基于骨骼的三维虚拟人运动合成方法研究

针对虚拟人运动合成中建立的人体模型存在复杂化、合成的虚拟人运动序列逼真度差的问题,提出了一种基于骨骼的虚拟人运动合成方法。在分析人体结构的基础上,通过三维图形软件获取人体骨骼数据,构建虚拟人体的骨骼模型。另外,将关键帧四元数球面插值算法与时间和空间变形方法相结合,生成多样化的虚拟人运动序列。实验结果验证了该方法的有效性。     

基于国标人体测量学数据的虚拟人缩放方法

具有准确人体测量学数据的虚拟人模型在虚拟制造和虚拟维修领域有重要的理论和现实意义。此外,根据某些人体测量学数据,参照典型的人体模型生成特定的虚拟人,即实现人体模型的参数化控制,对于合理地进行人机功效分析也有重要的应用价值。该文在分析我国成年人体测量学数据标准的基础上,通过研究Jack软件中人体模型表示方法和人体测量学数据之间的映射关系,提出了一种基于人体测量学数据的人体模型动态缩放方法。利用该方法在Jack软件中建立了基于国标人体测量学数据的人体模型动态缩放子系统。     

基于OPENGL的人体姿态数据仿真

依据人体的关节连接体层次结构,将各肢体抽象为简单的刚性几何实体,构建了人体骨骼模型,通过定义人体坐标和肢体局部坐标及其相互间的变换,描述了人体骨骼模型中各关节之间的相对位置和姿态的变化.详细论述了应用D-H方法分析人体上肢运动模型的方法,最后利用VC++构建了基于OpenGL技术的虚拟人体运动程序.该应用程序可以在虚拟环境中载入、驱动并显示一个三维虚拟人.它能够灵活的利用采集得到人体运动数据驱动虚拟人,可以应用于医学仿真、智能人机交互等领域.     

基于Poser模型的三维人体建模方法

人体真实感建模是虚拟人研究领域的一项重要内容。该文提出一种基于模型的快速人体建模方法。人体几何模型的皮肤层由多边形网格组成的表面表示,骨架层建模采用H-Anim标准,并针对Poser软件输出的人体模型缺乏关节点数据问题,给出一种骨架提取算法。人体运动模型应用机器人运动学方法,由骨架层驱动皮肤层实现。在VC++平台上实现对不同姿势下人体模型的骨架提取,仿真了敬礼过程中手臂的运动,验证了该方法的可行性。     

基于轴变形技术的实时人体肌肉变形

1引言 真实感虚拟人的建模是计算机图形学领域中最具挑战性的工作之一.自七十年代以来,人体建模的计算模型出现了包括从杆状模型、简单的多边形模型到曲面模型甚至有限元模型,生成的3D人物在虚拟现实系统、视频游戏、电影和电视广告中得到了广泛的应用.虽然研究人员在表示和变形虚拟人体形状已取得了很大进展,但人体的逼真动画还没有取得较为满意的结果,其中一个最主要的挑战在于:人体运动时皮肤的自动与真实的变形.对于逼真人体的实时变形模拟,国内外的研究相对较少,随着计算机硬件的飞速发展,虚拟社区、虚拟战场等实时分布式虚拟现实技术的应用需求的不断增加,需要虚拟人不仅具有非常强的真实感,而且能够实时地做出各种动作和姿态.这就为虚拟人建模提出了更高的要求.     

基于球B样条的3D人物角色建模与动画

提出一种新的人物角色的快速建模和动画的方法.通过使用球B样条实现以骨架为基础自动构建角色模型以及数据驱动的角色动画生成方法.给定人物角色骨架后,依据人体测量学根据骨骼长度计算出关节点处的半径.通过插值关节点以及半径生成球B样条曲线曲面表示的角色模型.根据所获取的运动数据(来自运动捕获),通过更新控制顶点来更新角色模型,从而实现角色的实时动画.     

