Background Over the last few years,the rapid advancement of technology has led to the development of many approaches to digitalization.In this respect,metaverse provides 3D persistent virtual environments that can be ...Background Over the last few years,the rapid advancement of technology has led to the development of many approaches to digitalization.In this respect,metaverse provides 3D persistent virtual environments that can be used to access digital content,meet virtually,and perform several professional and leisure tasks.Among the numerous technologies supporting the metaverse,immersive Virtual Reality(VR)plays a primary role and offers highly interactive social experiences.Despite growing interest in this area,there are no clear design guidelines for creating environments tailored to the metaverse.Methods This study seeks to advance research in this area by moving from state-of-the-art studies on the design of immersive virtual environments in the context of metaverse and proposing how to integrate cutting-edge technologies within this context.Specifically,the best practices were identified by i)analyzing literature studies focused on human behavior in immersive virtual environments,ii)extracting common features of existing social VR platforms,and iii)conducting interviews with experts in a specific application domain.Specifically,this study considered the creation of a new virtual environment for MetaLibrary,a VR-based social platform aimed at integrating public libraries into metaverse.Several implementation challenges and additional requirements have been identified for the development of virtual environments(VEs).These elements were considered in the selection of specific cutting-edge technologies and their integration into the development process.A user study was also conducted to investigate some design aspects(namely lighting conditions and richness of the scene layout)for which deriving clear indications from the above analysis was not possible because different alternative configurations could be chosen.Results The work reported in this paper seeks to bridge the gap between existing VR platforms and related literature in the field,on the one hand,and requirements regarding immersive virtual environments for the metaverse,on the other hand,by reporting a set of best practices which were used to build a social virtual environment that meets users'expectations and needs.Conclusions Results suggest that carefully designed virtual environments can positively affect user experience and interaction within metaverse.The insights gained from this study offer valuable cues for developing immersive virtual environments for the metaverse to deliver more effective and engaging experiences.展开更多
BACKGROUND Preschoolers become anxious when they are about to undergo anesthesia and surgery,warranting the development of more appropriate and effective interventions.AIM To explore the effect of static cartoons comb...BACKGROUND Preschoolers become anxious when they are about to undergo anesthesia and surgery,warranting the development of more appropriate and effective interventions.AIM To explore the effect of static cartoons combined with dynamic virtual environments on preoperative anxiety and anesthesia induction compliance in preschool-aged children undergoing surgery.METHODS One hundred and sixteen preschool-aged children were selected and assigned to the drug(n=37),intervention(n=40),and control(n=39)groups.All the children received routine preoperative checkups and nursing before being transferred to the preoperative preparation room on the day of the operation.The drug group received 0.5 mg/kg midazolam and the intervention group treatment consisting of static cartoons combined with dynamic virtual environments.The control group received no intervention.The modified Yale Preoperative Anxiety Scale was used to evaluate the children’s anxiety level on the day before surgery(T0),before leaving the preoperative preparation room(T1),when entering the operating room(T2),and at anesthesia induction(T3).Compliance during anesthesia induction(T3)was evaluated using the Induction Compliance Checklist(ICC).Changes in mean arterial pressure(MAP),heart rate(HR),and respiratory rate(RR)were also recorded at each time point.RESULTS The anxiety scores of the three groups increased variously at T1 and T2.At T3,both the drug and intervention groups had similar anxiety scores,both of which were lower than those in the control group.At T1 and T2,MAP,HR,and RR of the three groups increased.The drug and control groups had significantly higher MAP and RR than the intervention group at T2.At T3,the MAP,HR,and RR of the drug group decreased and were significantly lower than those in the control group but were comparable to those in the intervention group.Both the drug and intervention groups had similar ICC scores and duration of anesthesia induction(T3),both of which were higher than those of the control group.CONCLUSION Combining static cartoons with dynamic virtual environments as effective as medication,specifically midazolam,in reducing preoperative anxiety and fear in preschool-aged children.This approach also improve their compliance during anesthesia induction and helped maintain their stable vital signs.展开更多
Virtual reality (VR) is a rapidly developing technology that has a wide spectrum of industrial and commercial applications. Networked (distributed or shared) virtual environments (VE) are of growing interest to modern...Virtual reality (VR) is a rapidly developing technology that has a wide spectrum of industrial and commercial applications. Networked (distributed or shared) virtual environments (VE) are of growing interest to modern manufacturing industry; a dominating use of networked virtual manufacturing environments (VMEs) is on-line visualisation and collaborative control of 3D information. This has to be supported by real-time data transfer. To meet a broad range of common requirements for Internet-based VE communications, particularly for virtual manufacturing and collaborative design and control, this paper presents a networked virtual environment system that is designed to support networked virtual design and manufacturing. The system is implemented with manufacturing message specification (MMS) standards so as to integrate a range of manufacturing services into networked VEs over the Internet.展开更多
