学科发展研究(2012-2013)分述
图学
2014年04月02日

  一、概述

  (一)图学的产生

  图是人类获得知识的重要来源,也是人类描述思想与交流知识的重要工具,图样更是科学技术界的语言,用于传递设计与加工的构想。近年来图与计算机技术和信息技术紧密结合,使图的理论、技术和应用获得了快速发展,形成了一门新的学科——图学,并在工农业生产、科学研究、国防、教育、文化产业中得到了广泛的应用。

  (二)图学的研究对象

  图学的研究对象是图,主要研究图与形的关系。这里“形”是指形体或形状,形存在于客观世界(如自然界的物体、人造的物体、自然现象等),也存在于虚拟世界(如动画、游戏等),它的本质是“表示”。图是形的视觉表现,由具有颜色等属性信息的线、点构成画面,它的本质是“表现”。因此,形是图之源。

  (三)图学的定义

  图学是以图为核心,研究将形演绎到图,由图构造形的过程中图的表达、产生、处理与传播的理论及其应用的科学。

  (四)图学的学科体系

图学学科体系

  图学的学科体系由图学基础层、应用支撑层、图学应用层三层结构和图学教育与图学标准两个支撑组成,如上图所示。图学基础层包括图学公共基础、图学计算基础和图学理论。应用支撑层包括图形应用基础软件、图形库等。图学应用层包括广泛的应用领域,例如:工程和产品设计制图、图形设计、图形创意、地理图学、信息可视化等。

  (五)图学学科的地位

  在我国的《学科分类与代码》GB/T 13754-72中,有关图的理论、技术和应用分散在许多学科中,因此,有必要适时建立一个图学新学科来改变这种分散的状态。报告论述的这个“图学”新学科具有“大图学”的概念,“大”体现在其理论和技术研究涉及各种各样的图,其应用覆盖到各行各业。由此认为,图学与文学和数学一起共同支撑着科学与工程的发展。

  二、本学科近年来研究进展

  (一)图学理论的研究进展

  1.在图学基础理论方面。图学基础理论包括形构建理论、将形变成图的理论、图处理理论,以及由图构造形的理论等。报告选择立体线图的计算机理解是因为它是近几年国内外研究的热点。计算机理解立体线图的研究内容包括草图识别、立体线图标记、不完整立体线图的完整、面识别、从立体线图恢复三维实体的结构形状信息、基于模型从立体线图识别三维实体、三维实体美化等问题。我国在这方面取得了以下成果:(1)自主研发了一个在线手绘图识别系统,其创新包括笔划分割、单笔划识别、多笔划识别和手绘三维物体投影图的端点融合的机理和算法等;(2)提出了一种新的三面顶点流形曲面立体画隐线图的标记方法;(3)给出了从画隐立体线图搜索所有简单回路和识别面的递归算法;(4)提出了计算机理解立体线图的方法,定义了一种称为弦高点的特征点,基于该特征点构造了一种曲线局部描述符,并将其用于曲线匹配。

  此外,在图形变换方面取得了如下三项重要研究成果:(1)提出了一种图形变换几何化表示的方法;(2)修正了“投影”与“投影变换”理论;(3)较好地解决了透视参数的定量定值问题。

  2.在图学计算基础方面。基于“形是表示,是输入,图是展现、是输出”的基本认识,指出形与图的基本元素是几何,形的构造与图的形成的本质是几何定义、构造、度量和显示。因此,图学计算的对象是几何,图学计算的本质是几何计算。剖析了图形计算的矛盾,找出了图形计算的关键,构造了图学计算的公共基础。提出了一个基于“几何问题几何化”的几何计算理论体系与实施框架。在几何计算理论、形计算机制以及几何计算稳定性理论方面取得了具有中国特色的重要研究成果。

