Parametric Curves and Surfaces eryar@163.com Abstract. This paper is concerned with parametric curves and surfaces definitions, such as singular point and regular point and their application in OpenCascade. The two most common methods of representing
NURBS 曲线和曲面参数化 什么是参数? 参数是曲线或曲面上点的唯一数值(类似于坐标).通过参数,可以沿曲线的长度方向引用特定点.参数值越大,点在曲线方向上的距离越远. 就像空间中的点具有三个维度(称为 X.Y 和 Z),点的参数是沿着曲线的一个内部维度(长度)测得的.我们将该维度称为 U. 由于曲面具有两个内部维度(长度和宽度),因此,我们需要除 U 之外的另一个参数才能指定曲面上的点.我们将该参数称为 V. 沿曲线长度方向上的每个点都有一个 U 参数,同样,曲面上的每个点都有 U 和 V
Convert BSpline Curve to Arc Spline in OpenCASCADE eryar@163.com Abstract. The paper based on OpenCASCADE algorithms to approximate the NURBS curve to arc spline. The method is most useful in numerical control to drive the cutter along straight line
Make Helix Curve in OpenCASCADE eryar@163.com Abstract. OpenCASCADE does not provide helix curve directly, but you can build a helix curve by the pcurve of a surface(curve on surface). When you understand the pcurve of a surface, you can make a helix
OpenCASCADE BRepTools eryar@163.com Abstract. OpenCASCADE BRepTools provides utilities for BRep data structure. OuterWire method to find the outer wire of a face. Dump method to dump a BRep object. It also can be used as the data exchange for OpenCAS
OpenCASCADE Hidden Line Removal eryar@163.com Abstract. To provide the precision required in industrial design, drawings need to offer the possibility of removing lines, which are hidden in a given projection. OpenCASCADE provides two algorithms for
OpenCASCADE Coordinate Transforms eryar@163.com Abstract. The purpose of the OpenGL graphics processing pipeline is to convert 3D descriptions of objects into a 2D image that can be displayed. In many ways, this process is similar to using a camera t
OpenCASCADE Make Primitives-Sphere eryar@163.com Abstract. The sphere is the simplest topology shape of the BRep structure. But there are several import concept of the sphere edges, such as degenerated edge and seam edge. So construct a sphere by cod
OpenCASCADE BRep vs. OpenNURBS BRep eryar@163.com Abstract. BRep short for Boundary Representation. First give the definition of the BRep, then compare the BRep mode between OpenCASCADE and OpenNURBS. There are 3 main representation method: use face/
OpenCASCADE DataExchange DWG eryar@163.com Abstract. DWG is a file format created in the 70’s for the emerging CAD applications. Currently it is the native file format of AutoCAD, a proprietary CAD program developed by Autodesk. Libredwg is a free C
OpenCASCADE Curve Length Calculation eryar@163.com Abstract. The natural parametric equations of a curve are parametric equations that represent the curve in terms of a coordinate-independent parameter, generally arc length s, instead of an arbitray
Conversion Operators in OpenCascade eryar@163.com Abstract. C++ lets us redefine the meaning of the operators when applied to objects. It also lets us define conversion operations for class types. Class-type conversions are used like the built-in con
Mesh Algorithm in OpenCascade eryar@163.com Abstract. Rendering a generic surface is a two steps process: first, computing the points that will form the mesh of the surface and then, send this mesh to 3D API. Use the Triangle to triangulate the param
Introduction of OpenCascade Foundation Classes Open CASCADE基础类简介 eryar@163.com 一.简介 1． 基础类概述 Foundation Classes Overview 本文将对Open CASCADE中的基础类进行介绍及如何使用基础类.更多信息可访问其官网:www.opencascade.org/support/training/. 基础类库提供了一些通用功能,如自动动态内存管理.集合.异常处理.泛型编程和plug-in的
OpenCascade HLR for Pipe Model eryar@163.com 摘要Abstract:在工厂辅助设计(Plant Design)或船舶辅助设计(Ship Design)等CAD设计软件中建完模型后都会出安装图或制作图,这也是这类辅助设计软件的最终的一个输出,还有再就是输出材料数据用来对物资进行管理.OpenCascade提供的Hidden Line Removal算法可以对模型进行隐藏线消除,此功能可用来生成制作图和安装图.本文通过实例演示了HLR算法的效果. 关键字K