This paper presents research into applying virtual environment (VE) technology to supply chain management (SCM). Our research work has employed virtual manufacturing environments to represent supply chain nodes to sim...This paper presents research into applying virtual environment (VE) technology to supply chain management (SCM). Our research work has employed virtual manufacturing environments to represent supply chain nodes to simulate processes and activities in supply chain management. This will enable those who are involved in these processes and activities to gain an intuitive understanding of them, so as to design robust supply chains and make correct decisions at the right time. A framework system and its hierarchical structure for visualising and simulating supply chains in virtual environments are reported and detailed in this paper.展开更多
In this paper, we present a framework for the generation and control of an Internet-based 3-dimensional game virtual environment that allows a character to navigate through the environment. Our framework includes 3-di...In this paper, we present a framework for the generation and control of an Internet-based 3-dimensional game virtual environment that allows a character to navigate through the environment. Our framework includes 3-dimensional terrain mesh data processing, a map editor, scene processing, collision processing, and walkthrough control. We also define an environment-specific semantic information editor, which can be applied using specific location obtained from the real world. Users can insert text information related to the characters real position in the real world during navigation in the game virtual environment.展开更多
This paper presents the design and implementation of reconfigurable virtual environments (VEs) for virtual testing. It proposes a hybrid design approach that is derived from a so-called integration and composition of ...This paper presents the design and implementation of reconfigurable virtual environments (VEs) for virtual testing. It proposes a hybrid design approach that is derived from a so-called integration and composition of the reconfiguration strategy. The designing process has thus evolved from binding virtual objects using reconfiguration rules within the context of virtual testing scenarios. Therefore reconfigurable virtual environments are established with improved flexibility and scalability, tailored to a wide range of virtual testing applications. Those virtual environments integrate virtual testing scenarios, data acquisition, databases, rule mapping and application interfaces, which yield modular testing functions and an open-ended system architecture with a set of extensible interface tools to realize data exchange within reconfigurable VEs. This enables virtual testing scenarios to be reconfigured interactively based on real time data and communication between virtual environments and real environments. A virtual testing application has been implemented using reconfigurable VEs. Keywords Virtual environment - virtual testing - reconfigurable virtual reality Wenyan Wu graduated from Dalian University of Technology, China, with BSc and MSc in 1988 and 1991 respectively. She earned her PhD degree from University of Derby, UK, in 2002. She had taught and researched in Harbin Institute of Technology, China and De Montfort University, UK. She is currently a senior lecturer in simulation and virtual reality at Staffordshire University, UK. Her research interests include computer graphics, Virtual Reality and Augmented Reality system, advanced interface, modelling and simulation, distribution system.Zhengxu Zhao BSc, MSc, PhD, CEng, CITP, MBCS, full Professor in Applied Computing, Director of Virtual Reality Centre. He is also a Cheng Kong Scholar Project Professor in Virtual Reality Technology and Director of Virtual Reality Research Centre at the Southeast University, P R China. Professor Zhao’s research interests include computing graphics and VR systems, industrial process simulation, CIM and manufacturing management systems.展开更多
Mobile agents provide a new method for the distributed computation. This paper presents the advantages of using mobile agents in a distributed virtual environment (DVE) system, and describes the architecture of hetero...Mobile agents provide a new method for the distributed computation. This paper presents the advantages of using mobile agents in a distributed virtual environment (DVE) system, and describes the architecture of heterogeneous computer's distributed virtual environment system (HCWES) designed to populate some mobile agents as well as stationary agents. Finally, the paper introduces how heterogeneous computer network communication is to be realized.展开更多
This paper first introduces a way to improve interactivity with high polygon count virtual objects through the "mixed" use of image-based representation within one object. That is, both 3D polygonal and imag...This paper first introduces a way to improve interactivity with high polygon count virtual objects through the "mixed" use of image-based representation within one object. That is, both 3D polygonal and image-based representations are maintained for an object, and switched for rendering depending on the functional requirement of the object. Furthermore, in order to reduce the popping effect and provide smooth and gradual transition during the object representation switch, the object is subdivided with the subdivided parts possibly represented differently, i.e., using 3D models or images. As for the image-based representation, the relief texture (RT) method is used. In particular, through the use of the mixed representation, a new way called TangibleScreen is pro-posed to provide object tangibility by associating the image-based representation with a physical prop (projecting the RTs) in a selective and flexible way. Overall, the proposed method provides a way to maintain an interactive frame rate with selective perceptual details in a large-scale virtual environment, while allowing the user to interact with virtual objects in a tangible way.展开更多
