Computational memory architectures for autobiographic agents interacting in a complex virtual environment: a working model

Through technological advancements, the use of virtual environments (VE) in education and training has increased. One challenge that users face is the task of navigation in virtual environments. This research investigates navigation within a virtual environment and how users utilize different navigational tools. Navigational tools are categorized as either active or passive, based on the type of information that they present. The goal of this study was to determine if there are differences in the ways that users use passive and active navigational tools. This study was conducted by collecting eye fixations and fixation durations while participants used a navigation tool in completing a task in a VE. Results revealed no significant difference between percentage of fixations and fixation durations and future research should investigate the comparison of active and passive navigational tools in more complex virtual environments.

This study aimed to explore how a three-dimensional (3D) map affects the acquisition of survey knowledge in complex virtual environments (VEs). Subject navigated in virtual and real subway stations, where the virtual station was augmented with either a 3D floor map, a 3D building map, or neither. After subject's navigation in the station, they made the judgment of spatial relative directions between objects. The analyses of response time showed that participants responded faster when they were assisted by the 3D floor or building map than without a map aid in virtual stations. There was no significant difference between survey knowledge acquired in the virtual station augmented with the 3D floor or building map and in the real station. Participants with the 3D floor map performed best in spatial judgments. Implications of these findings to a 3D map design were discussed.

Standard approaches to cognitive remediation can suffer from limited skill transferability to patients’ life. Complex virtual environments (VEs) enable us to create ecologically valid remediation scenarios while preserving laboratory conditions. Nevertheless, the feasibility and efficacy of these programs in psychiatric patients are still unknown. Our aim was to compare the feasibility and efficacy of a novel rehabilitation program, designed in complex VEs, with standard paper–pencil treatment in patients with schizophrenia and major depressive disorder. We recruited 35 participants to complete a VE rehabilitation program and standard treatment in a crossover pilot study. Twenty-eight participants completed at least one program, 22 were diagnosed with schizophrenia and 6 with major depressive disorder. Participant’s performance in the representative VE training task significantly improved in terms of maximum achieved difficulty (p ≤ 0.001), speed (p < 0.001) and efficacy (p ≤ 0.001) but not in item performance measure. Neither the standard treatment nor the VE program led to improvement in standardized cognitive measures. Participants perceived both programs as enjoyable and beneficial. The refusal rate was higher in the VE program (8.6%) than in the standard treatment (0%). But in general, the VE program was well-accepted by the psychiatric patients and it required minimal involvement of the clinician due to automatic difficulty level adjustment and performance recording. However, the VE program did not prove to be effective in improving cognitive performance in the standardized measures.

In an empirical evaluation, we examined participants' visual attention allocation to a dynamic wayfinding map in a complex simulation meant to educate medical practitioners in a hand hygiene protocol. Complex virtual environments (VEs) are novel types of virtual worlds that embody large spaces, interactive virtual humans, static and dynamic virtual entities, and intricate tasks that simulate real-world settings. Previous investigations of wayfinding aids have focused on the evaluation of spatial orientation, knowledge acquisition, and usage. We employed an eye tracker and created visualization tools to quantitatively and qualitatively analyze participants' visual attention to the wayfinding aid in our simulation. Results suggest that the proportion of time of gaze, total gaze count, and gaze transitions between various elements of the VE are altered with the use of the wayfinding aid. Participants also tend to employ innovative visual strategies in order to efficiently plan routes and accomplish tasks in the VE.

Facial modeling and animation are important research topics in computer graphics. During the last 20 years, a lot of research has been done in these areas, but it still remains a challenging task. The impact of previous and ongoing research has been felt in many applications, like games, Web-based 3D animations, 3D animation movies, etc. Two directions are investigated: precalculating animation with very realistic results for animated films and real-time animation for interactive applications. Correspondingly, the animation techniques vary from key-frame animations, where animators set each frame, to algorithmic parameterized mesh deformation. Many of the proposed deformation models use a parameterization scheme, which helps control the animation. Computer graphics have evolved to a relatively mature state. In parallel to the evolution of 3D graphics technologies, user and application requirements have also dramatically increased from simple virtual worlds to highly complex, interactive, and detailed virtual environments. Additionally, the targeted display platforms have widely broadened from dedicated graphics workstations or clusters of machines to standard desktop PCs, laptops, and mobile devices such as personal digital assistants (PDAs) or even mobile phones. Facial animation can be one illustration of such closely related evolutions of graphics techniques and corresponding applications and user’s requirements. Actually, despite much research and work on modeling, animation, and rendering techniques, it is still an important challenge to animate a highly realistic face with simulated hair and cloth, to display hundred of thousands of real-time animated humans on a standard computer, and it is still not possible to render animated characters on most mobile devices. The focus of this chapter is to present dynamically adaptive real-time facial animation techniques. We discuss methods to automatically and dynamically control the processing and memory loads together with the visual realism of rendered motions for real-time facial animation. Such approaches would theoretically allow us to free additional resources for hair or cloth animation; for instance, it should also achieve real-time performance for facial animation on multiplatform and on lightweight devices, as well as enable improvements to virtual environments with the addition of more and more facially animated humans in a single scene.

