Shipboard VR: from damage control to design

Virtual reality efforts in the Information Technology Division of the Naval Research Laboratory (NRL) span mission planning, rehearsal, and execution; simulation-based design; and medicine. The authors devote much of their work to ship-based applications, presenting two such efforts in the article. One project focuses on experiments in shipboard firefighting to verify the effectiveness of VR as a mission planning tool. The other project involves visualizing a preliminary design of a new Navy ship. Since that work did not extend into the actual design cycle, they can't quantify the results in terms of hours gained or costs saved. However, the design team and the program managers agreed that the VR visualization was worthwhile and provided a better understanding of the design     

Driving simulation: challenges for VR technology

Virtual driving environments represent a challenging test for virtual reality technology. We present an overview of our work on the problems of scenario and scene modeling for virtual environments (VEs) in the context of the Iowa Driving Simulator (IDS). The requirements of driving simulation-a deterministic real-time software system that integrates components for user interaction, simulation, and scenario and scene modeling-make it a valuable proving ground for VE technologies. The goal of our research is not simply to improve driving simulation, but to develop technology that benefits a wide variety of VE applications. For example, our work on authoring high-fidelity VE databases and on directable scenarios populated with believable agents also targets applications involving interaction with simulated, walking humans and training in the operation of complex machinery. This work has benefited greatly from the experience of developing components for a full-scale operational VE system like IDS, and we believe that many other proposed VE technologies would similarly benefit from such real-world testing     

The effects of static and adaptive performance feedback in game-based training

Training in virtual environments (VEs) has the potential to establish mental models and task mastery while providing a safe environment in which to practice. Performance feedback is known to contribute to this learning; however, the most effective ways to provide feedback in VEs have not been established. The present study examined the effects of differing feedback content, focusing on adaptive feedback. Participants learned search procedures during multiple missions in a VE. A control group received only a performance score after each mission. Two groups additionally received either detailed or general feedback after each mission, while two other groups received feedback that adapted based on their performance (either detailed-to-general, or general-to-detailed). Groups that received detailed feedback from the start of training had faster performance improvement than all other groups; however, all feedback groups showed improved performance and by the fourth mission performed at levels above the control group. Results suggest that detailed feedback early in the training cycle is the most beneficial for the fastest learning of new task skills in VEs.     

Formalizing the Design,Evaluation, and Application of Interaction Techniques for Immersive Virtual Environments

Immersive virtual environments (VEs) have potential in many application areas, but many complex VE systems exhibit usability and interaction problems. This is partly due to a lack of consideration or understanding of 3D interaction tasks and techniques. This paper proposes the systematic study of the design, evaluation, and application of VE interaction techniques. In this methodology, design and evaluation are based on a formal task analysis and categorization of techniques, using multiple performance measures. As a direct consequence of our use of this methodology, we also present a variety of novel designs and evaluation results with respect to interaction techniques for three common VE tasks.     

Responding to a fire emergency in a virtual environment: different patterns of action for different situations

This paper presents an experimental study of participants' response to the sudden appearance of a fire emergency in a virtual environment (VE) and of the adaptivity of their response pattern. A VE has been built in which participants meet two situations: first an explorative navigation and afterwards a hurried escape from the unexpected outbreak of fire. Fire intensity and participants' distance from the exit at the outbreak of fire have been varied as well, to create different degrees of danger and different degrees of difficulty in the task of leaving the premises. Participants' action has been collected automatically for quantitative analysis by registering each individual activation of the interaction devices (a triple button joystick). In addition, the movements in both virtual and real environment of additional groups of participants have been videorecorded for qualitative analysis. Results show that the appearance of the fire emergency triggers important changes in the way people move in the VE, and that such changes are all adaptive responses to an emergency situation. In conclusion, people show recognition of a dangerous situation in a VE and readily produce adaptive responses, making the VE suitable for emergency simulations and for use as an effective training tool.     