The sense of being within a three-dimensional （3D） space and interacting with virtual 3D objects in a computer-generated virtual environment （VE） often requires essential image, vision and sensor signal processing...The sense of being within a three-dimensional （3D） space and interacting with virtual 3D objects in a computer-generated virtual environment （VE） often requires essential image, vision and sensor signal processing techniques such as differentiating and denoising. This paper describes novel implementations of the Gaussian filtering for characteristic signal extraction and waveletbased image denoising algorithms that run on the graphics processing unit （GPU）. While significant acceleration over standard CPU implementations is obtained through exploiting data parallelism provided by the modern programmable graphics hardware, the CPU can be freed up to run other computations more efficiently such as artificial intelligence （AI） and physics. The proposed GPU-based Gaussian filtering can extract surface information from a real object and provide its material features for rendering and illumination. The wavelet-based signal denoising for large size digital images realized in this project provided better realism for VE visualization without sacrificing real-time and interactive performances of an application.展开更多
Studies the design of distributed virtual environments （DVEs） for tele-multi-robotics. The proposed design, incorporating two models （ distributlon-supported model and VE-supported model）, attempts to represent co...Studies the design of distributed virtual environments （DVEs） for tele-multi-robotics. The proposed design, incorporating two models （ distributlon-supported model and VE-supported model）, attempts to represent common functionality, communication issues, and requirements found in multi-operator DVEs. The distribution-supported model concentrates on the introduction of computer-supported collaborative work （CSCW） to realize the coordination of multi-operators, while the VE-supported model concentrates on the utilization of an object-oriented approach to strengthen the expandability and robustness of the system. Finally, the configuration anti running environments of the system are given.展开更多
Virtual environment has been widely applied in scientific research and considered as an important tool of exploring science. But constructing a real virtual environment is rather difficult. The difficulty cannot be co...Virtual environment has been widely applied in scientific research and considered as an important tool of exploring science. But constructing a real virtual environment is rather difficult. The difficulty cannot be compared with developing general software. It has a high demand for software technology. Obviously traditional methods are not competent for the job. Fortunately with the development of agent-oriented technologies, all problems seem to be solved. By classifying a virtual environment into four layers corresponding with real world and considering it as a collection of agents, the virtual objects can be mapped into agents and an agent model can be designed. Based on the idea that the state change of a system is caused by that of individuals and the mutual effect among them, a theory of agent behavior driven by event and belief is put forward. Such agent-oriented modeling method can cope with the demand for handling multi-dimension information. It is an effective technique for constructing a large and complex virtual environment.展开更多
The simulation of human in the distributed virtual environment is different from the simulation of vehicle. Due to the human’s many joints, to implement the real time performance of the interaction between the virtua...The simulation of human in the distributed virtual environment is different from the simulation of vehicle. Due to the human’s many joints, to implement the real time performance of the interaction between the virtual human and the environment, the quantity of information broadcasted in the network will be increased. So with the growing of the quantity of virtual human added to the network, the network burthen would augment rapidly. Therefore, for the simulation of virtual human this paper divides organically the motion parts of the body, which makes those body parts that often interact with the environment are described according to the joints while other parts are described according to the action information. Simultaneity, this paper adopts Dead Reckoning to reduce the quantity of information needed by maintaining the reality motion of virtual human. The experiment indicates that the forecasting display technique can efficiently reduce the network burthen and enhance the interaction of virtual human.展开更多
The inherent complexity and uncertainty of multi-operator multi-robot （MOMR） tele-operation system make its safeguard an essential problem. Hazardous factors in the system are analyzed using fault tree analysis（FTA...The inherent complexity and uncertainty of multi-operator multi-robot （MOMR） tele-operation system make its safeguard an essential problem. Hazardous factors in the system are analyzed using fault tree analysis（FTA） technology, and three-layer interactive safety architecture with information flow is designed in modules to control the factors according to the holistic control mode. After that, distributed virtual environment （DVE） including the characteristics of virtual guide （VG） technology is discussed to help the operators achieve some tasks through the visibility of control commands, time-delay, movement collision and operators＇ intentions. Finally an experiment is implemented to test the efficiency of safety control architecture by using two robots to place some building blocks in the same workspace.展开更多
The trustworthiness of virtual machines is a big security issue in cloud computing. In this paper, we aimed at designing a practical trustworthiness mechanism in virtual environment. With the assist of a third certifi...The trustworthiness of virtual machines is a big security issue in cloud computing. In this paper, we aimed at designing a practical trustworthiness mechanism in virtual environment. With the assist of a third certificate agent, the cloud user generates a trust base and extends it to its VMs. For each service running on the VM, a hash value is generated from all the necessary modules, and these hash values are organized and maintained with a specially designed hash tree whose root is extended from the user's trust base. Before the VM loads a service, the hash tree is verified from the coordinated hash value to check the trustworthiness of the service.展开更多
