Inverter-based Volt/Var control (VVC) methods can effectively address issues of voltage deviations and constraint violations, as well as reduce network power losses in active distribution networks. Conventional VVC mainly relies on rule-based, mathematical, or heuristic methods. However, these methods can be inefficient or even infeasible for large-scale systems, especially when operational uncertainties are considered at both spatial and temporal scales. To this end, firstly, this paper formulates a multi-region coordinated VVC optimization problem to simultaneously minimize bus voltage deviations and network power losses. Furthermore, with the problem being formulated as a partially observable Markov Game, a multi-agent deep deterministic policy gradient (MADDPG) algorithm is modified to solve this problem. Each region, which is a sub-network with a control center, is modeled as an agent and learns to optimize inverter reactive power output setpoints through exploration in virtual environment and improved neural network training procedure. Spatial and temporal uncertainties of photovoltaic power generation and loads are modeled by stochastic programming as scenarios in the MADDPG algorithm. This algorithm can address the uncertainties to guarantee solution robustness. Thus, this paper eventually proposes a robust regionally coordinated VVC method, and numerical simulations indicate high computing efficiency and robust optimum.

Automatic global path generation for large-scale 3D scene exploration

Large-scale virtual scene exploration is still a challenging task. The novice users can easily get distracted and disorientated, which results in being lost in space. Assisted camera control technology is the most effective solution for virtual environment exploration problems which requires viewpoint computation and path planning. In this paper, a novel approach for large-scale virtual scene based on viewpoint scoring is proposed. First, the scene was adaptively divided into several meaningful and easily analyzed subregions according to the optimal view distance criterion. Second, a novel viewpoint scoring method based on visual perception and information entropy fusion was developed for optimal viewpoint determination and greedy N-Bestviewpoint selection algorithm was utilized for visual perceptibility calculation. Then evolutionary programming approach for the Traveling Salesman problem was applied for intra-subregion and inter-subregion exploring path optimization. Finally, the Cubic Hermite Curve was introduced to smoothen the inflection point on the exploration path. The experimental results demonstrate that the proposed method can effectively generate an automatic smooth, informative, aesthetic and non-intersecting path, with the characteristics of good exploring comfort, strong immersion and high scene information perception.

Nurse-Physician Communication Team Training in Virtual Reality Versus Live Simulations: Randomized Controlled Trial on Team Communication and Teamwork Attitudes.

BackgroundInterprofessional team training is needed to improve nurse-physician communication skills that are lacking in clinical practice. Using simulations has proven to be an effective learning approach for team training. Yet, it has logistical constraints that call for the exploration of virtual environments in delivering team training.ObjectiveThis study aimed to evaluate a team training program using virtual reality vs conventional live simulations on medical and nursing students’ communication skill performances and teamwork attitudes.MethodsIn June 2018, the authors implemented nurse-physician communication team training using communication tools. A randomized controlled trial study was conducted with 120 undergraduate medical and nursing students who were randomly assigned to undertake team training using virtual reality or live simulations. The participants from both groups were tested on their communication performances through team-based simulation assessments. Their teamwork attitudes were evaluated using interprofessional attitude surveys that were administered before, immediately after, and 2 months after the study interventions.ResultsThe team-based simulation assessment revealed no significant differences in the communication performance posttest scores (P=.29) between the virtual and simulation groups. Both groups reported significant increases in the interprofessional attitudes posttest scores from the baseline scores, with no significant differences found between the groups over the 3 time points.ConclusionsOur study outcomes did not show an inferiority of team training using virtual reality when compared with live simulations, which supports the potential use of virtual reality to substitute conventional simulations for communication team training. Future studies can leverage the use of artificial intelligence technology in virtual reality to replace costly human-controlled facilitators to achieve better scalability and sustainability of team-based training in interprofessional education.Trial RegistrationClinicalTrials.gov NCT04330924; https://clinicaltrials.gov/ct2/show/NCT04330924

CAN IMMERSIVE VIRTUAL REALITY TRAVEL EXPERIENCE REPLACE REAL TRAVEL?

