共查询到19条相似文献,搜索用时 203 毫秒
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产品三维数据模型轻量化表示实现 总被引:4,自引:0,他引:4
提出一种能快速浏览的产品三维模型轻量化文件格式,文件中包含零件显示信息和几何信息·显示信息记录面的三角化模型和边的多边形模型,以加快模型的浏览速度,且按装配、零件、面、线、点层次关系进行组织;几何数据附加在显示信息上,提供几何数据的精确查询·文件大小通过数据压缩大幅度地减小,便于在网上发布·以此为基础开发了三维产品浏览系统和用于生成轻量化文件的接口程序· 相似文献
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软件安全逆向分析中程序结构解析模型设计 总被引:2,自引:0,他引:2
提出了一种基于二进制文件的程序结构解析模型。该模型通过对二进制文件反汇编,去除汇编文件中的冗余信息,对汇编文件进行静态分析,构建带有索引依赖信息的基本块,并以该基本块为基础提取二进制程序的内部控制流与函数调用关系信息,最后给出程序内部控制流图以及函数调用关系图。该模型不依赖程序的源文件,以二进制文件为分析对象,实用性和通用性比较好;实验结果表明模型对二进制程序内部结构解析具有较高的准确性。 相似文献
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针对大型拼接显示系统对PDF文件高分辨显示的需求,文中研究了集群并行高分辨信息显示平台的显示技术,分析了PDF在大屏显示系统中的重要性以及PDF文件格式和层次关系,研究并探讨了poppler库和mupdf库的优缺点,以及对PDF文件格式的解析与显示技术,并基于poppler库和mupdf库分别实现了PDF文件的解析和集群并行显示。通过对比实验,采用mupdf库能够更清晰、高效地实现PDF集群并行显示,验证了文中提出的PDF集群并行解析显示技术可极大地提高大型拼接显示系统对PDF文件的高分辨显示处理能力。 相似文献
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三维信息的共享成为热点:Adobe公司今年2月推出了支持三维模型的Acrobat 3D,可以将主流三维软件生成的零件和装配模型转换或者插入到PDF文件之中,并可以用免费的Acrobat Reader读取。此前,UGS公司已经推出了JT,Autodesk公司推出了DWF,达索系统则推出了3DXML。三维模型信息的共享,成为PLM领域的热点。 相似文献
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为修复因网络传输、磁盘损坏、病毒破坏等原因而受损的Zip文件,基于对文件格式和压缩算法的理解,深入讨论在Zip文件格式与数据严重受损情况下,阐述了一种挖掘出其中可用信息的方法,并提出了一种新的受损Zip文件修复技术。实验结果表明,该技术可以达到良好的修复效果。 相似文献
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通过对AutoCAD的DXF文件格式进行分析,设计了一种获取CAD文件信息的软件系统.与厂家原有的ERP系统集成,较好地解决了企业图纸信息的管理问题,简化了企业对图纸信息管理的复杂性,保证了企业信息的一致性,提高了图纸信息的重用效率.同时也使ERP纳入了产品数据管理PDM功能. 相似文献
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论文详细介绍了一种基于CAD超大模型的水电站虚拟现实仿真系统中的模型处理技术,并且成功应用于水电站仿真系统.通常虚拟现实平台对常用建模软件3dsMAX输出的fbx格式文件可以兼容导入,但许多水电站机组设备均采用了如Solidworks、CATIA等机械建模软件,此类软件建模精度高,但模型数据面巨大,并且导出的fbx模型很大概率出现破面,精度损失等情况,此项技术解决了水电站超大CAD模型在虚拟现实仿真系统中的应用问题,避免了重复建立三角面片模型,采取模型格式转换及自动轻量化的方式,使模型处理工作变得更加快捷、高效,转换后的模型可顺利导入至虚拟现实平台中并保留较高的精度. 相似文献
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U3D文件格式及运行机制剖析 总被引:2,自引:0,他引:2
通用三维文件格式(U3D)是一种可扩展的三维数据文件格式,其目的是为了使下游的3DCAD数据重用和可视化。它主要嵌入到其它文件格式中来显示三维数据,因此在许多主流的应用程序中极为有用。详细分析了这种文件格式及其运行机制,并通过一个写U3D文件的编程实例来进一步说明文件的构造方式。最后,还探讨了这种文件格式的优点及其应用。 相似文献
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Integrated reverse engineering and rapid prototyping 总被引:16,自引:0,他引:16
Reverse engineering is a methodology for constructing CAD models of physical parts by digitizing an existing part, creating a computer model and then using it to manufacture the component. When a digitized part is to be manufactured by means of rapid prototyping machines such as stereolithography apparatus (SLA) and selective laser sintering equipments (SLS), etc., it is not necessary to construct the CAD model of a digitized part. This will be described by the proposed novel method which can construct STL file (the de facto file format for rapid prototyping machines) directly from digitized part data. Further more, the STL file can even be constructed in a way that significant data reduction can be achieved at the users' discretion. 相似文献
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本文深入细致地分析了AUTOTRAX的PCB文件格式,这为把AUTOT-RAX转换成其它CAD文件格式及开发AUTOTRAX打下了基础。同时,对于开发其它CAD软件也有一定借鉴意义。 相似文献
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A database system of mechanical components based on geometric and topological similarity. Part I: representation 总被引:3,自引:0,他引:3
