协同虚拟环境中分层智能化身控制模型的研究

为了增强协同虚拟环境中化身行为控制的智能性和模块独立性,基于VRML和智能代理技术设计和实现了一种分层智能化身控制模型.该模型中化身模拟智能实体的形体和简单行为,代理模拟智能实体的高级行为控制,化身代理和化身之间通过统一的调用接口进行控制和通信,使得模型各层之间有很好的模块独立性,并采用了基于规则的推理和分层有限自动机实现智能行为.最后的实例分析表明了该控制模型的可行性.     

分布式虚拟环境中区域重叠划分研究

分布式虚拟环境在划分区域后,区域边界附近的化身不能实时交换动态信息。针对这一情况,提出了区域重叠划分方法,通过增加一定的网络负载和多播组数目,来最大限度地保证相邻化身之间实时交换数据。详细分析了区域重叠划分方法,以及实现中的具体问题。     

基于Java和VRML的共享虚拟环境架构的研究

该文介绍了共享虚拟环境的概念和现状。提出了一种基于Java和VRML的共享虚拟环境的C/S架构。它使用通用的浏览器,具有很好的平台独立性和可扩展性。同时采用遵循H-Anim1.0人物建模标准来定义化身,具有好的通用性和可定制性。为了实现在Internet环境下的实时性,对传输某些经常变动的信息时在客户端采用了预测算法。实践证明,该系统在Internet环境下可以实现较好的效果。     

一种虚拟人漫游虚拟环境的路径规划算法

提出了虚拟人在3D障碍环境中进行漫游的路径规划算法，该算法以虚拟环境的表示为基础，首先，把虚拟环境离散化为3D单元格，用八叉树表示由此形成的环境图。然后，用启发式宽度优先搜索算法进行路径规划，产生从初始位置到目标位置的最优路径，引导虚拟人对环境进行漫游，算法的可行性和有效性经过了实验验证。     

虚拟制造中虚拟环境建模技术与方法

以虚拟制造烟基础的敏捷制造是一种全新的面向21世纪的制造系统，文 中探讨虚拟制造中虚拟环境的建立及其相关技术的研究与发展，涉及两个方面，虚拟环境的系统设计方法及计算模型。给出了描述虚拟环境的抽象框架，研究了基于网络的产品虚拟设计协作环境技术。     

基于集合论思想的协同虚拟环境交互研究

交互技术是协同虚拟环境中实现用户间的多感知（视觉、听觉、触觉等）交流与协作的重要手段。目前,在协同虚拟环境中,由于对存在的交互种类缺乏系统、全面的研究方法,从而用户交互程度明显不足,严重影响了地理协同工作。将集合论思想引入到协同虚拟环境的交互中,首次系统、完备性地分析了协同虚拟环境中存在的交互类型,将复杂的交互研究简化为6类交互的组合。在此基础上,采用Agent技术构建了智能语义物体模型以辅助交互的实现,并应用VTK和Cal3D软件开发包,实现了协同虚拟环境中基于化身的多种交互。     

智能虚拟环境中主体的情感计算研究

为了在智能虚拟环境中赋予主体情感能力,提高其逼真度及人机交互的自然性,并且兼顾虚拟环境的实时性要求,以心理学中的基本情绪理论和认知评价理论为依据,模拟推理规则为基础,提出了一种情绪产生器模型。该模型首先根据模糊IF-THEN规则制定情绪激发条件规则,进而推理得出“情绪因子”;然后建立了一个受情绪因子、个性及前一时刻的情绪状态制约的非线性函数,用来生成当前情绪及计算情绪强度。仿真结果表明,模型较符合人类的基本情绪状态的产生、迁移及衰减规律,在一定程度上体现了人类情绪的模糊性和非线性,而且易于机器实现。     

虚拟环境中物体物理特性的表示与处理

文中阐述了表示与处理虚拟物体和物理特性对虚拟环境逼真性重要意义，介绍了其研究内容，综述了当前的一些主要方法和关键技术，分析了目前存在的问题，并讨论了虚拟物体物理特性表示与处理的应用，最后展望了该研究领域的发展趋势。     

虚拟环境中行为建模技术研究

本文从软件方法学的角度将虚拟环境中行为建模技术分为基于过程的行为建模、基于对象的行为建模和基于Agent的行为建模，介绍这些技术的同时并分析了其各自的优缺点及适用范围，最后展望了行为建模技术的发展方向。     

教育合作虚拟环境中情感的表达

在合作虚拟环境中,应用具有情感表达面孔的虚拟替身有利于交流,通过实验对虚拟替身面部模型的有效性进行研究分析,结果表明,通过对模型适当的应用,情感能够通过一定数量的面部特征而被形象地表现出来。     

Real-Time Avatar Pose Transfer and Motion Generation Using Locally Encoded Laplacian Offsets

Journal of Computer Science and Technology - We propose a human avatar representation scheme based on intrinsic coordinates, which are invariant to isometry and insensitive to human pose changes,...     

