Embedding 3D models of biological specimens in PDF publications

By providing two examples, the option for embedding 3D models in electronic versions of life science publications is presented. These examples, presumably representing the first such models published, are developmental stages of an evertebrate (Patella caerulea, Mollusca) and a vertebrate species (Psetta maxima, Teleostei) obtained from histological section series reconstruction processed with the software package Amira. These surface rendering models are particularly suitable for a PDF file because they can easily be transformed to a file format required and components may be conveniently combined and hierarchically arranged. All methodological steps starting from specimen preparation until embedding of resulting models in PDF files with emphasis on conversion of Amira data to the appropriate 3D file format are explained. Usability of 3D models in PDF documents is exemplified and advantages over 2D illustrations are discussed, including better explanation capabilities for spatial arrangements, higher information contents, and limiting options for disguising results by authors. Possibilities for additional applications reaching far beyond the examples presented are suggested. Problems such as long-term compatibility of file format and hardware plus software, editing and embedding of files, file size and differences in information contents between printed and electronic version will likely be overcome by technical development and increasing tendency toward electronic at the cost of printed publications. Since 3D visualization plays an increasing role in manifold disciplines of science and appropriate tools for the popular PDF format are readily available, we propose routine application of this way of illustration in electronic life science papers.     

Development of a Stereolithography File Interface with ArtCAM™

This paper presents the technique used for converting a 3D ArtCAM™ relief file into the stereolithography (STL) format. This 3D file is obtained from a 2D picture using a 3D CNC engraving software called ArtCAM™. The problem is to convert the 3D relief files into an STL format without compromising the accuracy and details of therelief. This paper discusses the size of the files which have been converted, and steps taken to reduce the file size by reducing the number of triangles or facets in the STL file. The discussion involves the verification of the converted model by comparing it with the original relief. The problems associated with the reduction of triangles when the file has been converted to STL format are also discussed.     

利用CAD图形交换文件实现激光直写设备的运动控制

分析了激光写入与加工设备的特点.指出了这类设备工作效率低下的主要原因是要求刻划或加工的图形变换的频率高,而这类设备的加工元件的编程语言不标准,程序采用人工编制,且加工工艺复杂,从要求刻划与加工的图形到设备的多维运动控制代码的产生是一件非常繁琐的过程.提出了采用CAD绘图功能作为加工轨迹输入,在CAD绘图环境中加入设备运动的辅助信息,然后产生相应的DXF图形交换文件,并开发图形交换文件到运动代码生成的解释软件,利用CAD与解释软件相结合可实现设备的运动代码自动生成,可极大地提高编程效率,缩短调试时间,提高设备的利用率.同时给出实现此方案的步骤与途径.     

基于网络的多用户协同设计CAD系统

介绍了自行研发的、基于Web的、多用户协同的二维CAD系统。该系统使用Java语言开发,不同的用户可以通过组合消息的机制实现同步显示、在线协同创建和编辑。由于实现了DWG格式文件的导入、打开、编辑和保存,该系统实现了与AutoCAD软件的交互。系统采用了基于实体的权限控制机制,解决了协同设计中的冲突问题。三层式B／s结构使用户无须安装客户端,即可使用支持Java的浏览器,极大地方便了用户的使用。     

Integration of sketch-based conceptual design and commercial CAD systems for manufacturing

Sketch-based modeling is a very important step towards a complete design process digitalization. For a complete digitalization, integration of sketch-based design modeling and commercial CAD systems is being a necessity. This is because of the need of detailed modification and refinement for the 3D models created by sketching. The integration can speed up the design process and affect competition between companies. In this paper, we present a new method to achieve the integration between sketch-based interfaces and commercial CAD systems by using gesture-based sketch modeling techniques for producing 3D conceptual design models and then translating the 3D models into CAD systems with feature recognition through IGES exchange files. Gesture-based modeling method was used because it works in a similar way to feature-based design approach and it is easy to extract features from its 3D models. IGES file format was used for exchanging 3D geometric model information because it is widely available within commercial CAD systems for data exchange and it also can express features and hierarchy information. 3D models were created with a gesture-based sketch interface for modeling and then information was extracted from it. After that, information was translated into IGES entities which were organized in a specific order in an IGES file. This information can be inputted into commercial CAD systems and recognized as a feature-based model with feature recognition embedded within CAD systems. To evaluate the proposed method, we conducted four case studies. In these case studies, we created 3D models and then transferred them into Autodesk Inventor as a commercial CAD system. After the CAD system recognized the 3D models successfully, we applied some modifications on the 3D models such as changing dimensions, positions and drafting to demonstrate the effective integration.     