A database of mechanical components is an important issue for some manufacturing activities such as cost estimation, process planning, and design by case-based reasoning. In this paper, we give the representation scheme of the CAD model in such a database. Components are represented using attributed graphs in which the nodes correspond to the surfaces of the component and the links correspond to the edges of the component. The graph is based on the standard for the exchange of product information (STEP) physical file of the component. STEP file should be unique for a single component regardless of the underlying CAD system. The process of creating the graph of a component constitutes two sub-tasks: (i) importing the CAD model from the CAD system in STEP format and (ii) transforming the STEP data into attributed graph-based representation. The graph and its attributes describe the topology of the component completely together with some geometric data that are not dependent on any coordinate system such as surface type and curve type. These geometric data are helpful in the retrieval and matching processes in the database. 相似文献
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B. Starly Author Vitae Author Vitae W. Sun Author Vitae W. Lau Author Vitae Author Vitae 《Computer aided design》2005,37(4):387-397
Direct slicing of CAD models to generate process planning instructions for solid freeform fabrication may overcome inherent disadvantages of using stereolithography format in terms of the process accuracy, ease of file management, and incorporation of multiple materials. This paper will present the results of our development of a direct slicing algorithm for layered freeform fabrication. The direct slicing algorithm was based on a neutral, international standard (ISO 10303) STEP-formatted non-uniform rational B-spline (NURBS) geometric representation and is intended to be independent of any commercial CAD software. The following aspects of the development effort will be presented: (1) determination of optimal build direction based upon STEP-based NURBS models; (2) adaptive subdivision of NURBS data for geometric refinement; and (3) ray-casting slice generation into sets of raster patterns. The development also provides for multi-material slicing and will provide an effective tool in heterogeneous slicing processes. 相似文献
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Fusaomi Nagata Kazuhiro Takeshita Shingo Yoshimoto Akira Yoshinaga Shingo Kurita Akimasa Otsuka Keigo Watanabe Maki K. Habib 《Artificial Life and Robotics》2016,21(3):332-337
In this paper, viewer and converter softwares are presented for smart machining process using an industrial robot. The viewers for NC, CLS, DXF and STL files illustrate their surface representation with normal direction vectors. For example, the DXF is a data format developed by Autodesk to realize data interoperability among different makers’ CAD systems. The STL means Stereolithography which is a file format proposed by 3D Systems and recently is supported by many design tools and CAD/CAM softwares. In addition, the converters for DXF and STL files generate the corresponding CLS files with normal direction vectors for machining. Further, the proposed preprocessor allows the developed machining robot to work based on information included in STL files. The convenience and user-friendliness of the proposed integrated system are confirmed through experiments of viewing, converting and machining. 相似文献