运动状态下虚拟人全身皮肤实时变形方法

完善了已有的广义交叉截面法,针对人体全身各处的特点提出了多种灵活有效的截面分组方法,实现了人体运动状态下的全身皮肤实时变形;同时结合插值方法,进一步提高肩关节、髋关节等运动幅度较大部位的皮肤变形效果.该方法适用于任意皮肤网格组织方式的虚拟人模型,能够在人体各种运动状态下实时生成逼真的全身皮肤运动变形.     

基于微型传感器驱动的三维实时运动人体模型

建立一种运用于人体运动捕获与再现系统的人体模型,实现人体运动实时控制模型的运动.根据微型传感器人体运动捕获与再现系统的特点,提出一种三维人体模型的层次化结构建模方法和多边形分组皮肤变形方法.该方法以生物动力学为基础,根据人体关节的运动特征进行分层表示,采用传感器数据驱动并控制人体骨架模型的运动以及皮肤模型的变形,实时再现真实人体运动.实验表明,新建模方法适用于传感器数据驱动人体模型的实时运动再现,并能够逼真地体现人体运动的生物力学特征.     

一种具有逼真效果的虚拟人动画生成方法

针对传统的虚拟人动画逼真度低、动画生成复杂、且动画存在飘移现象的问题,提出了一种基于视频关键帧获取运动数据的虚拟人动画生成方法。首先利用线性混合蒙皮算法建立了新的人体几何模型;其次利用正向运动学方法驱动虚拟人的骨骼模型,并利用平移补偿原则消除虚拟人运动中的飘移现象;最终实现了基于双目正交视觉获取关节运动参数的虚拟人动画。实验结果表明,新方法能逼真地模拟真实人体动作,且方法易于实现、实用性强。     

基于OSG的人体手臂姿态数据仿真

为了实现由加速度传感器准确感知人体手臂运动姿态的目的,本文依据人体的关节连接体层次结构,将各肢体抽象为简单的刚性几何体,构建了人体骨骼模型,并为骨骼模型建立了美观的皮肤。通过AVR单片机采集绑定在人体手臂上的加速度传感器的模拟数据进行A/D转换,从而感知人体手臂姿态的变化,再通过NRF905无线传输模块将数据传送至PC机,最后在Visual Studio2005环境下构建了基于OSG技术的虚拟人体运动仿真程序,实现了由人体手臂动作驱动三维虚拟人进行相同动作的功能。     

手部运动计算机仿真的实现

根据手部自身的物理特性和生理特性,采用分层技术,严格按照手部解剖学,先建立其骨骼模型,在此基础上形成肌肉模型,最后在肌肉模型上附加一层皮肤。这样,骨骼运动引起肌肉的变形,随着皮肤也跟着发生相应的变化,使虚拟手模型无论从形状上还是运动上都能达到更高程度的逼真效果。     

The effect of tendons on foot skin deformation

Anatomical human models are usually divided into layers including skin, muscle and skeleton. In spite of the realistic animation of the models that can be achieved, and the realistic appearance of the model determined by the underlying muscles and skeleton, the role of tendons in determining the deformation of skin surface has not been well addressed.This paper presents an approach for modeling human foot tendons and determines their influence on the skin layer deformation. Our goal is to model deformation of the tendons such that a realistic foot simulation can be obtained. An anatomical foot model including skin, muscle, tendon and skeleton layers is adopted. The appearance of the skin layer is determined based on the underlying layers. To allow interactive deformation of the tendon models, the axial deformation technique is adopted. Given the position of the foot and the basis function, the position of the data points that control the axial curve is updated. To allow more accurate computation of the data point positions, a method that estimates the basis function based on real data obtained from foot images is also presented. Experimental results showed that the axial deformation technique can model deformation of the foot tendons with satisfactory visual realism. With the tendon deformation, the visual realism on the skin deformation is also enhanced.     

