SimCrane 3D+: A crane simulator with kinesthetic and stereoscopic vision

Crane operation training using virtual crane simulators has been introduced in the last decade. It can reduce the costs associated with renting actual cranes and enables operator training for a range of tasks in virtual environment. However, a critical drawback common to most existing simulators is a lack of realistic simulation for the depth perception, which usually relies on stereoscopic vision and head motion to increase the precision of depth perception. This research aimed at adopting kinesthetic vision and stereoscopic vision into a virtual crane simulator to increase its training effectiveness. Kinesthetic vision generates corrected perspective images based on the head position of the viewer. Stereoscopic vision is to generate separated images for left and right eyes respectively. A crane simulator known as SimCrane 3D⁺ was developed and implemented to achieve the goal. We performed user tests to evaluate the proposed system by both subjective and objective factors. The results showed that the system provide better simulation for depth perception. Operators increase their confidences in the tests. They also reported using SimCrane 3D⁺ is more intuitive than the simulator without stereoscopic or kinesthetic visions.     

Stereoscopic ray-tracing

In this paper, we describe a method to create an approximate ray-traced stereoscopic pair by transforming a fully raytraced left-eye view into an inferred right-eye view. Performance results from evaluating several random scenes, which indicate that the second view in a stereoscopic image can be computed with as little as 5% of the effort required to fully ray-trace the first view, are presented. We also discuss worst-case performance of our algorithm and demonstrate that our technique is always at least as efficient as two passes of a standard ray-tracer.     

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。     

基于OpenGL的烟花动态模拟方法的研究与实现

给出了几种模拟动态烟花的方法。通过分析烟花燃放过程的特点，建立了用粒子系统模拟烟花的模型，提出了基于粒子系统的烟花的实时模拟生成算法。实验结果表明，该方法满足实时性和逼真性的要求。     

基于物理的图形建模研究

逼真性是虚拟现实的重要特性,也是虚拟现实研究的难点。基于物理的图形建模是实观虚拟环境中物体逼真运动的基本方法,它构建动画角色的动力学模型并通过仿真计算它们的运动。该方法在视频制作、虚拟仿真、虚拟漫游等领域中具有重要的应用价值。与其它运动表示方法相比,可以实现虚拟环境中多种更为逼真的物体运动效果。该文分别以不变形物体（刚体）和变性物体（柔体）为例,介绍了虚拟现实系统中实现逼真物体运动的基于物理的建模思想,分析了它们的特点以及各自存在的问题和局限性。最后指出了要想理想解决物体建模问题所必须进一步研究和突破的若干技术。     

Coarse-to-fine stereo vision with accurate 3D boundaries

This paper presents methods for efficient recovery of accurate binocular disparity estimates in the vicinity of 3D surface discontinuities. Of particular concern are methods that impact coarse-to-fine, local block-based matching as it forms the basis of the fastest and the most resource efficient stereo computation procedures. A novel coarse-to-fine refinement procedure that adapts match window support across scale to ameliorate corruption of disparity estimates near boundaries is presented. Extensions are included to account for half-occlusions and colour uniformity. Empirical results show that incorporation of these advances in the standard coarse-to-fine, block matching framework reduces disparity errors by more than a factor of two, while performing little extra computation, preserving low complexity and the parallel/pipeline nature of the framework. Moreover, the proposed advances prove to be beneficial for CTF global matchers as well.     

虚拟塑料注塑成型教学系统

塑料注射成型技术的发展与注射模具设计人员需求的增长十分迅速，模具设计人员学习必要的塑料成型基本原理是掌握注射模具设计方法的现实需要。该文在虚拟现实（VR）技术的基础上，结合基于三维模型的注塑成型FEA技术、面向对象的编程技术和OpenGL图形库，研究并实现了沉浸式、交互式的虚拟塑料注射成型教学仿真系统（VPIM），提出了立体成像算法，给出了模拟注射成型过程运动仿真的方法，借助VR外设及通过建立知识化、数字化、可视化、现实化的教学平台来提高设计人员的学习效率、学习兴趣及对问题理解的深入程度。     

虚拟环境产生器及其立体图像的成像技术

本文对虚拟现实系统的虚拟环境产生器的功能，作了介绍，重点介绍了几种立体图像的快速成像技术，并实现了一个立体图实例。     

体视图像生成算法的研究及应用

在立体视觉系统中，一般采用空间分离且同步旋转的两台摄像机拍摄同一物体，为观察者提供同一物体的两个不同角度的图像。文章从人类的视觉感知原理出发，给出了基于单幅图像的体视图像生成算法，并成功地用于大数据量体视转换的场合，如“国家大剧院”和“奥运会场景”的漫游仿真，从而实现虚拟复杂场景的仿真漫游。该算法特别适合于要求快速、一次绘制（拍摄）的场景，即再现立体的场合。     

基于VC 6.0和OpenGL的3DS文件的读取与控制方法

本文介绍了在Visual C 下如何使用OpenGL读取和控制3Ds Max生成的三维模型的方法.     