Location and behavior decision-making of intelligent actor in complex virtual environment is a difficult uncertain problem, aiming to the problem in the process of picking manipulator location and behavior decision-making in complex environment, the virtual intelligent actor's definition and its behaviors modeling based on exploratory analysis was firstly proposed in the article. A sextuple function for describing the actor's behaviors, behavioral events, thinking manner, and the behavioral function and communication mechanism were also discussed in the text. Finally, taking the picking manipulator's behaviors as instance, the mechanical character parameter was optimizes with the method of exploratory analysis, and the behaviors of targets' acquisition and orientation of virtual actors were simulated.

The 90s and 00s saw great hopes that virtual reality was poised to sweep health care and change everything. But it didn't. Though researchers could immerse themselves in more complex virtual environments, the chasm between that digital experience and the complexity of real life - using a VR system in an hospital without a dedicated technician was a real challenge - just was too great. Now the situation is changing quickly. The rise of Oculus Rift and the shift of virtual reality from PC to mobile phones thanks to both the Oculus designed Gear VR headsets for Samsung phones and the Google Cardboard project are going to transform health care tools and experiences.

Vehicle testing is a key factor in motorsport field, always oriented towards maximizing performance. In last decades, testing procedures have evolved, going from classic outdoor tests to indoor test benches capable of stressing the vehicle in different ways, up to complex virtual simulation environments. In this scenario, this work presents a virtual 7-post rig, based on a seven degree of freedom vehicle model developed with a Lagrangian approach, able to reproduce the vertical behaviour of sprung and unsprung masses. This model could represent a valid alternative to the real test bench, allowing a significant reduction in the testing phase time and costs. The model performance has been assessed by means of a comparison with a much more complex simulation environment and from the comparison of the results it is clear that the developed model can be actually used for the evaluation of the optimal conditions of stiffness and damping of the suspension.KeywordsVehicle model7-Post RigSuspensions optimizationLagrangian method

VIRTUAL REALITY IN PSYCHOSIS: EXPERIMENTS WITH SOCIAL RISK ENVIRONMENTS

Recent years have seen growing interest in using virtual acoustic scenes in laboratory environments to emulate real-life complex listening environments. Questions remain, however, regarding the degree to which virtual environments reflect typical complex listening environments in daily life. In this study, participants with and without hearing loss completed speech perception testing in eight virtual acoustic scenes. Then, participants were sent home for a week with a hearing aid research platform, the Portable Hearing Lab (PHL), and instructed to seek out situations that represented their typical complex listening environments. The PHL was used to record the environment, and ecological momentary assessment was used to characterize the environment, including the location, number of noise sources, orientationof speech and noise, and access to visual cues. Acoustic, non-acoustic, and speech perception differences between virtual and real-life complex environments were compared. Although most of the complex environments in daily life were encountered at home, the virtual scenes were fairly representative in terms of the sound levels, noise sources, noise locations, and signal-to-noise ratios. Speech perception scaled similarly between the virtual environments and real life as a function of sound level and acoustic complexity. The results generally support the ecological validity of virtual acoustic scenes.

Often, designers and developers of serious games (and virtual simulations in general) strive for high fidelity (realism). However, real-time high-fidelity rendering of complex environments across sensory modalities such as vision, audition, and haptic (sense of touch) is still beyond our computational reach. Previous work has demonstrated that multimodal effects can be considerable, to the extent that a large amount of detail of one sense may be ignored or enhanced by the presence of other sensory inputs. Taking advantage of such multimodal effects, perceptual-based rendering—whereby the rendering parameters are adjusted based on the perceptual system—can be employed to limit computational processing. Motivated by the general lack of emphasis given to the understanding of audio rendering in virtual environments and games, we have started investigating multimodal (audiovisual) interactions within such virtual environments. Our work has shown that sound can directly affect visual fidelity perception and task performance within a virtual environment. These effects can be very individualized, whereby the influence of sound is dependent on various individual factors including musical listening preferences, suggesting the importance of individualizing the virtual environment to each user. This chapter begins with an overview of virtual environments and serious gaming’s open problems, with an emphasis on fidelity, and multimodal interactions, and the implications that these may have on performance and computational requirements. A detailed summary of our own prior work will be provided along with insight and suggestions that may guide designers and developers of serious games and virtual learning environments in general. Although the chapter is contextualized in the use of serious games in health professions education, the information provided is generalizable across a variety of domains.

