Java 3D—Java语言的三维图形解决方案

Java 3D是一种新型的三维图形编程方案,结合Java语言,在开发Internet及WWW上的三维图形网络应用有极大优势。本文介绍了Java3D API的特点,并结合一个利用Java 3D开发的实例说明其结构与编程模式。     

Java3D API与Java3D编程技术

Ｊａｖａ３Ｄ ＡＰＩ是应用于３Ｄ图形编程的Ｊａｖａ类包,本文具体介绍Ｊａｖａ３Ｄ ＡＰＩ中主要类的使用,Ｊａｖａ３Ｄ编程模式和显示模式,阐明了Ｊａｖａ３Ｄ编程的思路和方法。     

面向Java 3D的CAD模型简化与转换

三维图形仿真的一个重要工作就是建立三维模型,若使用已有的模型可以节省一定的时间.文中主要讨论了如何将复杂的CAD模型应用于Java3D建立的图形仿真系统中.首先,对已有的Pro/E模型进行简化,以VRML格式导出,有两种方式应用于Java3D中.一种是直接编辑Pro/E模型导出的VRML格式文件,组织模型之间的链接关系;另一种是将Pro/E模型导出的VRML格式文件导入到3DMax中组织链接关系,然后导出为单一文件.最后联合使用这两种方式将一个复杂的空间机器人模型导入到Java3D,提高了图形数据的重用性和开发的快速性,经实践验证效果理想.     

面向真三维立体显示的数字微镜器件应用研究

数字微镜器件(DMD)专门用于对空间光进行振幅和相位调制.针对DMD特有的MEMS结构和μs级响应速度,提出将DMD作为空间光调制器(SLM)来实现高性能真三维立体显示系统.研究了DMD的工作原理,进行了DMD专用显示控制模块和通用控制算法的设计,实验结果表明:DMD响应速度远远优于振镜,用DMD构建简洁型的真三维立体显示系统,对提高系统处理速度和显示性能是非常有利的.     

Towards harnessing theories through tool support for hard real-time Java programming

We present a rationale for a selection of tools that assist developers of hard real-time applications to verify that programs conform to a Java real-time profile and that platform-specific resource constraints are satisfied. These tools are specialised instances of more generic static analysis and model checking frameworks. The concepts are illustrated by two case studies, and the strengths and the limitations of the tools are discussed.     

基于Java3D的不规则形体三维造型及真实感处理

针对Java3D只具有规则形体的三维造型类,无法完成不规则形体的三维造型这一问题,提出用小面片来逼近曲面实现回转体的造型,提出一种变截面曲柄的三维造型方法,同时实现了渲染和真实感处理,是对Java3D功能的必要扩充。     

Visual experience for autostereoscopic 3D projection display

In order to investigate visual experience for watching the autostereoscopic three‐dimensional (3D) projection display, we conduct a subjective evaluation experiment by a questionnaire when viewing video clips. Factor analysis is adopted to classify the evaluation items for the perpetual constructs of visual experience. Then a mixed design with repeated measurement analysis of variance with dimension and display duration as factors is carried out on the evaluation data to check the factorial effects and interactions for statistical significance. The results of factor analysis extract five factors including visual comfort, image quality, distortion, naturalness, and presence, which can be used as comprehensive indicators to evaluate the autostereoscopic 3D projection display. The results of analysis of variance indicate that image quality, which is used to assess two‐dimensional contents, is no longer applicable. It is necessary to give consideration to depth when evaluating 3D visual experience. Although 3D scenes enhance the overall subjective performance such as naturalness and presence, the health issues and stereoscopic distortion related to the introduction of depth cannot be ignored.     

基于Java3D的地质资源的三维模拟

传统的地质勘测绘制方法是将地质资源数据绘制到平面图上,地质资源的三维可视化是目前的研究方向。本文利用Java3D开发包将地质资源数据绘制成三维图形。采用逐点插入法来实现大量的离散数据的三角网格化,以此实现三维图形的显示;并设计算法,在特定位置的显示剖面图。在此基础上开发了一个实用系统。     

Java 3D可视化技术及其应用

Java3D是Java语言在三维领域的扩展,本文较为详细地阐述采用Java3D语言对三维实体进行可视化显示的方法及具体实施,并着重分析了三维实体的颜色处理及灯光效应,通过实例说明多种三维实体表面着色的方法及效果。程序既可以是应用程序也可以在互联网上运行,展示出来的结果是交互的,可以改变观测角度及任意缩放、平移。本文具体说明了该方法的实施过程。本文的方法可以应用于多种领域,比如计算机远程教学、三维立体模型显示及科学计算的可视化等。     

Web-based visualization of 3D geospatial data using Java3D

Spatial database servers allow for the storage and access of 3D geospatial data using open geospatial consortium standards. The Geospatial Database Online Visualization Environment (GeoDOVE) is a prototype 3D Web-based geographic information system that demonstrates how Java3D can reduce bandwidth and allow direct connectivity to spatially enabled database systems. We've developed GeoDOVE, a Java3D-based prototype system that retrieves geospatial data from conventional spatial database servers, allows modification of the visualization during runtime, and lets users remotely modify attributes using the structured query language (SQL).     