  (二)图学应用的研究进展

  1.图学应用模式方面。我国在图学应用模式研究上取得了两项进展,一是面向产品生命周期的集成应用模式,二是面向行业的“嵌入式图形核心”模式。另外,解决了面向产品生命周期集成应用模式的相关技术,如:工程语义特征的存储与提取、三维模型的装配与展示以及集成技术等;分析了面向行业的“嵌入式图形核心”模式及其技术,并以国产Ti3DCore图形核心系统为例,阐述了该系统在建筑行业体纹理真实感渲染和布尔运算库中的应用。叙述了我国在图学应用方面取得的成绩和存在的问题。指出图学应用的平台化、集成化、知识化、服务化和全球化发展方向,并提出了相应对策。

  2.图学的基于模型定义技术方面。基于模型定义(MBD)技术是图学技术应用的最新阶段,它是一种面向计算机将与产品相关的设计定义、工艺描述、制造信息和管理信息等都附着在产品三维模型上的先进的数字化定义方法。此外,报告叙述了我国在MBD数据集内容的完整性、MBD数据的组织和管理、MBD数据集的传输等方面取得的进展。我国企业如中国商用飞机有限责任公司、沈阳飞机工业(集团)有限公司、中国南车股份有限公司、中国北车股份有限公司等都分别进行了MBD技术的实施应用,取得了很好的效果。

  3.图学在土木建筑中的应用方面。报告指出了土木建筑行业应用建筑信息模型(BIM)技术是CAD技术应用的深化和必然发展的结果;从计算机辅助土木建筑设计、建筑信息模型(BIM)、可视化和虚拟现实、科学计算可视化四个方面详细说明了它们在土木建筑行业中的应用情况。虚拟现实技术目前主要应用在设计、施工和装修三个领域中对大型复杂工程项目的规划、投标、报批和管理;用于建筑小区三维导航、户型展示、全景鸟瞰、园林景观展示等方面。科学计算可视化主要应用在建筑声光热分析、计算流体力学、结构有限元分析、地震等方面实现分析结果数据的可视化。报告中还展示了我国几个复杂建筑工程项目应用上述技术的实例。

  4.图学在可视媒体中的应用方面。报告介绍了图学与可视媒体技术之间的关系及可视媒体技术的重要性。指出可视媒体最新的研究热点有三个,它们是:(1)媒体内容的处理、检索与合成;(2)三维高效逼真建模;(3)虚实融合场景生成与交互。报告还说明了最近5年来我国在上述三个关键技术问题上所取得的成果,并用实例和图片加以展示。

  (三)图学学科两个支撑的研究进展

  1.图学教育方面。图学教育是图学学科的支撑,其作用是为图学学科设置完整的教育体系,以及为图学学科的发展培养各类图学人才。报告界定了图学教育的范畴,认为凡是“关于图的表达、产生、处理与传播的理论、技术与应用”都属于图学教育的范畴,并着重指出传统的工程图学教育是图学教育的重要组成部分;指出了图学基础教育的地位如同数理化、外语、计算机一样,共同构成了学校教育的公共基础平台,共同担负着培养学生基本素质的重任;展示了近年来图学教育研究所取得的四个进展,分别是:图学教育思想方面、工程图学课程内容与体系的改革方面、图学教育为社会服务方面、图学课程建设获得的奖励和荣誉方面等;此外,还叙述了图学教育在图学数字化建设中取得的进展,例如网络和多媒体系统、考试系统、虚拟实验室、模拟演示与训练系统等。

  2.图学标准方面。报告中的图学标准主要指机械制图、建筑制图、土木制图、电气制图、船舶制图等各类技术图样、技术文件和图形符号的标准,以及图形交换、产品几何技术规范等的标准。图学标准为改进产品设计、防止技术贸易壁垒、促进技术进步提供了技术规范保证。

  自2009年至2011年我国先后发布和实施了17项三维数字化设计标准,填补了我国三维图学标准化空白,标志着我国在“计算机辅助设计和制图”标准化技术领域达到了与国际同步。此外,由我国主持制定并已发布的国际标准有 3个,主持制定和立项的国际标准有5个,参与制定的国际标准有6个,标志着我国标准化研究水平达到了国际先进水平。