Skeleton-aware size variations in digital mannequins

The general trend in character modeling is toward the personalization of models with higher levels of visual realism. This becomes possible with the development of commodity computation resources that are capable of processing massive data in parallel across multiple processors. On the other hand, there is always a trade-off between the quantity of the model features that are simulated and the plausibility of the visual realism because of the limited computation resources. Also, to keep the resources’ to be used efficiently within the other modeling approaches such as skin reflectance, aging, animation, etc., one must consider the efficiency of the method being used in the simulation. In this paper, we present an efficient method to customize the size of a human body model to personalize it with industry standard parameters. One of the major contributions of this method is that it is possible to generate a range of different size body models by using anthropometry surveys. This process is not limited by data-driven mesh deformation but also adapts the skeleton and motion to keep the consistency between different body layers.     

Layered rhombus-chain-connected model for real-time haptic rendering

The modeling and simulation of deformable objects is a challenging topic in the field of haptic rendering between human and virtual environment. In this paper, a novel and efficient layered rhombus-chain-connected haptic deformation model based on physics is proposed for an excellent haptic rendering. During the modeling, the accumulation of relative displacements in each chain structure unit in each layer is equal to the deformation on the virtual object surface, and the resultant force of corresponding springs is equivalent to the external force. The layered rhombus-chain-connected model is convenient and fast to calculate, and can satisfy real-time requirement due to its simplicity. Experimental study in both homogenous and non-homogenous virtual human liver and lungs based on the proposed model are conducted, and the results demonstrate that our model provides stable and realistic haptic feeling in real time. Meanwhile, the display result is vivid.     

一种基于人体测量学的三维人体快速建模方法研究与实现

常用的个性化三维人体建模方法存在数据量大,处理过程复杂,不适合Web应用的不足,该文提出一种新的快速进行三维人体建模的方法,该方法根据人体测量学和人体解剖学原理,结合人体表面特征点和特征线分布规律,应用超椭圆仿真人体各截面、采用层次参数驱动设计思想,实现快速创建个性化三维人体模型。该方法具有满足实时要求、交互参数少,易于控制,误差小、模型真实感强等优点,并可以准确地提供骨骼关节点和人体特征点．适于三维仿真形象动态设计、人体运动模拟和虚拟服装试衣等多种应用。     

一种基于传感器的人体上肢运动实时跟踪方法

实时跟踪人体运动是人机交互的重要研究课题,可以广泛应用于虚拟现实、虚拟人运动合成、聋人手语自动生成、计算机3D动画、机器人运动控制、远程人机交互等领域。文中介绍了一种基于传感器的人体上肢运动实时跟踪方法,给出了该方法的虚拟人模型、计算原理与校正方法,最后介绍了整个方法的实现以及在中国聋人手语自动合成中的应用。该方法具有使用传感器少,运动跟踪精度高、计算过程简单而且速度快等特点。     

Pose space parameterization and style transfer of skin deformation

We present a technique to parameterize skin deformation by skeletal motion and to transfer the deformation style from one character to another. We decompose skin deformation into time‐varying signals and basis matrices by using dimension reduction techniques and then approximate the time‐varying signals by using radial basis functions with respect to joint angles that define skeletal motion. This decomposition reduces the size of deformation data to a small number of time‐varying signals that represent the complex role of muscle action. The subsequent parameterization yields a fast and intuitive control of characters; thus, it allows us to construct faithful skin deformations quickly as skeletal bones move. The representation of our parameterization allows us to capture and transfer a derived deformation style to another skeleton–skin structure without considering the input dimension of the deformation data. This style transfer can be used as a basis for realistically animating variants of sample characters that have the same skeletal topology. Parameterization of skin deformation and its style transfer can be performed within a small amount of error once the preprocessing time and control of the deformation is carried out in real time by our graphics processing unit implementation. Copyright © 2011 John Wiley & Sons, Ltd.