Purpose. The study attempts to define virtual reality in tourism as well as to characterise and present chosen applications created for the purposes of virtual sightseeing. Based on the survey conducted among tourism and recreation students of the Jerzy Kukuczka Academy of Physical Education in Katowice, the study attempts to answer the provocative question: “can virtual tourism replace real-world travel?”, and to analyse participants’ opinions on the topic of virtual trips. Methods. Analysis of scientific studies as well as information and data on the possibility of using immersive virtual reality in human life with particular consideration given to tourism. An overview of applications enabling taking trips through immersive exploration of virtual environments. The survey was conducted among AWF students. Participants expressed their opinions about virtual sightseeing. Findings. Virtual reality is increasingly used in various fields of human life. It is entering the world of tourism, in which it is used to create presentations of hotels and resorts, and to promote towns and tourist facilities. Appropriate software and IT equipment allow to take deliberate, planned and very realistic virtual trips. The authors of the work defined such tourism as all activities carried out by persons who immerse themselves in virtual reality for learning and entertainment purposes in order to experience the illusion of change of their everyday, real surroundings in time and space. Tourism understood in such a way allows us not only to go to almost any place without the necessity of leaving home. It also allows for visiting areas and objects which cannot be explored in real life. It enables a visitor, among others, to travel in space and visit historical sites which no longer exist in their original form, but have been recreated in computer applications. Virtual tourism also allows for exploring fictional locations created by designers of photorealistic graphics as well as valuable and sensitive monuments, and taking trips to places which are dangerous or prohibited. In the conducted survey, it has been concluded that even though tourism and recreation students found experience with virtual reality to be positive, the majority is not convinced that this form of tourism can replace real-world travel. Research and conclusions limitations. There are only a few publications concerning immersive virtual reality travel experience. Access to the software was quite early. Practical implications. Understanding and reorganisation of issues related to immersive virtual reality travel experience. The study may constitute an original introduction and encouragement to carry out qualitative and quantitative research on newly created virtual tourism. Originality. An original concept of understanding virtual tourism was presented. Type of paper. Empirical research and review.

Multiobjective Reinforcement Learning for Cognitive Satellite Communications Using Deep Neural Network Ensembles

Future spacecraft communication subsystems will potentially benefit from software-defined radios controlled by artificial intelligence algorithms. In this paper, we propose a novel radio resource allocation algorithm leveraging multiobjective reinforcement learning and artificial neural network ensembles able to manage available resources and conflicting mission-based goals. The uncertainty in the performance of thousands of possible radio parameter combinations and the dynamic behavior of the radio channel over time producing a continuous multidimensional state–action space requires a fixed-size memory continuous state–action mapping instead of the traditional discrete mapping. In addition, actions need to be decoupled from states in order to allow for online learning, performance monitoring, and resource allocation prediction. The proposed approach leverages the authors’ previous research on constraining decisions predicted to have poor performance through ”virtual environment exploration.” The simulation results show the performance for different communication mission profiles, and accuracy benchmarks are provided for the future research reference. The proposed approach constitutes part of the core cognitive engine proof-of-concept delivered to the NASA John H. Glenn Research Center’s SCaN Testbed radios on-board the International Space Station.

Differences between blind people's cognitive maps after proximity and distant exploration of virtual environments

Visits to simulations of real spaces in virtual reality have been proposed as a means for blind people to gain spatial knowledge regarding the disposition of obstacles within a place before actually visiting it. Within the present study, different configurations of distant and proximity exploration were compared to each other, in order to test whether differences in effectiveness and efficiency lead to changes in exploration behaviour, without a detrimental impact on cognitive-map quality and usefulness. Evidence supports effectiveness improvements due to distant exploration (p-value = 0.0006). The flat-spotlight distant-configuration entails a 53% reduction in discovery time (p-value = 0.0027). A trend is observed entailing a 38% reduction in the duration of the overall exploration stage for a flat spotlight configuration (p-value = 0.067). Wall-detection effectiveness alters exploration duration (p-value = 0.012). Improvements in effectiveness and discovery time are associated with shorter overall exploration time. Duration of exploration after discovery time depends on wall-detection effectiveness. Benefits from a distant exploration configuration are not enough to build better cognitive maps.

Three-Dimensional Skin Deformation as Force Substitution: Wearable Device Design and Performance During Haptic Exploration of Virtual Environments.

Virtual reality systems would benefit from a compelling force sensory substitute when workspace or stability limitations prevent the use of kinesthetic force feedback systems. We present a wearable fingertip haptic device with the ability to make and break contact in addition to rendering both shear and normal skin deformation to the fingerpad. A delta mechanism with novel bias spring and tether actuator relocation method enables the use of high-end motors and encoders, allowing precise device control: 10 Hz bandwidth and 0.255 mm RMS tracking error were achieved during testing. In the first of two experiments, participants determined the orientation of a stiff region in a surrounding compliant virtual surface with an average angular error of 7.6 degree, similar to that found in previous studies using traditional force feedback. In the second experiment, we evaluated participants' ability to interpret differences in friction. The Just Noticeable Difference (JND) of surface friction coefficient discrimination using our skin deformation device was 0.20, corresponding with a reference friction coefficient of 0.5. While higher than that found using kinesthetic feedback, this demonstrates that users can perceive differences in surface friction without world-grounded kinesthetic forces. These experiments show that three DoF skin deformation enables both stiffness and friction discrimination capability in the absence of kinesthetic force feedback.