  三、本学科国内外研究进展比较

  (一)图学学科内涵的研究进展比较

  图学学科内涵的研究包括图学的产生、研究对象、定义、学科体系、学科地位等问题,对此,国外尚无系统的论述,而我国学者则有比较系统的研究和清晰的认识。

  (二)图学基础理论与技术研究进展比较

  图学重要的基础理论与技术有图元生成、图形生成与显示、造型等,国外已有成熟技术,我国也已掌握了这些理论与技术。我国有效跟踪国际图学最新的研究方向,包括科学计算可视化、虚拟现实和增强现实、计算机动画、数码艺术等;发表了许多具有国际先进水平的论文,也取得了许多应用成果。我国存在的问题是:(1)理论研究方面,在国际上的地位还不高;(2)应用方面,仍存在着照搬国外的模式、技术和软件;(3)研究方面,缺乏来自我国企业的强大需求刺激与支持,导致研究动力不足,基础不厚。

  (三)图学计算基础研究进展比较

  我国学者认为图的本质是几何,图学的计算基础是几何计算。与国际上通用的几何代数化方法不同,我们已经建立了“几何问题几何化”的几何计算的全新理论框架及整套实用算法,用来处理几何表示、几何创建和几何计算中的各种问题。

  (四)图学应用基础研究进展比较

  图学高新技术的应用进入我国晚了约20年。因此,我国在工程和产品设计领域、地理信息领域、艺术领域、动漫与娱乐领域中,图学的应用与国外先进国家相比还有较大差距。但改革开放以来,国内经济蓬勃发展,以图形高科技为核心,我国几个大的图形产业市场正在形成,有二、三维CAD软件市场、地理信息软件市场、动漫产业市场等。

  三、本学科的发展展望

  在新的社会需求和科技进步的推动下,图学发展展望如下:

  1.图形和图像的结合将更为紧密。图形图像融合的绘制方法以及图像特征抽取以及图形要素综合处理的技术,将在交叉应用需求驱动下结合更为密切,这也将为多学科交叉及融合提供最为重要的载体。

  2.动画和视频将实现无缝的虚实融合。视觉层面的虚拟世界和物理世界的界限将会消失,多维视频处理将逐步发展到覆盖虚实信息结合的综合处理方式,大数据将成为信息处理方面的重要技术。

  3.基于增强虚拟现实的人机交互方式将更为自然。通过手势、语音、力触感等多模式的自然交互方式将得到广泛应用,多通道交互手段的综合协调将成为重要研究问题,带来人类手足的触及的延伸,认识自然的能力进一步增强。

  4.信息可视化方式将在大数据处理模式的支持下走向更多实际应用。大数据处理模式的发展将直接推动可视化技术的发展和扩展,而大数据与云计算、物联网以及它们的结合将成为大型系统构造的主要形式,面向多维数据融合的信息可视化将成为应用构造及表现的常规手段。

  5.3D打印对制造业带来巨大的机遇和挑战。3D打印将改变传统产品研发的模式和周期,加快产品创新节奏,概念层面的竞争将会加剧,覆盖完整产品生命周期的现代工业设计应用将得到更多重视和发展。


  Graphics

  Graph is not only an important source of knowledge for human being, but also an important tool for describing thought and communicating knowledge among people. Some kind of graph, like engineering drawing, is seemed as a language to the science and technology community expressing the idea of design and manufacturing. In recent yeas, because of the closely connecting with computer and information technology, the theory, technology and applications of Graph are developed rapidly, thus a new discipline named Graphics is formed, and it gets widely applications in industry, agriculture, scientific research, defense, education and culture, etc.

  GRAPHICS is a science which takes GRAPH as object to research the theory, technique and applications about graphic representation, generation, treatment and transfer during the process of producing graph from shapes, or constructing shapes from graph.

  The object of GRAPHICS research is GRAPH, and the work of research is to find out the relationship between graph and shapes. Here, the“SHAPES”refer to the form or object, which exists in the objective world (such as natural objects, man-made objects, natural phenomena, etc.), and virtual world (such as animation, game, etc.), and the essence of SHAPES is “presence”. GRAPH is a visual representation of SHAPES, which is consisted of dots and lines with their own attributes like color, line width, etc., and the essence of GRAPH is “representation”. Therefore, it can be said SHAPES is the source of GRAPH.

