基于虚拟现实技术的影视后期制作软件开发研究

随着科学技术的不断发展,影视后期制作融入了虚拟现实技术。文章研究了虚拟现实技术在影视后期制作中的开发与探索,并进行了相关实验,阐述了虚拟现实技术在影视场景设计中的应用。     

基于矢量传感器的空中脱靶量测量方法研究

针对现有声学空中脱靶量测量方法,无法实现三维定位的现状,提出引入矢量传感器技术的新思路.设计了一种基于矢量声学传感器的布阵方案,采用声压、振速互谱实现了目标的到达方向(DOA)估计,并利用概率法实现了多基阵的目标三维定位.通过仿真实验表明:该方法可以解决声学脱靶量测量空间定位技术难题,定位精度满足要求.     

复合材料结构水下振动噪声仿真研究

开展复合材料夹芯板的损耗特性测试试验,获得了复合材料夹芯板结构内损耗因子,并以此作为数值计算的基础参数输入;采用声固耦合有限元分析法,对水下航行器上层建筑采用复合材料夹芯板后的振动声辐射特性进行分析;探索了壳板厚度参数对水下航行器上层建筑振动声辐射特性的影响规律,提出了复合材料上层建筑结构声学优化设计方案,旨在为上层建筑结构声学设计提供参考.     

虚拟现实技术及建筑设计方案优化

虚拟现实是计算机领域的一门新兴技术.虚拟现实技术是一项综合性建筑设计方法,能够减轻设计人员的劳动强度、缩短设计周期、提高设计质量、节省投资.本文首先介绍了虚拟现实技术的基本概念,重点阐述了虚拟现实技术在建筑设计方案优化中的重要作用,旨在为建筑方案的优化设计提供依据.     

基于分布式Vega的多通道投影视景仿真方法

针对多通道投影视景仿真通道问帧不同步,以及视点、角色对象位姿不一致的问题,研究基于分布式vega数据插播技术的多通道投影视景仿真方法,解决通道间帧同步和视点一致性问题.实验表明该方法对于多通道投影视景仿真开发具有简单方便,通道间帧同步性能好,视点、角色对象位姿完全一致的特点.     

虚拟现实技术在城市规划中的应用探究

在我国城市化迅速发展与扩张的形势下,运用传统二维GIS数据技术、图纸设计等进行城市规划,已不能满足城市设计与规划的要求.而基于3D模型的虚拟现实技术,可以在虚拟空间中完成对城市的立体化模拟,以构建出更加真实的城市网络架构.文章主要探讨虚拟现实技术在城市规划中的应用,通过分析虚拟现实技术与城市仿真等,提出虚拟现实技术在城市规划中的应用方案.     

基于矢量传感器的空中脱靶量测量方法研究

针对现有声学空中脱靶量测量方法,无法实现三维定位的现状,提出引入矢量传感器技术的新思路。设计了一种基于矢量声学传感器的布阵方案,采用声压、振速互谱实现了目标的到达方向﹙DOA﹚估计,并利用概率法实现了多基阵的目标三维定位。通过仿真实验表明:该方法可以解决声学脱靶量测量空间定位技术难题,定位精度满足要求。     

基于VRML模型和ASP技术虚拟漫游展厅构建的研究

针对民族体育数字化保护和展示宣教的需要,根据虚拟现实中两种不同虚拟漫游方式:实景漫游和虚拟漫游,探讨了实现这两种方式的关键技术.结合新疆民族体育虚拟展厅的具体实践,设计完成了实景和虚景的构造过程.     

高速气流环境下的管道声衬阻抗模型研究

微穿孔板声衬基于亥姆霍兹共振器原理,是一种用于控制高速气流环境下管道噪声的非常有效的手段,其一般有单层、双层甚至多层的结构形式.当前,微穿孔板声衬在无气流环境下的声学设计理论成熟可靠,但在有气流,特别是在高速气流环境下的设计过程复杂,影响因素多,尚未形成成熟统一的设计理论依据.文章基于无气流环境下的声学设计理论,在单层...     

蒸汽发生器干燥器声疲劳行波管模型仿真分析

随着核电企业采用提升功率的方式提高发电效益,其内部的干燥器容易受到较高的脉动压力载荷而导致声疲劳.介绍蒸汽发生器干燥器声疲劳试验方案——行波管混响腔模型.利用计算声学软件Actran进行仿真分析,研究试验装置内部声载荷分布特征.研究结果为后续试验研究提供技术支撑.     