Defining the cognitive enhancing properties of video games: Steps Towards Standardization and Translation.

Ever since video games were available to the general public, they have intrigued brain researchers for many reasons. There is an enormous amount of diversity in the video game research, ranging from types of video games used, the amount of time spent playing video games, the definition of video gamer versus non-gamer to the results obtained after playing video games. In this paper, our goal is to provide a critical discussion of these issues, along with some steps towards generalization using the discussion of an article published by Clemenson and Stark (2005) as the starting point. The authors used a distinction between 2D versus 3D video games to compare their effects on the learning and memory in humans. The primary hypothesis of the authors is that the exploration of virtual environments while playing video games is a human correlate of environment enrichment. Authors found that video gamers performed better than the non-video gamers, and if non-gamers are trained on playing video gamers, 3D games provide better environment enrichment compared to 2D video games, as indicated by better memory scores. The end goal of standardization in video games is to be able to translate the field so that the results can be used for greater good.

Virtual Environments for People who Are Visually Impaired Integrated into an Orientation and Mobility Program

Introduction The BlindAid, a virtual system developed for orientation and mobility (O&M) training of people who are blind or have low vision, allows interaction with different virtual components (structures and objects) via auditory and haptic feedback. This research examined if and how the BlindAid that was integrated within an O&M training program could be of help when teaching those who are blind or visually impaired to develop O&M skills. Methods Using qualitative and quantitative methods, this research focused on 16 participants during their O&M course, and studied virtual environment exploration and orientation tasks in virtual environments. Results The encouraging results of the current study indicate the potential strengths of the BlindAid system as an O&M training device for visually impaired people. Discussion Follow-up research evaluating transference of knowledge from virtual environments to real spaces could contribute to O&M training for people who are visually impaired. Implications for practitioners BlindAid could play a central role in three potential applications: a training simulator for O&M, a diagnostic tool for O&M specialists to track and observe participants’ spatial behavior, and a technique for advanced exploration of unknown spaces.

Virtual Worlds: In-world Survey Methodological Considerations

Second Life (SL) offers unique opportunities for research and exploration in virtual environments. A review of current research regarding SL has examined the influence of real world social influences in online interactions and what the effects on users may be. This suggests the importance of developing an understanding of the relationship between users' real life (RL) and their SL. Some research has begun to reveal the effectiveness of telecommunication and computer simulation with certain clients in the fields of mental health and human services, yet there is a lack of sufficient research done within the context of virtual worlds. This study illustrates a methodology which can be used for online and in-world survey data collection of participants in SL. Limitations encountered as well as suggestions for refinement are discussed. Implications for human services are discussed including engaging clients using incentives for social participation built into the SL milieu.

Automatic path generation for terrain navigation

Navigation in 3D terrain is considered to be a challenging task and requires virtual camera control skills such as zooming, panning and tilting. Novice users can easily get distracted and disorientated which may result in being lost in space. Solutions for the virtual environment exploration problems are still being researched in order to assist users during their journey inside virtual environments. Among these solutions, assisted camera control techniques require viewpoint computation and path planning. This paper introduces a novel approach to navigate over a 3D terrain using best viewpoints. We exploit the concept of Viewpoint Entropy for best view determination and use Greedy N-Best View Selection for visibility calculations. We integrate road network data to extract regions for detailed visibility analysis in subsections of the terrain. In order to connect the calculated viewpoints, we use an evolutionary programming approach for the Traveling Salesman problem. We present the generated tour using a Google Earth framework.The computed and planned viewpoints in our solution reduce human effort when used as starting points for scene exploration or to generate the representative images of the terrain dataset. The proposed framework can be integrated into 3D game engines or urban visualization systems. This integration gives quickly a glimpse or tour of the environment for novice users without the help of prior planning. Furthermore, terrain visibility used together with road network data and an optimization method for final path construction allows the computed path to be used for large urban area reconnaissance and surveillance tasks with aerial vehicles.

The Avatar as a Methodological Tool for the Embodied Exploration of Virtual Environments

In his article "The Avatar as a Methodological Tool for an Embodied Exploration of Virtual Environments" Kris Pint proposes a theoretical framework for the analysis of environments which cannot be entered physically because they are fictional, inaccessible, or destroyed. As phenomenology has already emphasized, the analysis of space has to take into account the bodily involvement of the researcher. Pint introduces the notion of the avatar to compensate for the impossibility of actually accessing the aforementioned spaces. Borrowed from game design, the avatar allows us to include this bodily aspect in the exploration of virtual environments, without neglecting the specific characteristics of an immersion in a virtual space. The aim is to make the avatar operational as a research tool by combining Roland Barthes's use of fantasy in his theory of reading with a reinterpretation of Gilles Deleuze and Félix Guattari's notions of the conceptual persona and the aesthetic figure. To illustrate this research method, Pint uses a number of avatars related to the fantasy of not-belonging to explore the virtual environments of modernist architecture, literature, and painting.