  The disciplinary frame of GRAPHICS is consisted of three layers and two supporting components. The three layers are base layer, application support layer and application layer. The two supporting components are graphics education and graphics standard. The base layer contains graphics common base, graphics calculation base and graphics theory. The application supporting layer includes graphics basic application software, graphics libraries, etc. The application layer contains a wide range of applications, such as engineering and product design drawings, graphic design, creative graphics, geographical graphics, information visualization, etc.

  Owing to the introduction of computers, the original boundaries between the two subjects “Graphics” and “Image” have been increasingly blurred, also the contents of both subjects have been more and more merged together, so it is possible using GRAPHICS to unify both subjects. In addition, in China’s “Discipline Classification and Code” (GB/T 13754-72), the information about graphic theory, technique and applications spreads across in many disciplines, which is not benefit to develop graphic theory and technology, therefore, timely to establish a new discipline of GRAPHICS is necessary. For this new discipline, the report presents a concept of “Big GRAPHICS”, and here the “Big” means that the research of graphics theory involves various graphs, and applications of graphics cover a wide range of fields. Therefore, the role of this “Big GRAPHICS” could be recognized as same as Literature and Mathematics to support the development of science and engineering together.

  In recent years, many progresses have been made in graphic theory, technology and applications as follows.

  15.1 The foundation of graphics theory

  The progress has been made in understanding line drawings by computer, which includes transferring sketches into line drawings, labeling nodes and line type of line drawings, recognizing surfaces of line drawings, and using quantitative method for understanding line drawings. Moreover, three important research achievements have been obtained in graphic transformation, i.e. presenting a geometric representation method for graphic transformation, amending the theory of “projection” and “projection transformation”, and solving the parameter setting problem for perspective drawings.

  15.2 The foundation of graphics computing

  Based on the cognition “Shapes is present and input; Graph is representation and output”, it can be pointed that the basic element of Shapes and Graph is geometry, and then the essence of Shape’s construction and Graph’s formation are geometry definition, geometry structure, geometry measurement and geometry display, therefore the object of graphics is geometry, and the essence of graphics computing is geometric calculation. It is also noted that the graphics computing involves “numerical calculation” and “shape calculation”. In addition, other progresses have been made in geometric calculation theory, mechanism of shape calculation and stability theory for geometric calculation.

  15.3 The application modes of graphics

  Two application modes of graphics have put forward. The first one is integrated application mode in product life cycle, and the second one is the system embedded with graphic core system for certain application. Meanwhile, some examples of two modes used in industry are showed.

  15.4 Graphics application

  The new progresses have been made in following applications: digital design and manufacturing, building information mode (BIM), geographic information technology, visual media technology, etc. Two practical cases are given. One is to show the use of graphics in the whole life cycle of ship building including ship hull design, performance calculation, process design, manufacturing, inspection and maintenance. Another is to show the effect of using BIM in architectural industry.

  15.5 Graphics education

  The new progresses in graphics education are obtained in graphics thinking, reform of curriculum contents and system, digital teaching, simulation training, social graphics education, team teaching, etc.

  15.6 Graphics standardization

  Seventeen items of standards for digital design had issued and implemented from 2009 to 2011 in China. This fills the gaps of 3D graphics standards in China, and marks the country has reached international level in standardized technique for “computer aided design and drafting”. In recent yeas, three international standards formulated under the auspices of China have issued, five topics international standards decided to formulate have also been under the auspices of China, and other six international standards will be formulated with China’s being member country . The above shows that China has reached international advanced level in standardized research.

  The progresses of graphics research at home and abroad are compared at four aspects, namely research on the discipline connotation of graphics, research on the basic theory and technology of graphics, research on the calculation basis of graphics, research on the application basis of graphics.

  Finally, the report puts forward five aspects of future trends for graphics development, which include graphics and animation, image and video, virtual reality and augmented reality, visualization, 3D printing. The corresponding countermeasures are proposed also.