The Internet Chair

A pivot (swivel, rotating) chair is considered as an input/output device, an information appliance. The input modality is orientation tracking, which can dynamically select transfer functions used to spatialize audio in a rotation-invariant soundscape. In groupware situations, like teleconferencing or chat spaces, such orientation tracking can also be used to twist iconic representations of a seated user, avatars in a virtual world, enabling social situation awareness via coupled visual displays, soundscape-stabilized virtual source locations, and direction-dependent projection of non-omnidirectional sources. Using its audio output modality, the system can present unencumbered binaural sound with soundscape stabilization for multichannel sound image localization.     

Sound production and modeling

Sound in multimedia, movies, games, virtual reality, and human-computer interfaces is a growing field that encompasses the disciplines of analog and digital signal processing, physics, speech, music, perception, and computer systems architecture. This overview of sound production and modeling techniques surveys the state of the art in sound technology. Sound has become a critical component in modern multimedia systems, especially multispeaker surround-sound entertainment systems. Many of the components and techniques in these systems are also applicable in virtual and augmented reality systems. With basic sound hardware now available for most (but not all, as in some palmtops) computer systems, and increasing processor speeds allowing direct real-time sound manipulation, enhancing multimodal computer-human interfaces by using the sonic channel is becoming commonplace. Sound in games and other graphics-intensive real-time applications is achieving higher levels of sophistication and promises to undergo even further advancements in realism and responsiveness.     

Film and television industry cloud exhibition design based on 3D imaging and virtual reality

The three-dimensional virtual scene can provide users with a visual three-dimensional virtual environment, with various multimedia channels such as sound, video, force feedback equipment, etc., to bring users a completely immersive interactive experience. This paper introduces 3D imaging and virtual reality technology in the film and television industry cloud exhibition, and develops a virtual display platform. First of all, this paper divides the registration into two processes: camera calibration and joint calibration of the camera and laser scanner based on the calibration results. Camera calibration can determine the plane model of the calibration board in the camera coordinate system, and the joint calibration uses the RANSAC algorithm to extract the point cloud of the plane model of the calibration board, and then optimizes the distance between the points in the plane model point cloud and the corresponding plane in the camera coordinate system Find the optimal transformation between the two sets of data, and then calculate the registration relationship between the point cloud and the image. Secondly, this article conducts a demand analysis of the film and television industry cloud exhibition platform based on virtual reality technology, including the business goals set by the platform, platform system analysis, overall design, and system operating environment and configuration requirements. This model provides a feasible solution for the visual interaction of the cloud exhibition design of the film and television industry.     

Effects of frame rate on vection and postural sway

The quality of stereoscopic 3D cinematic content is a major determinant for user experience in immersive cinema in both traditional theatres and cinematic virtual reality. One of the most important parameters is the frame rate of the content which has historically been 24 frames per second for movies, but higher frame rates are being considered for cinema and are standard for virtual reality. A typical behavioural response to immersive stereoscopic 3D content is vection, the visually-induced perception of self-motion elicited by moving scenes. In this work we investigated how participants’ vection varied with simulated virtual camera speed, frame rate, and motion blur produced by the virtual camera’s exposure, while viewing depictions of movement through a realistic virtual environment. We also investigated how their postural sway varied with these parameters and how sway covaried with levels of perceived self-motion. Results show that while average perceived vection significantly increased with 3D content frame rate and motion speed, motion blur had no significant effect on perceived vection. We also found that levels of postural sway induced by vection correlated positively with subjective ratings.     

基于学习风格的自适应式虚拟交互方法的研究

新工科教育的改革推进了自适应学习的发展,以往的自适应方式对学习者的主观能动性的重视不足,且大部分已有研究无法提供个性化程度较高的交互体验.针对这些问题,该研究基于学习风格模型提出了一种自适应式虚拟现实交互的新方法.该方法设计了适用于虚拟交互环境的学习风格判断方式,通过分析学习者的主客观数据来判断其学习风格,由此对交互环...     