Background Physical entity interactions in mixed reality(MR)environments aim to harness human capabilities in manipulating physical objects,thereby enhancing virtual environment(VEs)functionality.In MR,a common strate...Background Physical entity interactions in mixed reality(MR)environments aim to harness human capabilities in manipulating physical objects,thereby enhancing virtual environment(VEs)functionality.In MR,a common strategy is to use virtual agents as substitutes for physical entities,balancing interaction efficiency with environmental immersion.However,the impact of virtual agent size and form on interaction performance remains unclear.Methods Two experiments were conducted to explore how virtual agent size and form affect interaction performance,immersion,and preference in MR environments.The first experiment assessed five virtual agent sizes(25%,50%,75%,100%,and 125%of physical size).The second experiment tested four types of frames(no frame,consistent frame,half frame,and surrounding frame)across all agent sizes.Participants,utilizing a head mounted display,performed tasks involving moving cups,typing words,and using a mouse.They completed questionnaires assessing aspects such as the virtual environment effects,interaction effects,collision concerns,and preferences.Results Results from the first experiment revealed that agents matching physical object size produced the best overall performance.The second experiment demonstrated that consistent framing notably enhances interaction accuracy and speed but reduces immersion.To balance efficiency and immersion,frameless agents matching physical object sizes were deemed optimal.Conclusions Virtual agents matching physical entity sizes enhance user experience and interaction performance.Conversely,familiar frames from 2D interfaces detrimentally affect interaction and immersion in virtual spaces.This study provides valuable insights for the future development of MR systems.展开更多
Background Fibromyalgia(FM)is a chronic rheumatic disorder characterised by musculoskeletal pain,fatigue,and psychoemotional symptoms.Virtual reality(VR)has proven to be an innovative and motivating tool for managing ...Background Fibromyalgia(FM)is a chronic rheumatic disorder characterised by musculoskeletal pain,fatigue,and psychoemotional symptoms.Virtual reality(VR)has proven to be an innovative and motivating tool for managing FM,with several studies indicating that it can improve quality of life indices and reduce psychoemotional symptoms.However,studies on immersive VR-based exercise(iVRE)are limited.Methods The aim of this study was to evaluate the effects of iVRE on quality of life,stress,anxiety,depression,and handgrip strength in patients with FM.A single-arm pre-post-test pilot study was conducted.Individuals diagnosed with FM were recruited using convenience sampling.The iVRE protocol consisted of 12 sessions of 10 min warm-up and 15 min exercises applied with the Oculus Quest 2TM device.The impact on quality of life was assessed using the Revised Fibromyalgia Impact Questionnaire,and the effects on stress,anxiety,and depression were determined using the Depression Anxiety Stress Scale-21 questionnaire.Handgrip strength was evaluated using the Baseline®dynamometer.The normality assumption was evaluated,and the pre-post means were compared using Student's ttest(p<0.05).Results Eleven individuals(40.6±11.2 years)completed the protocol(10 women).There were significant differences in favour of iVRE in quality of life impact(p<0.001,Cohen's d:1.48),handgrip strength(p<0.05,Cohen's d:0.26),depression(p<0.05,Cohen's d:0.73),and anxiety(p<0.05,Cohen's d:0.73).Conclusions A six-week iVRE program significantly reduces the impact on quality of life,anxiety,and depression and improves handgrip strength in people with FM.Future studies should investigate the physiological effects using systemic biomarkers to explain the scope of this therapeutic modality.展开更多
Daylighting plays an eminent role in the performance of indoor environments and their occupants,thus necessitating the need to investigate daylight perception of potential occupants at early design stages.The present ...Daylighting plays an eminent role in the performance of indoor environments and their occupants,thus necessitating the need to investigate daylight perception of potential occupants at early design stages.The present study introduces an interactive approach to collect and visualize brightness perception of daylighting in a large-scale immersive virtual environment using a game engine as a daylight simulation tool.The developed system allows users to explore building models freely at different day times set in virtual reality and report their perceptions in real time.Following a validation study(N=36)to investigate the consistency of brightness perceptions in a real environment and its virtual replica,a set of 24 participants were recruited to use the system to report their brightness perception in a virtual model of a daylit art museum,through snapshotting the scenes where they perceive as one of the following in terms of daylighting:(very dark,dark,bright,or very bright).Using an output of 419 snapshots,a"Perceptual Light Map"(PLM)was developed to visualize the collective brightness perception of participants as a heat map.Subjective responses were found to be positively correlated with four daylight metrics,with the highest correlation to mean luminance and the lowest to luminance ratio.The findings of this exploratory study represent a step towards a user-oriented supplement tool to the existing quantitative daylight metrics,validating game engines’adequacy as a daylight simulation tool,and illustrating the potentials of immersion and interaction principles for the perception of daylit spaces in virtual reality.展开更多
Virtual reality(VR)is a frequently emphasized issue on the Digital Earth(DE)agenda.While current DE research is more engaged in the technical aspects of VR applications,this paper focuses on what is possible with imme...Virtual reality(VR)is a frequently emphasized issue on the Digital Earth(DE)agenda.While current DE research is more engaged in the technical aspects of VR applications,this paper focuses on what is possible with immersive virtual environments(IVE)from the user’s perspective.After a brief discussion of spatial presence and embodiment in the context of IVE,both concepts will be merged into a geovisualization immersion pipeline(GIP)as a framework with which to systematically link technical and cognitive aspects of IVE.We will then analyze the general criteria that must be met by IVE in order to facilitate the experience of spatial presence.Adapting these criteria to the special requirements of geospatial data,a definition of geovisualization immersive virtual environments(GeoIVE)is formulated.Finally,the theoretical considerations of this paper are set into practice,using a GeoIVE of a coral reef ecosystem as an example.As we shall see,while GIS do not provide data models or data compatibility for direct visualization of GeoIVE on VR output devices,game engines can serve as middleware to fill this gap.展开更多