Responding to a fire emergency in a virtual environment: different patterns of action for different situations

This paper presents an experimental study of participants' response to the sudden appearance of a fire emergency in a virtual environment (VE) and of the adaptivity of their response pattern. A VE has been built in which participants meet two situations: first an explorative navigation and afterwards a hurried escape from the unexpected outbreak of fire. Fire intensity and participants' distance from the exit at the outbreak of fire have been varied as well, to create different degrees of danger and different degrees of difficulty in the task of leaving the premises. Participants' action has been collected automatically for quantitative analysis by registering each individual activation of the interaction devices (a triple button joystick). In addition, the movements in both virtual and real environment of additional groups of participants have been videorecorded for qualitative analysis. Results show that the appearance of the fire emergency triggers important changes in the way people move in the VE, and that such changes are all adaptive responses to an emergency situation. In conclusion, people show recognition of a dangerous situation in a VE and readily produce adaptive responses, making the VE suitable for emergency simulations and for use as an effective training tool.     

基于网络的森林灭火仿真系统研究

针对森林灭火需要多要素可同时参与的复杂性,提出基于局域网构建虚拟森林环境及其灭火仿真环境的原型系统体系结构。描述森林灭火仿真系统的联邦模型、联邦对象类、交互类和联邦成员的设计和开发过程,并就仿真系统的仿真过程及其采用的“既时间控制又时间受限”的时间管理策略作了分析。采用高层体系结构,以面向对象的编程语言VC++及OpenGL图形库为平台,完成具有可交互的森林灭火仿真原型系统的研发。     

Creating Real-Time Embodied Autonomous Agents

A challenging research area for computer graphics and virtual environments (VE) is training interpersonal interactions. In such a system, at least one person is the VE participant, while several more virtual human agents (represented by human-like, embodied models) are engaged in activities in the same virtual space. The participants, whether live or virtual, should interact as if all were real. This means that the virtual agents must have several characteristics afforded to real people, including the following:     

Enhancing virtual environment spatial awareness training and transfer through tactile and vestibular cues

Haptic interaction has been successfully incorporated into a variety of virtual environment (VE) systems, yet designing multimodal VE training systems remains challenging as each cue incorporated during training should maximise learning and training transfer. This study examined the impact of incorporating two independent, spatialised tactile cues and vestibular cues into a military VE training environment with the goal of empirically examining whether such cues could enhance performance within the training environment and also that knowledge and skills gained during training could transfer to another environment. The results showed that tactile cues enhanced spatial awareness and performance during both repeated training and within a transfer environment, yet there were costs associated when two independent tactile cues were presented during training. In addition, results suggest that spatial awareness benefits from a tactile point indicator may be impacted by vestibular cues, as performance benefits were seen when tactile cues were paired with head tracking. To fully realise training potential, it is essential to determine how best to leverage multimodal capacity of VE training systems by identifying how multimodal training cues may advance knowledge, skills and attitudes of trainees. Results from this study provide design guidelines for incorporating tactile cues in VE training environments to enhance spatial awareness.     

Virtual environments applications and applied ergonomics

The usability of virtual environments has attracted considerable efforts from ergonomists. Work has included studies of the side or after effects of participation in a virtual environment (VE) as well as the appropriateness of the Virtual Reality hardware and software interfaces and the understanding of factors which determine participant performance. Equally important for applied ergonomics is to understand how best to specify, build, implement and evaluate virtual environment solutions to everyday industrial, commercial, educational and medical problems. The potential value of ergonomics applied to virtual environments, and vice versa, are discussed. Two particular instances of VE development relevant to applied ergonomics are described - structured development and evaluation of industrial training and participatory redesign of workplaces. This paper is one of a number of contributions to a special issue on ergonomics in the study and use of virtual environments.     

EKEMAS,an agent-based geo-simulation framework to support continual planning in the real-word

In this paper, we propose an agent-based geo-simulation framework EKEMAS to assist human planners when planning under strong spatial constraints in a real large-scale space. The approach consists in drawing a parallel between the real environment (for example, a forest in fire) and the simulated environment based on GIS data. This virtual environment uses software agents which are aware of the space and equipped with advanced spatial reasoning capabilities. In addition, we suggest some enhancements for the Continual Planning approach. Our aim is to demonstrate how EKEMAS, when coupled with a continual planning approach and agent’s spatial reasoning capabilities, can assist human planners overcoming obstacles related to real world constraints: dynamic, uncertain, and spatially constrained environment. We illustrate this idea on the forest firefighting problem and we use MAGS as a simulation platform and Prometheus as a fire simulator. Finally, and since plans in the studied case (wildfire fighting) are mainly paths, we also propose a new approach based on agent geo-simulation in order to solve particular Pathfinding problems.     