基于Maya脚本语言的虚拟士兵动画研究

在三维动画制作软件中,传统的人工调整虚拟人动作的工作方式已经不再适合现在的计算机动画制作。针对这一问题,提出了一种采用Maya脚本语言编程来实现人物动画控制的用户界面,在该界面中,动画师可以通过选择按钮移动滑块进行关键帧的设置,从而产生骨架的运动,形成动画。该方法可以提供对制作人物特征有用的工具,使得人物动画的制作更简单。     

立体摄像系统及其在真实感头部化身生成中的应用

提出了一种新的真实感头部化身生成技术,该技术利用立体摄像机产生的二维图片和深度图生成化身脸部,而用三维模型和贴图生成化身其他部位,从而实现用有限的硬件和运算量得到较真实的头部化身。     

Design and display of enhancing information in desktop information-rich virtual environments: challenges and techniques

Information-rich virtual environments (IRVEs) have been described as environments in which perceptual information is enhanced with abstract (or symbolic) information, such as text, numbers, images, audio, video, or hyperlinked resources. Desktop virtual environment (VE) applications present similar information design and layout challenges as immersive VEs, but, in addition, they may also be integrated with external windows or frames commonly used in desktop interfaces. This paper enumerates design approaches for the display of enhancing information both internal and external to the virtual worlds render volume. Using standard Web-based software frameworks, we explore a number of implicit and explicit spatial layout methods for the display and linking of abstract information, especially text. Within the VE view, we demonstrate both heads-up-displays (HUDs) and encapsulated scenegraph behaviors we call semantic objects. For desktop displays, which support information display venues external to the scene, we demonstrate the linking and integration of the scene with Web browsers and external visualization applications. Finally, we describe the application of these techniques in the PathSim visualizer, an IRVE interface for the biomedical domain. These design techniques are relevant to instructional and informative interfaces for a wide variety of VE applications.     

Avatar gender and personal space invasion anxiety level in desktop collaborative virtual environments

We report an investigation exploring the effect of avatar gender on the anxiety level caused by personal space (PS) invasion in desktop collaborative virtual environments (DCVE). We outline an experiment in which participants, of both genders, whose avatars PS were invaded by other avatars of either gender, reported their anxiety levels through the use of a post-experiment questionnaire. The data from the questionnaire are analysed and discussed. The results suggest that the combination of the gender of the invading avatar and the avatar being invaded has an influence on the PS invasion anxiety level and that the ranking of gender combination groups has a striking difference from those observed for PS invasion in physical environments. Results also show that the participants in general did not register high anxiety, contrary to what one might expect from personal space invasion in the physical world.

Cross‐platform management of intelligent objects behaviors in serious virtual environments

In this paper, we present a generic interaction framework that controls intelligent objects' actions in different virtual world (VW) platforms. These actions are based on the state of external platform‐independent artificial intelligence‐based systems such as multi‐agent and rule‐based systems. We have evaluated the proposed framework by means of two intelligent objects, a door and a noticeboard, incorporating them in Second Life and OpenWonderland VWs. These objects allow to work along three advanced aspects of a serious virtual environment: it is a dynamic space where participants are synchronously informed about activities evolution inside the virtual space, it can integrate processes and information coming from the real world, and it needs norms to organize participants actions, to define actions consequences, and to prevent undesired participants behaviors. Copyright © 2011 John Wiley & Sons, Ltd.     

Recent advances on virtual human synthesis

Virtual human is a digital representation of the geometric and behavioral property of human beings in the virtual environment generated by computer. The research goal of virtual human synthesis is to generate realistic human bodymodels and natural human motion behavior. This paper introduces the development of the related researches on these two topics, and some progresses on example based human modeling and motion synthesis, and their applications in Chinese sign language teaching, computeraided sports training and public safety problem studying. Finally, some hot research topics in virtual human synthesis are presented. Supported partially by the National High-Tech Research & Development Program of China (Grant Nos. 2006AA01Z336, 2007AA01Z320), and the National Natural Science Foundation of China (Grant No. 60533070)     

Virtual interpersonal touch: Haptic interaction and copresence in collaborative virtual environments

As digital communication becomes more commonplace and sensory rich, understanding the manner in which people interact with one another is crucial. In the current study, we examined the manners in which people touch digital representations of people, and compared those behaviors to the manner in which they touch digital representations of nonhuman objects. Results demonstrated that people used less force when touching people than other nonhuman objects, and that people touched the face with less force than the torso area. Finally, male digital representations were touched with more force than female representations by subjects of both genders. We discuss the implications of these data to the development of haptic communication systems as well as for a methodology of measuring the amount of copresence in virtual environments.

Presence: a unique characteristic in educational virtual environments

This article investigates the effect of presence on learning outcomes in educational virtual environments (EVEs) in a sample of 60 pupils aged between 11 and 13 years. We study the effect of personal presence, social presence and participant’s involvement on certain learning outcomes. We also investigate if the combination of the participant’s representation model in the virtual environment (VE) with the way it is presented gives a higher sense of presence that contributes to learning outcomes. Our results show that the existence of an avatar as the pupils’ representation enhanced presence and helped them to successfully perform their learning tasks. The pupils had a high sense of presence for both cases of the EVE presentation, projection on a wall and through a head mounted display (HMD). Our socialized virtual environment seems to play an important role in learning outcomes. The pupils had a higher sense of presence and completed their learning tasks more easily and successfully in the case of their egocentric representation model using the HMD.