Review on tabletop true 3D display

Tabletop three‐dimensional (3D) display is an attractive display technology that allows multiple individuals around the table to view the reconstructed 3D objects simultaneously, which can be applied to a variety of application scenarios such as desktop conference and board games. In this review paper, the tabletop true 3D display has been characterized and classified into four categories based on the technologies of light field display, integral imaging, and volumetric 3D and holographic 3D displays. Moreover, the comparisons of these technologies are listed, and the prospect of the tabletop 3D display is discussed.     

基于内容和语义的三维模型检索综述

多媒体信息的检索是信息复用的重要途径。三维模型检索作为三维建模过程中的关键技术之一,近年来随着三维建模的广泛运用而被深入研究。针对目前三维模型检索技术的进展,首先介绍了基于内容的检索技术,按照提取的特征将其分为四类：基于统计数据、基于几何外形、基于拓扑结构和基于视觉特征,分别介绍各类技术的主要成果和优缺点;然后介绍考虑语义信息,解决“语义鸿沟”现象的基于语义的检索方法,根据切入角度将其分为三类：相关性反馈、主动学习和本体技术,随后介绍了各类技术的相互关系与特点;最后总结和提出了三维模型检索的未来研究的发展方向。     

三维动画技术与三维虚拟技术的研究

目前三维图形技术主要包括两大类：三维动画技术和三维虚拟技术。该文的目的是研究两种技术的开发原理，并通过对两种技术的对比，进一步说明了三维虚拟仿真技术在实时性、交互性方面的优势。该文首先介绍了三维动画技术的应用原理、开发步骤，重点阐述了三维虚拟技术中的实时显示技术和交互技术，给出了虚拟仿真应用的开发方法及基于两种技术的应用实例，并对两种技术在实时性、交互性、时间性和三维建模效果等方面作了比较，最后展望三维虚拟技术的发展方向。     

3D树木建模技术研究进展

3D树木建模一直都是计算机图形学、计算机视觉、虚拟现实等领域最具有挑战性的研究方向之一,国外学者在该领域做了大量研究工作,但3D树木建模综述性文章的缺乏成为其发展的制约因素。侧重从计算机视觉的角度,将当前国内外经典的3D树木建模方法分为基于图像,基于规则和基于草图等三类,并跟踪了最新的3D树木建模技术进展,对他们的成果进行了深入剖析,重点阐述3D树木建模关键技术。最后,分析和比较了几种主要的3D树木建模技术,提出轻量化3D树木建模技术是今后虚拟场景中的交互应用的发展趋势。此外,根据当前研究的难点提出了基于单张图像的轻量化混合建模的研究思路。     

Optical characterization of autostereoscopic 3‐D displays

Abstract— Display‐measurement methods different from conventional 2‐D display measurements are needed for verifying the optical characteristics of autostereoscopic (3‐D) displays and for comparing different 3‐D display technologies. Industry is lacking standardized measurement methods, and the reported results can not always be compared. The selected set of characteristics discussed in this paper and partly defining the quality of the 3‐D experience are crosstalk, viewing freedom, and optimum viewing distance. Also, more conventional display characteristics such as luminance are discussed, since the definitions for these characteristics in 3‐D mode usually differ from those used for the 2D displays. We have investigated how these chosen 3‐D display characteristics can be objectively measured from transmissive two‐view and multiview 3‐D displays. The scope of this article is to generally define those basic characteristics as well as the different measurement methods. Most of the 3‐D characteristics can be derived from the luminance and colors versus the viewing angle. Either a conoscopic or a goniometric measurement system can be used, as long as the angular and stray‐light properties are suitable and known. The characteristics and methods are currently discussed in the display‐quality standardization forums.     

三维视频压缩研究进展

信息压缩是信息传输过程中的一个关键环节,随着三维显示和三维视频技术的发展和完善,未来的视频传输将不仅限于二维视频。但是,三维视频的数据量很大,这就给三维视频的传输带来了阻碍。因此,设计出高压缩比、高压缩效率的三维视频压缩技术,不但可以解决三维视频的传输问题,而且有利于促进三维视频及三维显示领域的进一步发展。本文系统地讨论了目前三维视频压缩技术的研究进展,在对各种技术特点研究的基础上,提出了进一步的研究和发展方向。     

Guest Editors' Introduction: New Dimensions in 3D Integration

Although various forms of 3D fabrication technology have existed for a few decades, only in recent years have researchers developed highly integrated 3D design technologies that are potentially manufacturable and economically feasible. Several companies are already marketing 3D structures built by wafer stacking, where the distance between the 3D layers on a wafer are on the order of the wafer thickness. But 3D technology must also surmount several challenges, such as exploiting the design space to build high-performance systems and architectures to gain the fullest advantage achievable. The articles in this special issue highlight these advances and challenges, providing an excellent snapshot of the state of 3D technology as it stands today.     

