基于Java3D的虚拟环境中智能体视觉传感器设计

提出用Java3D实现虚拟视觉传感器的技术,设计出一个虚拟相机类VirtualCamera,它所表示的虚拟视觉传感器可安装在用Java3D所创建的虚拟环境中的任意物体上.将该虚拟相机类生成的视觉传感器装到作者用Java3D研制的驾驶仿真系统中的环境车辆上进行了验证.结果表明各环境车能按机器视觉方式采集道路环境的图像,为环境车辆按计算机视觉原理认知道路环境并进行行驶控制奠定了基础,进而可使驾驶仿真系统能用于对物理智能车辆对道路环境的感知与行驶决策进行仿真、设计与评价.     

网络环境下基于立体视觉和数据手套的模具虚拟装配

以Java／Java3D为工具，开发了一个基于Web的半沉浸式模具虚拟装配环境，实现了系统的立体显示功能，解决了虚拟手操作中的广义碰撞检测问题。提供了虚拟场景中生成和管理装配路径的方法，可应用于装配评价和装配规划。系统采用B／S模式，充分发挥Web3D的优势，以多通道的交互式平台支持模具的协同设计，有助于提高模具设计效率。     

基于Java 3D技术的虚拟车辆仿真系统

虚拟车辆仿真是智能交通研究中的重要课题,而运用Java3D技术构建该系统则是一个崭新的研究方向。该文详细地阐述了Java3D技术在虚拟车辆仿真系统中的运用,就具体的设计和所涉及的技术问题进行了系统、深入的分析,并提出新的解决办法。最后,对该领域的技术前景进行了展望。     

Java 3D在数控仿真中的运用

文章对网络图形建模语言(Java 3D)进行了研究,通过Java 3D构建三维世界,并在网页上显示三维图像,用Java 3D的图形技术,把转换形成的图形格式直接用于仿真之中,不需要利用编程方式进行建模。使得数控加工仿真技术达到缩短加工编程的周期、提高生产效率、降低生产成本的意义。     

运用Java 3D体系结构实现虚拟对象控制

基于Web酊Java 3D图形技术提供了一种创建自主虚拟现实代理的工具，它广泛的应用于教育、娱乐和仿真系统。本文讨论了使用Java 3D控制体系结构实现虚拟对象控制，以及使用虚拟现实开发环境构建3D平台所遇到的某些问题，通过虚拟对象控制机制成功地实现一系列虚拟空间行为动作。     

面向VR应用系统的Java 3D API

0　引　言Java3D API是用来开发三维图形和开发基于Web的 3D应用程序 (applet)的编程接口 .目前用于开发三维图形软件的 3D API(Open GL、Direct3D)都是基于摄像机模型的思想 ,即通过调整摄像机的参数来控制场景中的显示对象 ,而 Java3D则提出了一种新的基于视平台的视模型和输入设备模型的技术实现方案 ,即通过改变视平台的位置、方向来浏览整个虚拟场景 .它不仅提供了建造和操作三维几何物体的高层构造函数 ,而且利用这些构造函数还可以建造复杂程度各异的虚拟场景 ,这些虚拟场景大到宇宙天体 ,小到微观粒子 .Java 3D 是Java Med…     

遥操作正骨机器人虚拟手术仿真系统研究

分析了将虚拟现实技术引入医疗机器人系统的重要性，结合本实验室研制的医疗正骨机器人系统提出了一种基于Java3D、视觉反馈和力反馈的遥操作正骨机器人虚拟手术仿真系统．文章介绍了系统的总体结构、工作原理和软、硬件平台，分析了虚拟和现实两个子系统的工作流程，并描述了系统内各主要模块的功能．     

基于Creator/Vega的虚拟场景设计与实现

阐述了基于Creator/Vega的虚拟场景仿真系统的设计过程.结合虚拟场景系统开发实例,从视景建模角度,详细分析了纹理贴图得几何尺寸和模型多边形数量,对系统运行性能的影响,并提出了利用纹理贴图、LOD和网格等建模技术提高系统运行性能的方法.在虚拟场景驱动中,实现了利用键盘、鼠标等一般输入输出设备,进行步行、鸟瞰等多种方式的漫游,增进了人机交互性能.为使系统支持立体显示,运用了Vega提供的立体显示技术.文中涉及的技术对其它虚拟场景仿真系统的开发具有重要参考价值.     