An Augmented virtual environment(AVE)is concerned with the fusion of real-time video with 3D models or scenes so as to augment the virtual environment.In this paper,a new approach to establish an AVE with a wide field...An Augmented virtual environment(AVE)is concerned with the fusion of real-time video with 3D models or scenes so as to augment the virtual environment.In this paper,a new approach to establish an AVE with a wide field of view is proposed,including real-time video projection,multiple video texture fusion and 3D visualization of moving objects.A new diagonally weighted algorithm is proposed to smooth the apparent gaps within the overlapping area between the two adjacent videos.A visualization method for the location and trajectory of a moving virtual object is proposed to display the moving object and its trajectory in the 3D virtual environment.The experimental results showed that the proposed set of algorithms are able to fuse multiple real-time videos with 3D models efficiently,and the experiment runs a 3D scene containing two million triangles and six real-time videos at around 55 frames per second on a laptop with 1GB of graphics card memory.In addition,a realistic AVE with a wide field of view was created based on the Digital Earth Science Platform by fusing three videos with a complex indoor virtual scene,visualizing a moving object and drawing its trajectory in the real time.展开更多
基金Supported by Fondazione TIM in the context of the “Facciamola Facile” initiativeby Programma Operativo Nazionale (PON)“Ricerca e Innovazione” 2014-2020-DM 1062/2021 funds
文摘Background Over the last few years,the rapid advancement of technology has led to the development of many approaches to digitalization.In this respect,metaverse provides 3D persistent virtual environments that can be used to access digital content,meet virtually,and perform several professional and leisure tasks.Among the numerous technologies supporting the metaverse,immersive Virtual Reality(VR)plays a primary role and offers highly interactive social experiences.Despite growing interest in this area,there are no clear design guidelines for creating environments tailored to the metaverse.Methods This study seeks to advance research in this area by moving from state-of-the-art studies on the design of immersive virtual environments in the context of metaverse and proposing how to integrate cutting-edge technologies within this context.Specifically,the best practices were identified by i)analyzing literature studies focused on human behavior in immersive virtual environments,ii)extracting common features of existing social VR platforms,and iii)conducting interviews with experts in a specific application domain.Specifically,this study considered the creation of a new virtual environment for MetaLibrary,a VR-based social platform aimed at integrating public libraries into metaverse.Several implementation challenges and additional requirements have been identified for the development of virtual environments(VEs).These elements were considered in the selection of specific cutting-edge technologies and their integration into the development process.A user study was also conducted to investigate some design aspects(namely lighting conditions and richness of the scene layout)for which deriving clear indications from the above analysis was not possible because different alternative configurations could be chosen.Results The work reported in this paper seeks to bridge the gap between existing VR platforms and related literature in the field,on the one hand,and requirements regarding immersive virtual environments for the metaverse,on the other hand,by reporting a set of best practices which were used to build a social virtual environment that meets users'expectations and needs.Conclusions Results suggest that carefully designed virtual environments can positively affect user experience and interaction within metaverse.The insights gained from this study offer valuable cues for developing immersive virtual environments for the metaverse to deliver more effective and engaging experiences.
基金Supported by Hangzhou Medical and Health Technology Project,No.OO20191141。
文摘BACKGROUND Preschoolers become anxious when they are about to undergo anesthesia and surgery,warranting the development of more appropriate and effective interventions.AIM To explore the effect of static cartoons combined with dynamic virtual environments on preoperative anxiety and anesthesia induction compliance in preschool-aged children undergoing surgery.METHODS One hundred and sixteen preschool-aged children were selected and assigned to the drug(n=37),intervention(n=40),and control(n=39)groups.All the children received routine preoperative checkups and nursing before being transferred to the preoperative preparation room on the day of the operation.The drug group received 0.5 mg/kg midazolam and the intervention group treatment consisting of static cartoons combined with dynamic virtual environments.The control group received no intervention.The modified Yale Preoperative Anxiety Scale was used to evaluate the children’s anxiety level on the day before surgery(T0),before leaving the preoperative preparation room(T1),when entering the operating room(T2),and at anesthesia induction(T3).Compliance during anesthesia induction(T3)was evaluated using the Induction Compliance Checklist(ICC).Changes in mean arterial pressure(MAP),heart rate(HR),and respiratory rate(RR)were also recorded at each time point.RESULTS The anxiety scores of the three groups increased variously at T1 and T2.At T3,both the drug and intervention groups had similar anxiety scores,both of which were lower than those in the control group.At T1 and T2,MAP,HR,and RR of the three groups increased.The drug and control groups had significantly higher MAP and RR than the intervention group at T2.At T3,the MAP,HR,and RR of the drug group decreased and were significantly lower than those in the control group but were comparable to those in the intervention group.Both the drug and intervention groups had similar ICC scores and duration of anesthesia induction(T3),both of which were higher than those of the control group.CONCLUSION Combining static cartoons with dynamic virtual environments as effective as medication,specifically midazolam,in reducing preoperative anxiety and fear in preschool-aged children.This approach also improve their compliance during anesthesia induction and helped maintain their stable vital signs.