基于SDL & OpenGL的三维游戏优化技术

跨平台三维游戏的开发技术及其优化技术引起了关注和讨论。该文以一款具体的跨平台三维游戏设计为例，分析了游戏中的各种功能实现及优化技术，包括纹理技术、列表技术、高级字体技术、反走样技术以及绘制顺序的优化策略等，通过运用这些优化技术，得到了较好的游戏结果。     

基于SDL & OpenGL的三维游戏优化技术

跨平台三维游戏的开发技术及其优化技术引起了关注和讨论。该文以一款具体的跨平台三维游戏设计为例，分析了游戏中的各种功能实现及优化技术，包括纹理技术、列表技术、高级字体技术、反走样技术以及绘制顺序的优化策略等，通过运用这些优化技术，得到了较好的游戏结果。     

基于光场扫描的真三维立体显示系统的开发

近年来,计算机视觉领域出现了一种新型的三维显示技术,即光场三维显示技术。基于光场扫描的真三维立体显示系统通过重构物体光强的空间分布,减少了信息冗余,采用高速投影仪、定向散射反射镜和高速旋转马达等设计而成。通过分析光场三维显示原理和系统工作原理、显示系统架构和立体成像原理等,详细论述了显示系统开发的可行性,并通过实验证明了当达到一定投影输出功率和马达旋转功率时可实现立体成像。观测者可360度裸眼观测立体图像,并且无需佩戴任何辅助工具。     

基于结构光的三维成像技术

就结构光三维成像的基本原理展开讨论,就投影图案的不同对结构光三维成像技术进行分类,对于每一类中选取其中具有代表性的几种方法进行描述,并给出三维成像技术的性能评价指标,对不同方法进行比较。介于定标精度对最终重建精度有着决定性的意义,我们对基于结构光三维成像系统的定标方法也作了简单介绍。     

基于D3D立体镜显示器图像生成算法研究

介绍了自动立体镜显示器的结构及其三维显示的原理,研究了基于D3D技术的自动立体镜三维图像生成原理,对点蒙板方法做了深入的研究,给出了九片图中观察角度、位置以及视点观察空间的变换运算公式,在分析其优缺点的基础上提出了改进算法。并对最终图像的合成算法作了改进。在自动立体镜显示器上分别用原始方法、点蒙板方法、以及改进的点蒙板方法对图像进行显示,并在显示前准备时间、一帧图像渲染时间、三维深度感觉三方面对三者进行了对比实验。     

基于三维GIS的大屏可视化策略

本文分析了三维地理信息系统和大屏展示系统的现状及特点, 以通用性的综合展示平台为例, 选取南宁市数字孪生可视化展示为主题, 从空间信息场景设计、表达对象选取、页面布局、平台色彩设计、符号设计、图表设计、动效设计的角度切入, 提出了基于三维GIS的大屏可视化策略. 并基于上述策略, 对该类型平台搭建的系统架构和关键技术点...     

The impact of Web3D technologies on medical education and training

This paper provides a survey of medical applications that make use of Web3D technologies, covering the period from 1995 to 2005. We assess the impact that Web3D has made on medical education and training during this time and highlight current and future trends. The applications identified are categorized into: general education tools; tools for diagnosis; procedures training; and collaborative training. A summary of work that has been carried out to validate these tools is also included in the survey.     

Key design issues for autostereoscopic 2‐D/3‐D displays

Abstract— Flat‐panel 2‐D/3‐D autostereoscopic displays are now being commercialized in a variety of applications, each with its own particular requirements. The autostereoscopic display designer has two key considerations to address in order to meet customer needs — the optical output of the display (defined by the output window structure) and the choice of optical components. Window structure determines 3‐D image resolution, achievable lateral and longitudinal viewing freedom, crosstalk, and 3‐D fringe contrast. Optical‐component selection determines the quality of the imaging of such windows, viewing distances, device ruggedness, thickness, and brightness. Trade‐offs in window design are described, and a comparison of the leading optical component technologies is given. Selection of Polarisation Activated Microlenses? architectures for LCD and OLED applications are described. The technology delivers significant advantages particularly for minimising nominal viewing distances in high pixel density panels and optimizing device ruggedness while maintaining display brightness.     

