摘要：Abstract. Rational Bezier Curve can represent conic curves such as circle, ellipse, hyperbola, .etc. But how to convert a conic curve to BSpline curve is still question, i.e. Represent a conic curve in BSpline form. Parabola curve is the most simple conic curve, that the parabola does not require rational functions. Let’s begin from the simplest one... Key Words. OpenCASCADE, Convert, Parabola, BSplineCurve, Conic Curve 阅读全文

摘要：Abstract. Numerical integration is the approximate computation of an integral using numerical techniques. The numerical computation of an integral is sometimes called quadrature. The most straightforward numerical integration technique uses the Newton-Cotes formulas(also called quadrature formulas), which approximate a function tabulated sequence of regularly spaced intervals by various degree polynomials. If the functions are known analytically instead of being tabulated at equally spaced inter 阅读全文

摘要：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 variable like t or u. According to the natural equations, the curve length is the integration of the curve parametric equation’s derivation. So the core algorithm for curve length calculation is the numerical integration method. OpenCASCADE use Gauss-Legendre to calculate the integration for single v 阅读全文

摘要：Abstract. B-splines are quite a bit more flexible than Bezier curves. This flexibility comes from the fact that you have much more control over the basis functions. For Bezier curves that each control point had an effect on each point on the curve; likewise the number of control points affected the degree of the curve. For the sake of flexiblity, you would like to be able to arbitrarily set the degree of the curve and to also determine the range of the affect each control point has. B-splines al 阅读全文

摘要：Abstract. OpenCascade use the Jacobi method to find the eigenvalues and the eigenvectors of a real symmetric square matrix. Use class math_Jacobi to computes all eigenvalues and eigenvectors by using Jacobi method. The exception NotSquare is raised if the matrix is not square. No verification that the matrix is really symmetric is done. Key words. Eigenvalues, Eigenvectors, OpenCascade, Matrix, Jacobi method, 阅读全文

摘要：摘要Abstract：分析幂基曲线即多项式曲线在OpenCascade中的计算方法，以及利用OpenSceneGraph来显示OpenCascade的计算结果，加深对多项式曲线的理解。 关键字Key Words：OpenCascade、PLib、OpenSceneGraph、Polynomial Library 阅读全文

摘要：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 conversions to implicitly convert an object of one type to another type when needed. A conversion operator provides a way for you to define how an object can be converted automatically to a different type. The paper gives some conversion operators examples in OpenCascade. Key words. OpenCascade, Con 阅读全文

摘要：gp是几何处理程序包（Geometric Processor package），简称gp。包gp提供以下功能： •代数计算；如坐标计算、矩阵计算； •基本解析几何元素；如变换、点、矢量、线、面、轴、二次曲线和初等曲面； 这些实体同时在二维和三维空间中定义，且包中的类都是非持续的（non-persistent），即这些类的实例都是以值的方式处理而不是引用。 阅读全文

摘要：OpenCascade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的创建。 阅读全文

摘要：摘要Abstract：本文对矩阵作简要介绍，并结合代码说明OpenCascade矩阵计算类的使用方法。 关键字Key Words：OpenCascade、Matrix、C++ 阅读全文

摘要：摘要Abstract：本文简要介绍了数学表达式解析求值的几款开源软件，并结合程序代码说明了OpenCascade中表达式包的用法。也简要介绍了表达式解析求值在AVEVA Paragon模块中的应用。 关键字Key Words：Expression, Paragon, OpenCascade Expr package, muParser, MTParser 阅读全文

摘要：在几何建模的过程中，程序创建和删除了大量的对象在动态内存中，也就是堆中。在这种情况下，标准C++的内存管理方式不是很高效，所以Open Cascade在包Standard中专门写了个内存管理程序（Memory Manager）来对内存的分配与删除进行管理。 阅读全文

摘要：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的创建。 阅读全文