AutoCAD2000的数据交换与文件格式转换

介绍了通用绘图软件AutoCAD2000的数据交换和文件格式转换的方法，并分析了各种文件格式的特点及应用。     

某型舰炮拨弹机虚拟仿真教学系统的研究

介绍了一种桌面式虚拟仿真训练教学系统,其具体的实现途径是:利用三维造型软件Pro/E建立机体零件的三维实体几何模型,然后将其导出STL格式文件,通过3D MAX软件进行格式转换,导出ASE格式文件,再通过VC++6.0和OpenGL从ASE文件导入零件数据,最后利用OpenGL编程完成模型的显示与控制,生成人机交互的仿真教学界面。利用该系统可实现在虚拟环境中的拨弹机拆卸实验。     

基于ObjectARX的工艺文件编辑报表工具的研究与实现

工艺文件编辑报表工具是CAPP系统中一个重要的模块。这里提出一种利用 ObjectARX实现的工艺文件编辑报表工具,该工具支持工艺文件图文并排、并允许用户自定义工艺文件格式。在简单介绍 ObjectARX的基础上,研究了工艺数据格式化组织、模板定制、工艺文件编辑与在线资源查询等关键技术。最后给出了应用实例。     

基于虚拟DSP的开放式数控系统加工仿真研究

介绍了在Windows平台上用Visual C 编程开发的一种基于虚拟DSP的数控加工仿真系统.该仿真系统包括:数控代码预处理模块、虚拟DSP模块、内存映射文件、加工仿真模块.其工作流程是:"虚拟DSP"通过虚拟定时中断,实时地接收预处理模块传来的操作指令和编译后的NC数据.经过虚拟DSP的虚拟插补器的插补运算与虚拟软件PLC的数字I/O逻辑处理之后,将插补后的动态坐标数据和刷新的数字I/O信号传输到内存映射文件.加工仿真模块定时地从内存映射文件中读取数据,根据这些数据绘制出二维和三维刀具轨迹仿真图形.实例仿真结果表明所开发的仿真系统软件是成功的.     

工程图像的矢量化技术

工程图样的自动矢量化是CAD领域尚未解决的关键技术之一.本文通过对平面二维的工程图样进行了分析,介绍了图像二值化、修饰处理、边缘检测、骨架化、矢量化,编制了自动矢量化算法,并描述了主要函数的功能,该算法将彩色或灰度图样自动转化为直线与圆弧,再由CAD/CAM软件生成NC代码.     

UG工程图与AutoCAD的数据转换

UG作为一种功能强大的CAD／CAE／CAM软件，在很多情况下，它与其它二维CAD软件的数据转换是非常必要的。这里论述了UG工程图和二维CAD软件AutoCAD的数据转换方法。主要通过CGM为中间图形格式，将UG工程图模块生成的二维工程图转换成AutoCAD的DWG格式的文件，实现了两者之间的无缝转换。     

一种从器件三维实体到工艺版图的MEMS CAD技术

研究了标准三维实体文件和版图文件的格式,在此基础上提出了一种在MEMS CAD中从三维实体到工艺版图的转换方法,实现了直接基于文件到文件的三维实体到工艺版图的转换,使用C++语言开发了相应的转换接口。通过典型MEMS器件——微机械加速度计和微机械陀螺的多种结构,验证了三维实体到二维版图转换的可行性与效率。结果表明,这种转换方法切实可行,且效率较高,为实现MEMS自顶向下与基于任意流程的设计方法、简化版图绘制、提高设计效率提供了一种有效的途径。     

在Auto CAD R14中创建标准件图形库

利用 Auto CAD R14绘图软件将机械工程中常用的标准件 ,如螺钉、螺母、垫圈等制做成标准图形 ,并集成一个图形文件库。然后制做成图标菜单或工具条 ,以解决工程技术人员在制图中重复性绘图造成的浪费 ,提高其绘图的工作效率     