虚拟现实在AUV运动控制研究中的应用

基于软件平台Vega和Creator开发出AUV循迹航行的视景仿真系统。研究了虚拟现实技术和AUV循迹控制相结合的技术,文中详细描述了其硬件系统的组成、系统软件的选择、模型的建立、虚拟海洋环境的生成,以及应用软件的设计与实现。仿真结果表明,该系统能逼真的演示出AUV循迹航行的全过程,并能满足不同情况下的仿真需要。     

基于VC＋＋6.0和OpenGL的3DS文件的读取与控制方法

本文介绍了在Visual C＋＋下如何使用OpenGL读取和控制3Ds Max生成的三维模型的方法。     

信息系统模拟数据生成研究综述

信息系统模拟数据生成是提供信息系统试验、试用和演练中所需数据的重要途径。通过与软件测试数据生成、样本数据扩充、虚拟现实相关研究领域比较，讨论了信息系统模拟数据生成的研究定位;归纳了信息系统模拟数据生成的研究内容;提出了具有数据层、中间层和生成层三层结构的典型信息系统模拟数据生成系统结构框架;最后对信息系统模拟数据生成的研究方向进行了展望。     

虚拟现实中立体视觉的研究

本文研究了空间视觉中的立体线索,阐明了立体视觉深度的形成原理,并基于立体透视投影推导了有关的计算公式。     

Estimating Color and Texture Parameters for Vector Graphics

Diffusion curves are a powerful vector graphic representation that stores an image as a set of 2D Bezier curves with colors defined on either side. These colors are diffused over the image plane, resulting in smooth color regions as well as sharp boundaries. In this paper, we introduce a new automatic diffusion curve coloring algorithm. We start by defining a geometric heuristic for the maximum density of color control points along the image curves. Following this, we present a new algorithm to set the colors of these points so that the resulting diffused image is as close as possible to a source image in a least squares sense. We compare our coloring solution to the existing one which fails for textured regions, small features, and inaccurately placed curves. The second contribution of the paper is to extend the diffusion curve representation to include texture details based on Gabor noise. Like the curves themselves, the defined texture is resolution independent, and represented compactly. We define methods to automatically make an initial guess for the noise texure, and we provide intuitive manual controls to edit the parameters of the Gabor noise. Finally, we show that the diffusion curve representation itself extends to storing any number of attributes in an image, and we demonstrate this functionality with image stippling an hatching applications.     

Visual accommodation and subject performance during a stereographic object task using liquid crystal shutters

Virtual reality has become popular in a variety of fields. Three experiments to study visual accommodation and task performance during stereographic vision were carried out in order to better understand the human response to virtual reality. Visual accommodation to stereograms on CRT was studied. Subjects could see the target on the CRT display binocularly through liquid crystal shutters. Accommodation to a stereogram with step changes in distance was tested first. As the second experiment, accommodation to a stereogram with gradual changes in distance, and comparison of ability to perform a colour photograph stereogram task were tested. Finally, accommodation and subject performance during a prolonged stereographic object task were observed for 30min. A virtual ‘gate’ was formed at a position 1.2?m from the subject. The virtual target moved forward and backward through this gate between the positions of 0.8?m and 20?m. The subjects were asked to focus on the target and press a button as it moved through the virtual gate. Subjective response to the task and the error between the position where the button was pressed and the gate was recorded. It was concluded that there are some people who exhibit large changes in accommodation while performing a stereographic task. There is a tendency to accommodate to a distance nearer than the baseline. Prolonged stereoscopic viewing caused visual fatigue or loss of accommodation and diminished task performance.     

基于图形与图像的混合绘制技术

随着虚拟现实技术的发展,对基于图形与图像的混合绘制技术提出了越来越高的要求。基于图形与图像的混合绘制技术是虚拟现实、动态仿真、实时可视化、高品质动画等越来越多的图像、图形应用技术的实现基础。该文对各种基于图形与图像的混合绘制技术进行分类综述、研究和展望。     

机器人手眼立体视觉标定研究

以固高GRB-400型机器人和CCD组成机器人手眼系统,分析了摄像机的成像模型,采用了基于直接将图像坐标映射到机器人参考坐标的“黑箱”思想,从图像坐标直接计算出目标位置的方法,用于立体定位的摄像机手眼标定,该方法通过保持机器人末端执行器到机器人参考坐标系旋转矩阵来简化复杂的相机标定过程,最后通过实验验证了该方法的可行性,并分析了实验误差产生的原因,并提出了相应的解决措施。     

三种体视图像生成方法的比较研究

简要介绍了生成体视图像的3种方法，平移，柱面变换和球面变换，并着重对同一方法取不同参数生成的体视图像效果以及3种方法生成的较好体视图像效果进行了比较，以得到较好的算法及较好的参数匹配，并对算法指出了改进方向。     

Interactive augmented reality system for enhancing library instruction in elementary schools

Due to limited budgets and manpower, most elementary schools in Taiwan do not plan or provide library instruction for students. Although students can use libraries, they typically lack the knowledge needed to use library resources effectively. Consequently, students have difficulty finding the books they need and can easily become overwhelmed by the massive amount of information in libraries. Computer-assisted instruction for teaching basic library skills to large numbers of students is an appealing method. Particularly, developing augmented reality (AR) technologies for learning have garnered considerable attention in education research. Many researchers and scholars believe that integrating teaching and AR enhances student learning performance and motivation. This work develops an educational AR system based on situated learning theory, and applies innovative augmented reality interactive technology to a library’s learning environment. Student library knowledge can be enhanced via the proposed augmented reality library instruction system (ARLIS). Experimental results demonstrate that student learning performance is improved significantly by using the proposed ARLIS. Moreover, this work demonstrates that using the proposed ARLIS for library instruction results in the same learning performance as conventional librarian instruction and there is no gender difference on learning performance between the proposed ARLIS and conventional librarian instruction. Moreover, the proposed library instruction system overcomes shortcomings of personal teaching skills of librarians that may adversely affect student learning performance by conveying the same learning content to all students. Additionally, the proposed system results in better learning performance for learners with the field-dependent cognitive style than learners with the field-independent cognitive style. Further, the proposed system provides more benefits in terms of library skills of application and comprehension than conventional librarian instruction. Moreover, the learning performance of students is not affected by their gaming skills. Therefore, student gaming skills do not need to be considered when adopting the proposed system in library instruction programs.