The Java 3D API and virtual reality

Java programmers can quickly and easily define graphics programs using Java 3D's scene graph classes. An expanded view model lets applications seamlessly operate in a variety of single- and multiple-display, nonhead-tracked and head-tracked, display environments. This view model relies on the flexible InputDevice interface that Java 3D provides to remove most of the vagaries of hardware trackers     

基于Java 3D的交互式三维动画的研究

为了建立基于工程图学的虚拟实验室,在计算机的屏幕上虚拟现实中零件的装配,笔者通过对两种虚拟语言VRML与Java 3D的分析比较,选定以Java 3D为虚拟平台,在引入.obj文件的基础上,按照现实中零件的安装和工作过程,通过设定相应的程序来实现零件的交互和装配过程,并完成了对零件交互式三维装配动画以及工作原理的论述。以压板为例,给出了一个基于Java 3D的交互式三维装配动画的例子,实现了该装配体在虚拟现实中的要求,达到了虚拟装配的目的。从而验证了该方法在现实零件装配中的预见性和优越性。     

Java3D技术在三维服装设计中的应用

随着服装工业的发展,三维服装CAD技术得到广泛的应用,通过三维人体测量建立人体三维数据模型,在虚拟的三维人体上进行交互式立体设计,最后完成二维平面服装衣片。大大提高了服装工业产品设计的水平和生产的效率。本文叙述了利用强大的Java3D技术进行三维显示和设计的基本原理和方法。     

See in 3D: state of the art of 3D display technologies

With advances in lasers, optics, and electronics, many new 3D display technologies have been proposed with prototypes in research labs or have entered the marketplace. Although some of these technologies (such as Stereoscopy) are familiar to people, other technologies, such as holography, remain far-fetched to most. This survey introduces the principles of current popular 3D display technologies, which are generally categorized into four categories: 3D movies, on-stage holograms, holographic projections and volumetric 3D displays. Furthermore, the limitations of each of the aforementioned technologies are deeply analyzed, and comparisons of these technologies are provided. Moreover, we note appropriate application situations for the various technologies. Because computer-generated hologram (CGH) technologies are considered to be the next generation of 3D display technology and have become a dominant direction in 3D display technology development, we address the challenges that CGH is currently facing and provide an insightful analysis of solutions proposed in recent years. Finally, we study the current 3D display applications associated with the four categorized technology principles.     

Human shape recognition performance for 3D tactile display

The paper describes the relationship between the pin-matrix density of a tactile display and the recognition performance of displayed 3D shapes. Three types of pin-matrix tactile display, that generate 3D shapes, were used for the experiment. The pitch of pins was 2 mm, 3 mm, 5 mm each. We assumed that surfaces, edges, and vertices were primitive 3D shape information, so tested shapes were classified into these three categories. We assumed two types of finger touching mode: 1) fingertip-only, allowed full use of spatial shape information given to the fingertip; and 2) allowed tracing of the object. Recognition time and the classified error rate were measured. We obtained results on the relationship between pin pitch and recognition performance data. Regression curves for pin pitch and recognition time were plotted. A significance test of recognition time versus pin pitch was done. The error rate of identification versus pin pitch was described. Our results provide basic knowledge for developing tactile presentation devices     

A device driver for display terminals

The special editing ability of display terminals is seldom exploited outside of display-based text editors. Tailoring a device driver in the operating system kernel to display terminals makes display editing available whenever the terminal is used and makes display editors simpler and terminal-independent. This paper describes such a device driver.     

JaVa 3D中的Text2D的扩展与应用

Java3D中Text2D类虽然能生成二维文本,但由于文本的字体、字号、颜色在文本生成后就不可改变,字的排列也只有“从左向右”方式。所以,Text2D不能满足交互式建立虚拟环境中二维文本的需要。Java3D中的Text3D类支持交互式地建立文本,但Text3D的三维文本却不能退化为二维文本,这使得Text3D不能替代Text2D。所以,有必要扩展Text2D类以支持交互地建立虚拟环境中二维文本。文章给出实现这一扩展的关键技术,为用Java3D开发交互式虚拟环境建模器的二维文本生成功能提供支持。扩展的Text2D在智能型虚拟汽车驾驶道路环境建模器中的使用表明它是有效的。     

基于Java 3D的自重构机器人仿真平台的构建

介绍了新设计的一种同构阵列式模块化自重构机器人的模块结构和运动方式,针对这种机器人系统,为了验证控制算法,构建了可视化的自重构机器人仿真平台。选用Java 3D作为开发工具,采用类的封装和线程技术,设计了仿真平台的软件结构,并实现了在界面上进行交互式地显示三维运动过程。在此平台上对模块的运动进行仿真,给出了一个4×2×2矩形阵列模块的平移仿真示例,验证了该仿真平台的有效性。此仿真平台界面简单,操作方便,能够实现算法仿真和运动显示。