基于虚拟现实技术的车床仿真系统

基于开发CA6132型车床虚拟教学软件的目的,采用了虚拟仿真的方法,开发了带有虚拟现实特征的车床教学系统软件.提出了虚拟车床开发的一般流程,阐述了矫正图像的立面分割技术,开发了基于Unity3D引擎软件的虚拟车床仿真系统,解释了虚拟现实的基本原理,建立了CA6132型车床的三维模型,提出了在Unity3D下车床加工的仿真方法,开发了基于虚拟现实设备zSpace虚拟现实车床仿真系统,提出了虚拟现实的场景交互方式,降低了实际车床操作的危险.     

基于Direct3D的虚拟驾驶系统的智能体的实现

介绍DirectX的组件Direct3D,以DirectX为接口开发虚拟驾驶系统,应用Direct3D技术实现了驾驶模拟视景系统中智能体的运动仿真、智能体三维模型在虚拟场景中的显示变换,应用面向对象技术创建基于Direct3D的车辆智能体类库,应用这些类库在虚拟环境中实现汽车的虚拟驾驶模型。     

Tutorial: time-multiplexed stereoscopic computer graphics

Time-multiplexed stereoscopic systems, which present the stereoscopic image by alternating right- and left-eye views of a scene on a CRT, are considered. The current technology for stereoscopic computer graphics is introduced, and an overview of factors important to the proper construction and display of computer images in a time-multiplexed environment is provided. The discussion covers the computation of stereoscopic views, stereoscopic display algorithms, horizontal parallax and factors affecting image quality     

Human fusion range for polarized 3D display

If discrepancy between accommodation and convergence caused by a stereoscopic display exceeds fusion range of human eyes, viewers will see ghosting image, which leads to the loss of correct depth information and even causes severe visual fatigue. In this paper, an experiment aiming to investigate the binocular fusion range is conducted for a polarized 3D display. Two experimental trials are arranged to examine two aspects of fusion range including outward depth and inward depth. 3D modeling software is used to generate the test stereoscopic image pairs, which vary in depth by adjusting the separation between the virtual cameras. Angular parallax corresponding to the limit of fusion range is obtained by determining critical point of ghosting images. The experimental results show deviation between theoretical fusion range calculated by formula and experimental one.?0.223° to 0.275° represent critical fusion range for the polarized 3D display to avoid ghosting images.     

Quantitative assessment of the effectiveness of using display techniques with a haptic device for manipulating 3D objects in virtual environments

Quantitative assessment is made of using two display techniques, providing two different levels of depth perception, in conjunction with a haptic device for manipulating 3D objects in virtual environments. The two display techniques are 2D display, and interactive 3D stereoscopic virtual holography display on a zSpace tablet. Experiments were conducted, by several users of different ages and computer training. The experiments involved selected pointing and manipulation tasks. The speed of performing the tasks using the two display techniques were recorded. Statistical analysis of the data is presented. As expected, the use of interactive 3D stereoscopic display resulted in faster performance of the tasks. The improvement in performance was particularly noticeable for the cases wherein the subjects needed to manipulate the haptic arm to reach objects/targets at different depths, and also when the objects/targets were occluded partially by the obstacles.     

基于Java 3D的虚拟人仿真方法

提出一种将3DS MAX、MS3D与Java 3D编程技术相结合的虚拟人仿真方法,可使虚拟人达到相对逼真且交互性强的效果。该方法首先采用3DS MAX角色动画技术进行人体静态建模和动作建模;然后通过将底层基本动作片段转化为MS3D格式,供Java 3D的骨骼动画模型接口调用;最后利用Java 3D编程来控制虚拟人的高层行为活动。该方法有利于角色建模、运动仿真和行为控制等设计工作的分工协作,适合于网络环境下多角色、复杂动作的虚拟人仿真。     