Auditory and visual 3D virtual reality therapy for chronic subjective tinnitus: theoretical framework

It is estimated that ~10% of the adult population in developed countries is affected by subjective tinnitus. Physiopathology of subjective tinnitus remains incompletely explained. Nevertheless, subjective tinnitus is thought to result from hyperactivity and neuroplastic reorganization of cortical and subcortical networks following acoustic deafferentation induced by cochlear or auditory nerve damage. Involvement of both auditory and non-auditory central nervous pathways explains the conscious perception of tinnitus and also the potentially incapacitating discomfort experienced by some patients (sound hypersensitivity, sleep disorders, attention deficit, anxiety or depression). These clinical patterns are similar to those observed in chronic pain following amputation where conditioning techniques using virtual reality have been shown both to be theoretically interesting and effectively useful. This analogy led us to develop an innovative setup with dedicated auditory and visual 3D virtual reality environments in which unilateral subjective tinnitus sufferers are given the possibility to voluntarily manipulate an auditory and visual image of their tinnitus (tinnitus avatar). By doing so, the patients will be able to transfer their subjective auditory perception to the tinnitus avatar and to gain agency on this multimodal virtual percept they hear, see and spatially control. Repeated sessions of such virtual reality immersions are then supposed to contribute to tinnitus treatment by promoting cerebral plasticity. This paper describes the theoretical framework and setup adjustments required by this very first attempt to adapt virtual reality techniques to subjective tinnitus treatment. Therapeutic usefulness will be validated by a further controlled clinical trial.     

增强现实系统中的虚拟交互方法

在基于ARToolKit的增强现实系统中,注册在不同标识物上的三维虚拟物体因交互行为而发生碰撞时,虚实融合会失真。为解决该问题,提出一种能增加虚拟交互功能的碰撞反应算法。根据检测到的碰撞信息,实时调整虚拟物体碰撞后相对于标识物的位置和姿态,消除物体穿透现象,保持虚实融合场景的真实感。实验结果表明,该虚拟交互方法能获得比较自然和真实的交互性体验。     

Establishing the Usability of a Virtual Training System for Assembly Operations within the Automotive Industry

Virtual training systems deliver training within a virtual environment (VE) using virtual reality (VR) or augmented reality (AR) technologies. However, to be fully accepted as a valid tool for training within the automotive industry, evidence is required on the ability of these systems to deliver effective and efficient training to the relevant users. This paper aims to investigate the effectiveness and efficiency of the first prototype of the virtual training system (VTS) developed within the VISTRA (Virtual Simulation and Training of Assembly and Service Processes in Digital Factories) project (FP7‐ICT‐285176), using real end users from the OPEL automotive plant in Rüsselsheim, Germany. Two separate and independent studies were employed that used objective and subjective methods of investigation to establish performance and usability measures. The objective results show that virtual training was effective in reducing error during task performance when compared to traditional training. The subjective results concluded that the opinions of the participants were mainly positive concerning the overall use of the VTS for assembly operation training; however, a number of issues were highlighted and reported to the developers for further advancement of the system.     

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.     

The Role of 3-D Sound in Human Reaction and Performance in Augmented Reality Environments

Three-dimensional sound's effectiveness in virtual reality (VR) environments has been widely studied. However, due to the big differences between VR and augmented reality (AR) systems in registration, calibration, perceptual difference of immersiveness, navigation, and localization, it is important to develop new approaches to seamlessly register virtual 3-D sound in AR environments and conduct studies on 3-D sound's effectiveness in AR context. In this paper, we design two experimental AR environments to study the effectiveness of 3-D sound both quantitatively and qualitatively. Two different tracking methods are applied to retrieve the 3-D position of virtual sound sources in each experiment. We examine the impacts of 3-D sound on improving depth perception and shortening task completion time. We also investigate its impacts on immersive and realistic perception, different spatial objects identification, and subjective feeling of "human presence and collaboration". Our studies show that applying 3-D sound is an effective way to complement visual AR environments. It helps depth perception and task performance, and facilitates collaborations between users. Moreover, it enables a more realistic environment and more immersive feeling of being inside the AR environment by both visual and auditory means. In order to make full use of the intensity cues provided by 3-D sound, a process to scale the intensity difference of 3-D sound at different depths is designed to cater small AR environments. The user study results show that the scaled 3-D sound significantly increases the accuracy of depth judgments and shortens the searching task completion time. This method provides a necessary foundation for implementing 3-D sound in small AR environments. Our user study results also show that this process does not degrade the intuitiveness and realism of an augmented audio reality environment