文摘Virtual reality (VR) is a rapidly developing technology that has a wide spectrum of industrial and commercial applications. Networked (distributed or shared) virtual environments (VE) are of growing interest to modern manufacturing industry; a dominating use of networked virtual manufacturing environments (VMEs) is on-line visualisation and collaborative control of 3D information. This has to be supported by real-time data transfer. To meet a broad range of common requirements for Internet-based VE communications, particularly for virtual manufacturing and collaborative design and control, this paper presents a networked virtual environment system that is designed to support networked virtual design and manufacturing. The system is implemented with manufacturing message specification (MMS) standards so as to integrate a range of manufacturing services into networked VEs over the Internet.
基金This work is partially sponsored by the Cheung Kong Scholars Programme of the People's Republic of China.
文摘This paper presents research into applying virtual environment (VE) technology to supply chain management (SCM). Our research work has employed virtual manufacturing environments to represent supply chain nodes to simulate processes and activities in supply chain management. This will enable those who are involved in these processes and activities to gain an intuitive understanding of them, so as to design robust supply chains and make correct decisions at the right time. A framework system and its hierarchical structure for visualising and simulating supply chains in virtual environments are reported and detailed in this paper.
文摘In this paper, we present a framework for the generation and control of an Internet-based 3-dimensional game virtual environment that allows a character to navigate through the environment. Our framework includes 3-dimensional terrain mesh data processing, a map editor, scene processing, collision processing, and walkthrough control. We also define an environment-specific semantic information editor, which can be applied using specific location obtained from the real world. Users can insert text information related to the characters real position in the real world during navigation in the game virtual environment.
文摘This paper presents the design and implementation of reconfigurable virtual environments (VEs) for virtual testing. It proposes a hybrid design approach that is derived from a so-called integration and composition of the reconfiguration strategy. The designing process has thus evolved from binding virtual objects using reconfiguration rules within the context of virtual testing scenarios. Therefore reconfigurable virtual environments are established with improved flexibility and scalability, tailored to a wide range of virtual testing applications. Those virtual environments integrate virtual testing scenarios, data acquisition, databases, rule mapping and application interfaces, which yield modular testing functions and an open-ended system architecture with a set of extensible interface tools to realize data exchange within reconfigurable VEs. This enables virtual testing scenarios to be reconfigured interactively based on real time data and communication between virtual environments and real environments. A virtual testing application has been implemented using reconfigurable VEs. Keywords Virtual environment - virtual testing - reconfigurable virtual reality Wenyan Wu graduated from Dalian University of Technology, China, with BSc and MSc in 1988 and 1991 respectively. She earned her PhD degree from University of Derby, UK, in 2002. She had taught and researched in Harbin Institute of Technology, China and De Montfort University, UK. She is currently a senior lecturer in simulation and virtual reality at Staffordshire University, UK. Her research interests include computer graphics, Virtual Reality and Augmented Reality system, advanced interface, modelling and simulation, distribution system.Zhengxu Zhao BSc, MSc, PhD, CEng, CITP, MBCS, full Professor in Applied Computing, Director of Virtual Reality Centre. He is also a Cheng Kong Scholar Project Professor in Virtual Reality Technology and Director of Virtual Reality Research Centre at the Southeast University, P R China. Professor Zhao’s research interests include computing graphics and VR systems, industrial process simulation, CIM and manufacturing management systems.
文摘Mobile agents provide a new method for the distributed computation. This paper presents the advantages of using mobile agents in a distributed virtual environment (DVE) system, and describes the architecture of heterogeneous computer's distributed virtual environment system (HCWES) designed to populate some mobile agents as well as stationary agents. Finally, the paper introduces how heterogeneous computer network communication is to be realized.
基金Project (No. R01-2006-000-11142-0) supported by the "Teukjung Gicho" Program of the Korea Science Foundation
文摘This paper first introduces a way to improve interactivity with high polygon count virtual objects through the "mixed" use of image-based representation within one object. That is, both 3D polygonal and image-based representations are maintained for an object, and switched for rendering depending on the functional requirement of the object. Furthermore, in order to reduce the popping effect and provide smooth and gradual transition during the object representation switch, the object is subdivided with the subdivided parts possibly represented differently, i.e., using 3D models or images. As for the image-based representation, the relief texture (RT) method is used. In particular, through the use of the mixed representation, a new way called TangibleScreen is pro-posed to provide object tangibility by associating the image-based representation with a physical prop (projecting the RTs) in a selective and flexible way. Overall, the proposed method provides a way to maintain an interactive frame rate with selective perceptual details in a large-scale virtual environment, while allowing the user to interact with virtual objects in a tangible way.
基金supported by Research Funding of Huddersfield University:GPU-based High Performance Computing for Signal Processing (No. 1008/REU117)
文摘The sense of being within a three-dimensional （3D） space and interacting with virtual 3D objects in a computer-generated virtual environment （VE） often requires essential image, vision and sensor signal processing techniques such as differentiating and denoising. This paper describes novel implementations of the Gaussian filtering for characteristic signal extraction and waveletbased image denoising algorithms that run on the graphics processing unit （GPU）. While significant acceleration over standard CPU implementations is obtained through exploiting data parallelism provided by the modern programmable graphics hardware, the CPU can be freed up to run other computations more efficiently such as artificial intelligence （AI） and physics. The proposed GPU-based Gaussian filtering can extract surface information from a real object and provide its material features for rendering and illumination. The wavelet-based signal denoising for large size digital images realized in this project provided better realism for VE visualization without sacrificing real-time and interactive performances of an application.