一种油液分析仪器数据文件内容解析方法*

在状态监测与诊断领域,需要利用油液分析方法进行特征获取,但这些仪器需要用自带的软件才能进行数据的查看操作。为摆脱该约束,设计一套利用API函数获取仪器软件窗体中控件的位置坐标和具体内容,再以控件间坐标相对关系确定其具体含义,以控件中的具体内容作为搜索值,自动获取特征值在文件中位置的辅助格式解析方法和工具。该工具能将特定分析仪器产生的文件以二进制格式打开,通过依次提取二进制文件中的4个连续字节,并依据浮点数存储格式进行转换,将转换数值与搜索值进行比对,从而输出特定内容在文件中的保存位置,进而解析出文件的存储格式。以光谱分析仪器数据为例进行算法测试验证,表明算法可行,能正确分解出仪器数据的存储格式,为进行文件格式解析和信息提取提供了一种新的思路。     

利用AutoLISP编制图框并结合SolidWorks绘图

论述了包括如下三个要点的工程图绘制方法：首先在AutoCAD工程图绘制过程中利用AutoLisp的编程自动生成设置有图层、线型、颜色、字体和比例等绘图环境参数的标准图框;其次结合SolidWorks构建实体快捷、生成二维图形精确的优点,由三维实体直接转化为二维的工程图;最后在AutoCAD二维图里标注尺寸、粗糙度和焊接符号等必要图形元素完成二维工程图的绘制。     

网络协同产品开发环境中的三维工程图形批注技术

针对一般批注软件不能解决的三维工程图形批注问题，提出将Windows API函数与图层覆盖技术相结合，实现网络环境下产品协同开发过程中的三维工程图形实时批注工具。论述了批注源图形文件的提取、批注元素编辑及批注文件的入库等关键技术。最后，介绍了异地协同产品开发环境中批注工具的应用。     

Pro/E与AutoCAD的数据交互在智能I/O模块产品设计中的应用

提出一种基于Pro/E和Auto CAD软件数据交互模式的产品设计方法——在AutoCAD模式下绘制好产品外形轮廓草图,将绘制好的草图导入到Pro/E绘图环境中进行相关产品外形轮廓草图,以产品核心部件作为参照创建其产品外形轮廓草图,设计完成的三维立体图可以直接转化为AutoCAD可识别的格式进行存档。此方法在有效地防止设计过程中极易出现的零部件干涉现象,保证了零部件之间的精确配合。通过在智能I/O模块产品设计过程中的应用,证明了此种设计方法的高效性和实用性。     

基于Pro/E的圆柱滚子轴承参数化结构设计

基于滚动轴承重复设计率高,以Pro/E的记录文本文件为软件开发的接口,开发了圆柱滚子轴承参数化结构设计软件。在轴承的外径、内径、宽度等基本尺寸确定后,软件将在外部数据库的支持下按照输入的设计参数确定内部几何结构尺寸参数、计算运动参数,最终实现圆柱滚子轴承三维造型和产品图的输出。开发过程简便易行,编程工作量小。     

Adaptive direct slicing of a commercial CAD model for use in rapid prototyping

Slicing a 3D graphic model into layers of 2D contour plots is an essential step for all rapid prototyping (RP) machines. Various methods are available, such as stereo lithography (STL) file slicing, direct slicing and adaptive direct slicing. Amongst these, adaptive direct slicing is the most advanced for its capability of adapting the slicing thickness according to the curvature of any contour. In this study, an adaptive direct slicing method complete with the algorithm for calculating the thickness of each layer is proposed. As an illustration of the method, the algorithm was programmed within the commercial CAD software package, PowerSHAPE. The method was shown to be fast and accurate in comparison with STL file slicing and direct slicing, which both used a constant layer thickness. An erratum to this article can be found at     

NURBS曲线在快速原型制造系统中的应用

大多数快速原型制造系统采用 STL 文件作为与 CAD系统之间的数据交换接口。但是 ,STL 文件是通过用一系列的三角片逼近实际零件表面而产生的 ,STL 文件本身及其创建过程均存在许多问题。要提高模型的精度 ,就必须增加三角片的数量 ,同时减小三角片的尺寸。这必然造成 STL 文件庞大 ,后续处理时间较长 ,而且易产生缺陷 ,使后续处理不能进行。针对上述问题 ,本文分析了 STL文件的不足 ,提出一种 CAD系统与 RPM系统之间新的数据交换方法。该方法对 CAD系统中的真实模型直接切片 ,将切片后所得到的轮廓数据作为 CAD系统与快速原型制造系统之间的数据交换接口。该切片算法已在“超人 2 0 0 0 CAD/ CAM”系统中实现 ,算法表现稳定