Computer-Generated Graphite Pencil Rendering of 3D Polygonal Models

Researchers in non-photorealistic rendering have investigated the display of three-dimensional worlds using various display models. In particular, recent work has focused on the modeling of traditional artistic media and styles such as pen-and-ink illustration and watercolor painting. By providing 3D rendering systems that use these alternative display models users can generate traditional illustration renderings of their three-dimensional worlds. In this paper we present our graphite pencil 3D renderer. We have broken the problem of simulating pencil drawing down into four fundamental parts: (1) simulating the drawing materials (graphite pencil and drawing paper, blenders and kneaded eraser), (2) modeling the drawing primitives (individual pencil strokes and mark-making to create tones and textures), (3) simulating the basic rendering techniques used by artists and illustrators familiar with pencil rendering, and (4) modeling the control of the drawing composition. Each part builds upon the others and is essential to developing the framework for higher-level rendering methods and tools. In this paper we present parts 2, 3, and 4 of our research. We present non-photorealistic graphite pencil rendering methods for outlining and shading. We also present the control of drawing steps from preparatory sketches to finished rendering results. We demonstrate the capabilities of our approach with a variety of images generated from 3D models.     

矿物晶体标本的三维可视化展示设计与实现

矿物晶体标本具有很高的科研和观赏价值,但使用传统拍照技术在观赏和研究矿物晶体时,仍存在时间和空间上的限制。三维可视化展示技术可以使用户通过对鼠标或触摸的控制,实现上下、左右多个维度的移动和放缩,实现 360 度任意视角观察标本,极大地满足矿物晶体参观者和研究者的需求。本文介绍了目前三维可视化展示的技术方法,包括 WebGL 技术、全景技术、3D 打印技术和三维云展示技术。并且以国家岩矿化石资源共享平台矿物晶体标本的三维展示技术——环物摄影技术为例,阐述了三维展示技术在矿物晶体标本展示中的应用,详细介绍了环物摄影技术的设计过程与实现方式。     

Direct light field rendering without 2D image generation

Rapid developments in 3D display technologies have enabled consumers to enjoy 3D environments in an increasingly immersive manner through various display systems such as stereoscopic, multiview, and light field displays. However, there is a corresponding increase in the complexity of the conventional multiview rendering process in the attempt to achieve a sufficient level of reality, which may hinder the further commercial viability of 3D display products based on such a conventional approach. This paper proposes a novel method, the so‐called direct light field rendering, which can compose the display 3D panel image without reconstructing all the multiview images beforehand. Interpreting the 3D display as sampling in the light field domain, we attempt to directly compute only the necessary samples, not the entire light fields or multiview images. Our proposed algorithm involves the solving of linear systems of two variables, thereby requiring remarkably low computational complexities. Experimental results show that the computation time and memory usage remain as little as 12% and 1% of those required by the conventional one.     

Curved OLED display to effectively enhance natural3D

We studied the stereoscopic effect obtained from a two‐dimensional image without using binocular parallax, which we call “natural3D” (n3D). Unlike a parallax‐based three‐dimensional (3D) display system, n3D causes less tiredness and is free from a decrease of the resolution by half because of image division and viewing position dependence. To make the display with these effects comfortable to use, we conducted statistical tests with sensory evaluation experiments and a quantitative evaluation based on physiological responses. These examinations revealed that the n3D effect can be effectively obtained by using, for example, the characteristics of an organic light‐emitting diode display, such as high contrast and easy bendability. This study discusses optimal display curvatures for displays of different sizes that enhance n3D and reduce tiredness, which are revealed through statistical tests. In addition, we performed an experiment with a frame called an n3D window (n3Dw) that is placed before the display such that a subject views the display through the opening of the frame. We found that the combination of a curve and the n3Dw causes n3D more effectively.     

Analysis of angular dependence of 3‐D technology using polarized eyeglasses

Abstract— The cause of the angular dependence of 3‐D technology that requires the use of eyeglasses with linear or circular polarization is analyzed. For 3‐D technology that requires the use of eyeglasses, anisotropic media such as a polarizer or retardation film determines the polarization state. Therefore, the angular behavior of 3‐D display performance is also affected by the characteristics of the anisotropic media that have intrinsic angular dependence. Various conditions of the optic axes of the imaging display and eyeglasses are investigated to understand their effect on 3‐D display performance. The result shows that some conditions of the optic axes can cause non‐negligible degradation of 3‐D display performance.