文摘Studies the design of distributed virtual environments （DVEs） for tele-multi-robotics. The proposed design, incorporating two models （ distributlon-supported model and VE-supported model）, attempts to represent common functionality, communication issues, and requirements found in multi-operator DVEs. The distribution-supported model concentrates on the introduction of computer-supported collaborative work （CSCW） to realize the coordination of multi-operators, while the VE-supported model concentrates on the utilization of an object-oriented approach to strengthen the expandability and robustness of the system. Finally, the configuration anti running environments of the system are given.
文摘Virtual environment has been widely applied in scientific research and considered as an important tool of exploring science. But constructing a real virtual environment is rather difficult. The difficulty cannot be compared with developing general software. It has a high demand for software technology. Obviously traditional methods are not competent for the job. Fortunately with the development of agent-oriented technologies, all problems seem to be solved. By classifying a virtual environment into four layers corresponding with real world and considering it as a collection of agents, the virtual objects can be mapped into agents and an agent model can be designed. Based on the idea that the state change of a system is caused by that of individuals and the mutual effect among them, a theory of agent behavior driven by event and belief is put forward. Such agent-oriented modeling method can cope with the demand for handling multi-dimension information. It is an effective technique for constructing a large and complex virtual environment.
文摘The simulation of human in the distributed virtual environment is different from the simulation of vehicle. Due to the human’s many joints, to implement the real time performance of the interaction between the virtual human and the environment, the quantity of information broadcasted in the network will be increased. So with the growing of the quantity of virtual human added to the network, the network burthen would augment rapidly. Therefore, for the simulation of virtual human this paper divides organically the motion parts of the body, which makes those body parts that often interact with the environment are described according to the joints while other parts are described according to the action information. Simultaneity, this paper adopts Dead Reckoning to reduce the quantity of information needed by maintaining the reality motion of virtual human. The experiment indicates that the forecasting display technique can efficiently reduce the network burthen and enhance the interaction of virtual human.
文摘The inherent complexity and uncertainty of multi-operator multi-robot （MOMR） tele-operation system make its safeguard an essential problem. Hazardous factors in the system are analyzed using fault tree analysis（FTA） technology, and three-layer interactive safety architecture with information flow is designed in modules to control the factors according to the holistic control mode. After that, distributed virtual environment （DVE） including the characteristics of virtual guide （VG） technology is discussed to help the operators achieve some tasks through the visibility of control commands, time-delay, movement collision and operators＇ intentions. Finally an experiment is implemented to test the efficiency of safety control architecture by using two robots to place some building blocks in the same workspace.
基金supported by the National Natural Science Foundation of China(No.6127249261572521)+1 种基金Natural Science Foundation of Shaanxi Provence(No.2013JM8012)Fundamental Research Project of CAPF(No.WJY201520)
文摘The trustworthiness of virtual machines is a big security issue in cloud computing. In this paper, we aimed at designing a practical trustworthiness mechanism in virtual environment. With the assist of a third certificate agent, the cloud user generates a trust base and extends it to its VMs. For each service running on the VM, a hash value is generated from all the necessary modules, and these hash values are organized and maintained with a specially designed hash tree whose root is extended from the user's trust base. Before the VM loads a service, the hash tree is verified from the coordinated hash value to check the trustworthiness of the service.
基金the Strategic research and consulting project of Chinese Academy of Engineering(2023-HY-14).
文摘Background Physical entity interactions in mixed reality(MR)environments aim to harness human capabilities in manipulating physical objects,thereby enhancing virtual environment(VEs)functionality.In MR,a common strategy is to use virtual agents as substitutes for physical entities,balancing interaction efficiency with environmental immersion.However,the impact of virtual agent size and form on interaction performance remains unclear.Methods Two experiments were conducted to explore how virtual agent size and form affect interaction performance,immersion,and preference in MR environments.The first experiment assessed five virtual agent sizes(25%,50%,75%,100%,and 125%of physical size).The second experiment tested four types of frames(no frame,consistent frame,half frame,and surrounding frame)across all agent sizes.Participants,utilizing a head mounted display,performed tasks involving moving cups,typing words,and using a mouse.They completed questionnaires assessing aspects such as the virtual environment effects,interaction effects,collision concerns,and preferences.Results Results from the first experiment revealed that agents matching physical object size produced the best overall performance.The second experiment demonstrated that consistent framing notably enhances interaction accuracy and speed but reduces immersion.To balance efficiency and immersion,frameless agents matching physical object sizes were deemed optimal.Conclusions Virtual agents matching physical entity sizes enhance user experience and interaction performance.Conversely,familiar frames from 2D interfaces detrimentally affect interaction and immersion in virtual spaces.This study provides valuable insights for the future development of MR systems.