Interactive Navigation and Exploration of Virtual Environments on Handheld Devices

Arbitrarily 3D scenes pose difficult challenges to real-time visualization, navigation and exploration on mobile devices. We have developed a framework for supporting interactive navigation and exploration of mobile virtual environments. Our framework can be used to load dynamically virtual environments from a remote PC server, navigate through them, find an optimal and collision-free path from one place to another, and obtain additional information on the objects of interest by directly pointing to their representation in the virtual world. As a proof of concept of the framework as well as to illustrate its use and main functionalities, we have run tests with a virtual world containing more than one hundred thousand triangles. A walkthrough of this world shows how the framework allocates resources (memory and processing time) to execute the tasks of rendering, geometric transformations, collision detection, and scenes loading, and how its performance is affected under different navigation scenarios.

On the effect of free vs. restricted interaction during the exploration of virtual environments

Exploration of a Virtual Environment (VE) might vary as well in applied technology as in the conceptual design. A conceptual difference of exploring style and navigation type relates to the degree of freedom a user possesses. It ranges from completely unrestricted to completely restricted navigation. To assess the impact of different exploration styles, an experiment was carried out. Four different styles were compared in a large-scale VE. The navigation of the participants was either free or restricted in various levels concerning motion and viewing direction. During the exploration, the participants memorized the location of flags, which represented special events at these locations. The participant's task was to memorize position and color of the flags. Subsequently, they marked the positions and colors of the flags in a map of the scene. The performance in this task was captured, as well as data about their amount of experienced simulator sickness and subjective workload. Additionally, balancing tests were administered to investigate in an objective measurement of simulator sickness. Each condition showed the same achievement in the memorizing task and the subjective workload. Furthermore, the measured high variance in simulator sickness symptoms overrode other effects. In the balancing tests a basic influence of exposure with VE was found. However, subsequent interviews with the participants showed that the personal impression of the efficiency of exploration method was highly individual. By finding and matching exploration methods to individual persons, benefit by using Virtual environments could be enhanced.

The eye caught in the Net: A study on attention and motivation in virtual environment exploration

In virtual environment exploration, the user's gaze must be attracted by important features and information, but capturing user attention is not a straightforward task for designers. The dynamics of attention have been generally thought to be affected either by factors in the external environment, or by internal, motivational factors. The interaction between these two types of factor guides the user's exploration and hence should be taken into consideration in web design. Two experiments were carried out to explore the role of internal and external factors in controlling attention processes in a website task. The results suggested that the dynamics of attention are strongly influenced by internal motivation in this context. It was concluded that individual motivation plays a crucial and often predominant role in controlling attention when participants are engaged in activities using the internet.

Touch-enabled haptic modeling of deformable multi-resolution surfaces

Currently, interactive data exploration in virtual environments is mainly focused on vision-based and non-contact sensory channels such as visual/auditory displays. The lack of tactile sensation in virtual environments removes an important source of information to be delivered to the users. In this paper, we propose the touch-enabled haptic modeling of deformable multi-resolution surfaces in real time. The 6-DOF haptic manipulation is based on a dynamic model of Loop surfaces, where the dynamic parameters are computed easily without subdividing the control mesh recursively. A local deforming scheme is developed to approximate the solution of the dynamics equations, thus the order of the linear equations is reduced greatly. During each of the haptic interaction loop, the contact point is traced and reflected to the rendering of updated graphics and haptics. The sense of touch against the deforming surface is calculated according to the surface properties and the damping-spring force profile. Our haptic system supports the dynamic modeling of deformable Loop surfaces intuitively through the touch-enabled interactive manipulation.

Acquiring Spatial Knowledge While Traveling Simple and Complex Paths with Immersive and Nonimmersive Interfaces

Exploration of virtual environments may be accomplished with different interface metaphors. Previous research suggests that vestibular and proprioceptive information provided by immersive interfaces facilitates spatial orientation on simple path-integration tasks. We examine whether these interface variables impact performance across paths of variable complexity. Our immersive interface provided all users the ability to conduct the search component of our task more efficiently. Our results, however, show that the immersive interface was no more effective than our nonimmersive one for maintaining orientation. In fact, the immersive interface had a negative impact on performance (absolute error) for individuals who had extensive experience with playing video games. When measured in terms of consistency of response, our results suggest that having extensive game-play experience will negatively impact orientation performance with both interfaces. We speculate that this is due to the conflicting nature of the skills that avid game players acquire in game-play versus those required to perform in our task.