A geometric comparison of algorithms for fusion control instereoscopic HTDs

This paper concerns stereoscopic virtual reality displays in which the head is tracked and the display is stationary, attached to a desk, tabletop or wall. These are called stereoscopic HTDs (head-tracked displays). Stereoscopic displays render two perspective views of a scene, each of which is seen by one eye of the user. Ideally, the user's natural visual system combines the stereo image pair into a single, 3D perceived image. Unfortunately, users often have difficulty fusing the stereo image pair. Researchers use a number of software techniques to reduce fusion problems. This paper geometrically examines and compares a number of these techniques and reaches the following conclusions: In interactive stereoscopic applications, the combination of view placement, scale, and either false eye separation or α-false eye separation can provide fusion control that is geometrically similar to image shifting and image scaling. However, in stereo HTDs, image shifting and image scaling also generate additional geometric artifacts that are not generated by the other methods. We anecdotally link some of these artifacts to exceeding the perceptual limitations of human vision. While formal perceptual studies are still needed, geometric analysis suggests that image shifting and image scaling may be less appropriate than the other methods for interactive, stereo HTDs     

Ergonomic evaluation of interaction techniques and 3D menus for the practical design of 3D stereoscopic displays

There has been a recent commercialization of 3D stereoscopic displays in order to implement them in a virtual reality environment. However, there is a lack of extensive research into user interfaces for 3D applications on stereoscopic display. This study focused on three representative interaction techniques (ray-casting, keypad and hand-motion techniques) utilizing a head-mounted display and 3D CAVE. In addition, the compatibility with 3D menus was also investigated based on performance and subjective assessment. Nine 3D menus were designed for the experiment in regards to three 2D metaphors (pop-up, pull-down and stack menus) and three structural layouts (list, cubic and circular menus). The most suitable technique for the 3D user interface on a stereoscopic display was the ray-casting technique and the stack menu which provided the user with good performance and subjective response. In addition, it was found that the cubic menu was not as effective as other menus when used with the three interaction techniques.Relevance to industryThis research describes a distinctive evaluation method and recommendations that guarantee the suitability for interactive 3D environments. Therefore, the results will encourage practitioners and researchers that are new to the area of 3D interface design.     

近距离3D人机交互技术研究实现

3D人机交互技术是计算机图形学、虚拟现实和模式识别的交叉融合领域,可分为虚拟环境的显示和三维物体识别。该研究将虚拟环境显示和三维物体识别整合成一个完整的解决方案并应用到1∶1模拟虚拟场景的近距离交互。研究了虚拟现实之间的坐标转换;分析了影响虚拟物体立体显示的三个主要因素：OpenGL中摄像机的张角,摄像机间距和立体图像对的产生;并实现了基于Intel Perceptual Computing的三维物体识别。实验结果显示：该方案在1∶1模拟虚拟场景方面具有良好的3D显示效果,同时在手势识别方面有较高的识别率。     

虚拟现实场景中立体视差生成算法的研究

近几年来,虚拟现实技术的广泛应用前景引起了国内外越来越多学者的兴趣和重视,而且国外的一些机构在这方面的研究也已经取得了一些很重要的成果。立体显示技术是虚拟现实的关键技术之一,而对视差的研究又是立体显示技术一个很重要的方面。该文首先论述了双眼的生理结构和双眼视差的形成以及计算机上实现立体视觉的原理,然后对虚拟现实中生成双眼视差得到立体图对的多种方法进行了研究,并在虚拟现实设备上实现,通过比较和分析各种显示效果给出了研究结论。     

Natural perception in dynamic stereoscopic augmented reality environments

Notwithstanding the recent diffusion of the stereoscopic 3D technologies for the development of powerful human computer interaction systems based on augmented reality environment, with the conventional approaches an observer freely moving in front of a 3D display could experience a misperception of the depth and of the shape of virtual objects. Such distortions can cause eye fatigue and stress for entertainment applications, and they can have serious consequences in scientific and medical fields, where a veridical perception of the scene layout is required. We propose a novel technique to obtain augmented reality systems capable to correctly render 3D virtual objects to an observer that changes his/her position in the real world and acts in the virtual scenario. By tracking the positions of the observer’s eyes, the proposed technique generates the correct virtual view points through asymmetric frustums, thus obtaining the correct left and right projections on the screen. The natural perception of the scene layout is assessed through three experimental sessions with several observers.     

基于矩阵变换的立体视频播放技术研究

立体图像按存储方式不同分为立体图片和视频,把左右格式立体图像准确传输到裸眼3D显示器的亚屏幕,是3D播放的关键技术。针对不同存储格式的立体图像,使用矩阵变换及视频融合算法,在FFmpeg函数库基础上构建立体视频播放器。实验表明该算法能将立体图像正确映射到左右眼亚屏幕。