基金Supported by collaborative project(ID3003)of the Vice-Rectors Office for University Outreach(VCM,Spanish acronym)of the Universidad San Sebastián Concepción,Republic of Chile.
文摘Background Fibromyalgia(FM)is a chronic rheumatic disorder characterised by musculoskeletal pain,fatigue,and psychoemotional symptoms.Virtual reality(VR)has proven to be an innovative and motivating tool for managing FM,with several studies indicating that it can improve quality of life indices and reduce psychoemotional symptoms.However,studies on immersive VR-based exercise(iVRE)are limited.Methods The aim of this study was to evaluate the effects of iVRE on quality of life,stress,anxiety,depression,and handgrip strength in patients with FM.A single-arm pre-post-test pilot study was conducted.Individuals diagnosed with FM were recruited using convenience sampling.The iVRE protocol consisted of 12 sessions of 10 min warm-up and 15 min exercises applied with the Oculus Quest 2TM device.The impact on quality of life was assessed using the Revised Fibromyalgia Impact Questionnaire,and the effects on stress,anxiety,and depression were determined using the Depression Anxiety Stress Scale-21 questionnaire.Handgrip strength was evaluated using the Baseline®dynamometer.The normality assumption was evaluated,and the pre-post means were compared using Student's ttest(p<0.05).Results Eleven individuals(40.6±11.2 years)completed the protocol(10 women).There were significant differences in favour of iVRE in quality of life impact(p<0.001,Cohen's d:1.48),handgrip strength(p<0.05,Cohen's d:0.26),depression(p<0.05,Cohen's d:0.73),and anxiety(p<0.05,Cohen's d:0.73).Conclusions A six-week iVRE program significantly reduces the impact on quality of life,anxiety,and depression and improves handgrip strength in people with FM.Future studies should investigate the physiological effects using systemic biomarkers to explain the scope of this therapeutic modality.
文摘Daylighting plays an eminent role in the performance of indoor environments and their occupants,thus necessitating the need to investigate daylight perception of potential occupants at early design stages.The present study introduces an interactive approach to collect and visualize brightness perception of daylighting in a large-scale immersive virtual environment using a game engine as a daylight simulation tool.The developed system allows users to explore building models freely at different day times set in virtual reality and report their perceptions in real time.Following a validation study(N=36)to investigate the consistency of brightness perceptions in a real environment and its virtual replica,a set of 24 participants were recruited to use the system to report their brightness perception in a virtual model of a daylit art museum,through snapshotting the scenes where they perceive as one of the following in terms of daylighting:(very dark,dark,bright,or very bright).Using an output of 419 snapshots,a"Perceptual Light Map"(PLM)was developed to visualize the collective brightness perception of participants as a heat map.Subjective responses were found to be positively correlated with four daylight metrics,with the highest correlation to mean luminance and the lowest to luminance ratio.The findings of this exploratory study represent a step towards a user-oriented supplement tool to the existing quantitative daylight metrics,validating game engines’adequacy as a daylight simulation tool,and illustrating the potentials of immersion and interaction principles for the perception of daylit spaces in virtual reality.
文摘Virtual reality(VR)is a frequently emphasized issue on the Digital Earth(DE)agenda.While current DE research is more engaged in the technical aspects of VR applications,this paper focuses on what is possible with immersive virtual environments(IVE)from the user’s perspective.After a brief discussion of spatial presence and embodiment in the context of IVE,both concepts will be merged into a geovisualization immersion pipeline(GIP)as a framework with which to systematically link technical and cognitive aspects of IVE.We will then analyze the general criteria that must be met by IVE in order to facilitate the experience of spatial presence.Adapting these criteria to the special requirements of geospatial data,a definition of geovisualization immersive virtual environments(GeoIVE)is formulated.Finally,the theoretical considerations of this paper are set into practice,using a GeoIVE of a coral reef ecosystem as an example.As we shall see,while GIS do not provide data models or data compatibility for direct visualization of GeoIVE on VR output devices,game engines can serve as middleware to fill this gap.
基金Research presented in this paper was funded by the National Key Research and Development Program of China[grant numbers 2016YFB0501503 and 2016YFB0501502]Hainan Provincial Department of Science and Technology[grant number ZDKJ2016021].
文摘An Augmented virtual environment(AVE)is concerned with the fusion of real-time video with 3D models or scenes so as to augment the virtual environment.In this paper,a new approach to establish an AVE with a wide field of view is proposed,including real-time video projection,multiple video texture fusion and 3D visualization of moving objects.A new diagonally weighted algorithm is proposed to smooth the apparent gaps within the overlapping area between the two adjacent videos.A visualization method for the location and trajectory of a moving virtual object is proposed to display the moving object and its trajectory in the 3D virtual environment.The experimental results showed that the proposed set of algorithms are able to fuse multiple real-time videos with 3D models efficiently,and the experiment runs a 3D scene containing two million triangles and six real-time videos at around 55 frames per second on a laptop with 1GB of graphics card memory.In addition,a realistic AVE with a wide field of view was created based on the Digital Earth Science Platform by fusing three videos with a complex indoor virtual scene,visualizing a moving object and drawing its trajectory in the real time.