Accurate sound rendering can add significant realism to complement visual display in interactive applications, as well as facilitate acoustic predictions for many engineering applications, like accurate acoustic analysis for architectural design. Numerical simulation can provide this realism most naturally by modeling the underlying physics of wave propagation. However, wave simulation has traditionally posed a tough computational challenge. In this paper, we present a technique which relies on an adaptive rectangular decomposition of 3D scenes to enable efficient and accurate simulation of sound propagation in complex virtual environments. It exploits the known analytical solution of the Wave Equation in rectangular domains, and utilizes an efficient implementation of the Discrete Cosine Transform on Graphics Processors (GPU) to achieve at least a 100-fold performance gain compared to a standard Finite-Difference Time-Domain (FDTD) implementation with comparable accuracy, while also being 10-fold more memory efficient. Consequently, we are able to perform accurate numerical acoustic simulation on large, complex scenes in the kilohertz range. To the best of our knowledge, it was not previously possible to perform such simulations on a desktop computer. Our work thus enables acoustic analysis on large scenes and auditory display for complex virtual environments on commodity hardware.

Purpose:The aim of the article is to propose the studies and analyses schema considering the psychophysical state of the simulator's users.Within the project a simulator and a virtual environment that allow a group of people (e.g.security guard officers) with real equipment such as cars to train different scenarios are built.The simulator users are interacting both with other colleagues and virtual surroundings.It implies that classical methods of so-called simulator sickness measurement should be adopted to the type of interaction that we call man-manmachine interaction.Design/methodology/approach: Simulator sickness that manifests itself in physiological ailments is considered in an interdisciplinary approach with particular emphasis on psychological aspects such as coping with stress, anxiety or cognitive and visual techniques related to the combined static and dynamic platforms.The main methods for the research are psychological Paper-and-Pencil surveys, eye-tracking technics, postural equilibrium tests, Poppelreuter test and Simulator Sickness Questionnaire.Findings: The result is studies and analyses schema related to the simulator users' psychophysical state appearing in the project 'Virtual Simulator of Actions of the Polish Government Protection Office'. Research limitations/implications:The research is limited to simulators specified in purpose section.Practical implications: It is anticipated that more accurate selection of individuals for security services will be possible through the use of the proposed research and diagnostic methods and analysis of the results obtained.Social implications: It is provided that more specific choice of people for security services will result in better training of the staff, an increase of the sense of security of the protected people as well as their quality of life.Originality/value: The novelty of the article is an interdisciplinary approach to the study of simulator sickness which takes into account physiological, psychological, social (group work) and technical (type of simulator) aspects.

Complex virtual environments can be simulated with physical or procedural motion. Physical motion is more realistic, but requires the integration of an ordinary differential equation from an initial state. Procedural motion has the advantage of being randomly accessible, though it is not physically based. We combine these techniques into a multiresolution model. A coarse-level simulation is sampled to yield keyframes. Then a physical motion between keyframes is calculated and distorted to meet its boundary conditions. We demonstrate these ideas with a simple virtual world consisting of wind blowing trees and leaves that can be entered and experienced efficiently at any point in time.

Virtual surgery is a typical application of virtual reality technology in the medical field, which can help improve the success rate of surgery and reduce medical costs in various aspects such as medical training, surgery planning, and intraoperative navigation, and is becoming a hot research topic and a frontier subject in the medical field. The establishment of virtual surgery simulation system involves the intersection and penetration of various disciplines, and the research is difficult, and many functional modules are still not perfect. This study focuses on the key technologies in the virtual surgery simulation system, focusing on two core modules, the soft tissue modeling method and the collision detection algorithm, to improve the accuracy of the soft tissue model deformation under the condition of meeting the real-time system. The biomechanical properties of soft tissues are studied, the viscoelastic properties are analyzed, and the viscoelastic theory is used as the basis for soft tissue modeling; the geometric model is established by using a complementary method of surface model and tetrahedral mesh cells, with the surface model covering the outer surface for visual rendering and the tetrahedral mesh cells for skeleton support of the physical model, so that the model has a better visual effect and deformation effect, which enhances the model fidelity that is enhanced by the better visual effect and deformation effect; the soft tissue physical modeling method is summarized and summarized to lay the foundation for soft tissue model optimization. The experimental results show that the bilateral teleoperation system under analog control can give the operator a better haptic sensation (smaller value of input impedance felt by the operator when doing free motion from the robot) while ensuring good positional tracking and force tracking effects. This method solves the problems of collapse distortion and lack of viscoelastic properties of the traditional mass-spring model, and improves the accuracy of model deformation. Based on the improved algorithm, the viscoelastic hybrid filled sphere model of the liver organ is successfully established, which proves that the modeling method is feasible and effective.