Perceiving affordances in virtual reality: influence of person and environmental properties in perception of standing on virtual grounds

We evaluated the perception of affordances in virtual environments (VE). In our work, we considered the affordances for standing on a virtual slanted surface. Participants were asked to judge whether a virtual slanted surface supported upright stance. The objective was to evaluate whether this perception was possible in virtual reality (VR) and comparable to previous works conducted in real environments. We found that the perception of affordances for standing on a slanted surface in virtual reality is possible and comparable (with an underestimation) to previous studies conducted in real environments. We also found that participants were able to extract and to use virtual information about friction in order to judge whether a slanted surface supported an upright stance. Finally, results revealed that the person’s position on the slanted surface is involved in the perception of affordances for standing on virtual grounds. Taken together, our results show quantitatively that the perception of affordances can be effective in virtual environments and influenced by both environmental and person properties. Such a perceptual evaluation of affordances in VR could guide VE designers to improve their designs and to better understand the effect of these designs on VE users.     

Performance of new participants in virtual environments: The Nottingham tool for assessment of interaction in virtual environments (NAÏVE)

There is a need for an assessment tool which reliably distinguishes levels of participant performance in virtual environments (VEs) built within virtual reality (VR) systems. Such screening might be of potential users amongst a company's staff or might be carried out by human factors experimenters prior to the start of experiments in order to provide a base-line of participant competences. The Nottingham Tool for Assessment for Interaction in Virtual Environments (NAÏVE) comprises a set of VE tasks and related tests, with appropriate performance criteria levels, covering the main aspects of navigation (viewpoint) control and object manipulation and operation. Trials with test participants enabled performance levels to be set to distinguish good, adequate and poor performers and tests to be distinguished according to whether performance in the general population is evenly spread or is skewed towards success or failure.     

A study of locomotion paradigms for immersive medical simulation environments

Immersive virtual environments are increasingly used for medical training and rehearsal. Immersive environments can provide realistic context for team training, where success relies on practiced coordination between individual members. Using immersive virtual environments, medical teams can practice in situations that would otherwise be difficult or expensive to create. It has been shown that individuals perform poorly when the training environment differs significantly from practice 2005. Efforts have been made to close this gap using virtual environments. Interacting in a virtual space requires a robust locomotion paradigm. Locomotion paradigms are methods that allow an individual to move and navigate through virtual environments. Locomotion paradigms should be intuitive to the user, and not distract from the central task of medical training. In this paper, we describe and evaluate four locomotion paradigms, Look & Go, Push & Go, Point & Go, and Grab & Drag, using objective metrics to evaluate navigational efficiency. This study was performed with 98 volunteers predominantly of clinical backgrounds. With the comparison between the performances of game-playing and non-game-playing subjects, we have shown that game-playing experiences do not significantly affect the locomotion performances with the four proposed paradigms. The results of this study suggests the Grab & Drag as the best method among four locomotion paradigms in triage/trauma scenarios, where trainees need to find and help patients scattered in a large area.     

Intelligent virtual agents keeping watch in the battlefield

One of the first areas where virtual reality found a practical application was military training. Two fairly obvious reasons have driven the military to explore and employ this kind of technique in their training; to reduce exposure to hazards and to increase stealth. Many aspects of combat operations are very hazardous, and they become even more dangerous if the combatant seeks to improve his performance. Some smart weapons are autonomous, while others are remotely controlled after they are launched. This allows the shooter and weapon controller to launch the weapon and immediately seek cover, thus decreasing his exposure to return fire. Before launching a weapon, the person who controls that weapon must acquire/perceive as much information as he can, not only from its environment, but also from the people who inhabits that environment. Intelligent virtual agents (IVAs) are used in a wide variety of simulation environments, especially in order to simulate realistic situations as, for example, high fidelity virtual environment (VE) for military training that allows thousands of agents to interact in battlefield scenarios. In this paper, we propose a perceptual model, which seeks to introduce more coherence between IVA perception and human being perception, increasing the psychological coherence between the real life and the VE experience. Agents lacking this perceptual model could react in a non-realistic way, hearing or seeing things that are too far away or hidden behind other objects. The perceptual model, we propose in this paper introduces human limitations inside the agents perceptual model with the aim of reflecting human perception.     

