OpenCASCADE 参数曲线曲面面积 eryar@163.com Abstract. 本文介绍了参数曲面的第一基本公式,并应用曲面的第一基本公式,结合OpenCASCADE中计算多重积分的类,对任意参数曲面的面积进行计算. Key Words. Parametric Curve, Parametric Surface, Gauss Integration, Global Properties 1.Introduction 我们知道一元函数y=f(x)的图像是一条曲线,二元函数z=f(x,y)

OpenCASCADE Ring Type Spring Modeling eryar@163.com Abstract. The general method to directly create an edge is to give a 3D curve as the support(geometric domain) of the edge. The curve maybe defined as a 2D curve in the parametric space of a surface

OpenCascade Primitives BRep-Cylinder eryar@163.com Abstract. BRep is short for Boundary Representation. Boundary Representation gives a complete description of an object by associating topological and geometric information for solid modeling. In this

Geometry Surface of OpenCascade BRep eryar@163.com 摘要Abstract:几何曲面是参数表示的曲面 ,在边界表示中其数据存在于BRep_TFace中,BRep_TFace中不仅包括了几何曲线,还包含用于显示的离散几何信息,如三角剖分数据.本文主要对OpenCascade的BRep表示中几何曲面进行说明,将在后面分析Topology部分的读写程序时来说明包含几何数据的三种拓朴结构中分别包括哪些几何信息. 关键字Key Words:OpenCasca

SineSurface直译为正弦曲面.这有可能和你想象的正弦曲线不一样.如果把正弦曲线绕Y轴旋转,得到的该是正弦波曲面.这个曲面与上一节中的罗马曲面有些相似,那个是被捏过的正四面体,这个则是个被捏过正方体. 本文将展示SineSurface与粽子曲面的生成算法和切图,使用自己定义语法的脚本代码生成数学图形.相关软件参见:数学图形可视化工具,该软件免费开源.QQ交流群: 367752815 这是从http://mathworld.wolfram.com/SineSurface.html上找到的一种

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

Surface Normal Averaging eryar@163.com 摘要Abstract:正确设置网格面上点的法向,对几何体在光照等情况下显示得更真实,这样就可以减少顶点数量,提高渲染速度.本文通过将OpenCascade中的形状离散成网格数据后在OpenSceneGraph中显示,及使用OSG的快速法向osgUtil::SmoothingVisitor优化与使用OpenCascade来计算正确的法向的结果的对比,说明面法向量的重要性. 关键字Key Words:OpenCascade

OpenCASCADE构造一般曲面 eryar@163.com Abstract. 本文主要介绍常见的曲面如一般柱面(拉伸曲面).旋转面在OpenCASCADE中的构造方法,由此思考一般放样算法的实现. Key Words. Common Surface, Extrusion, Revolution 1.Introduction 实体Solid就是由面组成,面中包含几何曲面,常见的几何曲面有平面,柱面,旋转面等.对几何曲面有一些功能要求:如计算指定参数u,v处的点,切线等,即求指定参数u,v处的

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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 PCurve of Topological Face eryar@163.com Abstract. OpenCASCADE provides a class BRepBuilderAPI_MakeFace to build topological faces. A face maybe built from a surface, elementary surface from gp package, surface from Geom, from a wire and

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 Conic to BSpline Curves-Hyperbola eryar@163.com 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 con

OpenCASCADE Conic to BSpline Curves-Parabola eryar@163.com 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 coni

OpenCASCADE Rational Bezier Curves eryar@163.com Abstract. Although polynomials offer many advantages, there exist a number of important curve and surface types which cannot be represented precisely using polynomials, e.g., circles, ellipses, hyperbo

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

OpenCascade Primitives BRep-Cone eryar@163.com Abstract. BRep is short for Boundary Representation. Boundary Representation gives a complete description of an object by associating topological and geometric information for solid modeling. In this cas

OpenCascade Primitives BRep-Torus eryar@163.com Abstract. BRep is short for Boundary Representation. Boundary Representation gives a complete description of an object by associating topological and geometric information for solid modeling. In this ca

OpenCascade Primitives BRep - Sphere eryar@163.com Abstract. BRep is short for Boundary Representation. Boundary Representation gives a complete description of an object by associating topological and geometric information for solid modeling. In this

Surface Normal Vector in OpenCascade eryar@163.com 摘要Abstract:表面上某一点的法向量(Normal Vector)指的是在该点处与表面垂直的方向.对于平面,其上各点的法向是一样的,统一为这个平面的法向.对于曲面,各点具有不同的法向量.几何对象的法向量定义了它在空间中的方向,法向量是在进行光照处理时的重要参数.所以在显示造型算法离散曲面后的网格时,设置正确的法向量对场景的光照.光线追踪效果有直接影响.本文结合OpenCascade中代码,

Representation Data in OpenCascade BRep eryar@163.com 摘要Abstract:现在的显示器大多数是光栅显示器,即可以看做一个像素的矩阵.在光栅显示器上显示的任何图形,实际上都是一些具有一种或多种颜色的集合.数学上精确表示的图形在显示器中只能用逼近的方式显示出来.本文主要对OpenCascade的BRep文件中用来显示曲线和曲面的离散数据结构进行说明. 关键字:OpenCascade, BRep, Polygon, Triangulation,