Training in virtual environments: transfer to real world tasks and equivalence to real task training

Virtual environments (VEs) are extensively used in training but there have been few rigorous scientific investigations of whether and how skills learned in a VE are transferred to the real world. This research aimed to measure and evaluate what is transferring from training a simple sensorimotor task in a VE to real world performance. In experiment 1, real world performances after virtual training, real training and no training were compared. Virtual and real training resulted in equivalent levels of post-training performance, both of which significantly exceeded task performance without training. Experiments 2 and 3 investigated whether virtual and real trained real world performances differed in their susceptibility to cognitive and motor interfering tasks (experiment 2) and in terms of spare attentional capacity to respond to stimuli and instructions which were not directly related to the task (experiment 3). The only significant difference found was that real task performance after training in a VE was less affected by concurrently performed interference tasks than was real task performance after training on the real task. This finding is discussed in terms of the cognitive load characteristics of virtual training. Virtual training therefore resulted in equivalent or even better real world performance than real training in this simple sensorimotor task, but this finding may not apply to other training tasks. Future research should be directed towards establishing a comprehensive knowledge of what is being transferred to real world performance in other tasks currently being trained in VEs and investigating the equivalence of virtual and real trained performances in these situations.     

Training in virtual environments: transfer to real world tasks and equivalence to real task training

Virtual environments (VEs) are extensively used in training but there have been few rigorous scientific investigations of whether and how skills learned in a VE are transferred to the real world. This research aimed to measure and evaluate what is transferring from training a simple sensorimotor task in a VE to real world performance. In experiment 1, real world performances after virtual training, real training and no training were compared. Virtual and real training resulted in equivalent levels of post-training performance, both of which significantly exceeded task performance without training. Experiments 2 and 3 investigated whether virtual and real trained real world performances differed in their susceptibility to cognitive and motor interfering tasks (experiment 2) and in terms of spare attentional capacity to respond to stimuli and instructions which were not directly related to the task (experiment 3). The only significant difference found was that real task performance after training in a VE was less affected by concurrently performed interference tasks than was real task performance after training on the real task. This finding is discussed in terms of the cognitive load characteristics of virtual training. Virtual training therefore resulted in equivalent or even better real world performance than real training in this simple sensorimotor task, but this finding may not apply to other training tasks. Future research should be directed towards establishing a comprehensive knowledge of what is being transferred to real world performance in other tasks currently being trained in VEs and investigating the equivalence of virtual and real trained performances in these situations.     

消防接警员模拟训练系统设计与实现

分析消防接处警操作员训练现状,阐述建立消防接处警模拟训练系统的必要性。在此基础上,提出消防接处警模拟系统的结构框架,介绍模拟训练系统业务流程,实现模拟训练系统。本系统提高了消防接警员通过非实时系统应对各类灾害事故的消防指挥调度的效率和准确性。     

Way-finding during a fire emergency: an experimental study in a virtual environment

The way-finding behaviour and response during a fire emergency in a virtual environment (VE) was experimentally investigated. Forty participants, divided into two groups, were required to find the emergency exit as soon as possible in a virtual hotel building because of a fire escape demand under condition 1 (VE without virtual fire, control group) and condition 2 (VE with virtual fire, treatment group). Compared to the control group, the treatment group induced significantly higher skin conductivity and heart rate, experienced more stress, took longer time to notice the evacuation signs, had quicker visual search and had a longer escape time to find the exit. These results indicated that the treatment condition induced higher physiological and psychological stress, and had influenced the escape behaviour compared to the control group. In practice, fire evacuation education and fire evacuation system design should consider the response characteristics in a fire emergency.