OpenCASCADE General Transformation

OpenCASCADE General Transformation eryar@163.com Abstract. OpenCASCADE provides a general transformation class: gp_GTrsf. It can be a transformation from gp, an affinity, or you can define your own transformation giving the matrix of transformation.…

(zhuan) Attention in Neural Networks and How to Use It

Adam Kosiorek About Attention in Neural Networks and How to Use It this blog comes from: http://akosiorek.github.io/ml/2017/10/14/visual-attention.html Oct 14, 2017 Attention mechanisms in neural networks, otherwise known as neural attention or just…

OpenCASCADE AIS Manipulator

OpenCASCADE AIS Manipulator eryar@163.com Abstract. OpenCASCADE7.1.0 introduces new built-in interactive object AIS_Manipulator providing interface for moving objects within 3D viewer. The class features three kinds of transformation modes for attach…

OpenCASCADE Shape Location

OpenCASCADE Shape Location eryar@163.com Abstract. The TopLoc package of OpenCASCADE gives resources to handle 3D local coordinate systems called Locations. A Location is a composition of elementary coordinate systems, each one is called a Datum. The…

OpenCASCADE Ring Type Spring Modeling

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…

A Simple OpenCASCADE Qt Demo-occQt

A Simple OpenCASCADE Qt Demo-occQt eryar@163.com Abstract. OpenCASCADE have provided the Qt samples in the samples directory, but they are a little complicated. So I decide write a simple OpenCASCADE Qt demo for the OpenCASCADE beginners. Key Words.…

OpenCASCADE View Manipulator

OpenCASCADE View Manipulator eryar@163.com Abstract. When you finish modeling objects in the scene, you must want to use some operations to view the scene objects, such as Pan, Zoom and Rotate the scene. Pan and Zoom is easy to understand, rotate the…

OpenCASCADE Coordinate Transforms

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 Camera

OpenCASCADE Camera eryar@163.com Abstract. OpenCASCADE introduce a new class Graphic3d_Camera for the Visualization module. The camera class provides object-oriented approach to setting up projection and orientation properties of 3D view. The paper u…

OpenCASCADE Quaternion

OpenCASCADE Quaternion eryar@163.com Abstract. The quaternions are members of a noncommutative division algebra first invented by William Rowan Hamilton. The idea for quaternions occurred to him while he was walking along the Royal Cannal on his way…

OpenCASCADE Linear Extrusion Surface

OpenCASCADE Linear Extrusion Surface eryar@163.com Abstract. OpenCASCADE linear extrusion surface is a generalized cylinder. Such a surface is obtained by sweeping a curve (called the “extruded curve” or “basis”) in a given direction (referred to as…

Mesh Data Structure in OpenCascade

Mesh Data Structure in OpenCascade eryar@163.com 摘要Abstract:本文对网格数据结构作简要介绍,并结合使用OpenCascade中的数据结构,将网格数据在OpenSceneGraph中可视化. 关键字KeyWords:OpenCascade.OpenSceneGraph.Triangulation.Mesh Data Structure 一.引言 Introduction 三角网格就是全部由三角形组成的多边形网格.多边形和三角网格在图形学和建…

Package gp in the OpenCASCADE

Package gp in the OpenCASCADE eryar@163.com China 一.简介 Introduction to Package gp 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…

Topology Shapes of OpenCascade BRep

Topology Shapes of OpenCascade BRep eryar@163.com 摘要Abstract:通过对OpenCascade中的BRep数据的读写,理解边界表示法的概念及实现.理解了拓朴形状的数据结构,就对ModelingData模块有了清晰认识,方便OpenCascade其他模块如ModelingAlgorithms和Visiualization模块的理解. 关键字Key Words:OpenCascade, BRep, Topology, BRep Format 一…

OpenCascade Shape Representation in OpenSceneGraph

OpenCascade Shape Representation in OpenSceneGraph eryar@163.com 摘要Abstract:本文通过程序实例,将OpenCascade中的拓朴数据(边.面)离散化后在OpenSceneGraph中进行显示.有了这些离散数据,就可以不用OpenCascade的显示模块了,可以使用其他显示引擎对形状进行显示.即若要线框模式显示形状时,就绘制离散形状拓朴边后得到的多段线:若要实体渲染模式显示形状时,就绘制离散形状拓朴面得到的三角网格.理解这些…

Locations Section of OpenCascade BRep

Locations Section of OpenCascade BRep eryar@163.com 摘要Abstract:本文结合OpenCascade的BRep格式描述文档和源程序,对BRep格式进行分析,详细说明BRep的数据组织形式.本文主要通过对BRep文件中的Locations部分的读写代码进行分析,来完全理解OpenCascade中的Location部分. 关键字Key Words:OpenCascade, BRep Format, Location, Location Set…

OpenCASCADE 基础

OpenCASCADE 基础转载▼ 一直在用OCC作项目,但这方面的中文资料很少,看来OCC在中国还不是十分普及: 后来,项目中使用OCC和DirectX结合使用,取得了很好的效果: 随着OCC6.3版本的推出,Open CASCADE在速度方面已有了很大的改变.以下为一些OCC的基础知识,愿与各位OCC爱好者共同学习: 一:OCC中的基础类: gp_Pnt 在OCC中,gp_Pnt表示一个顶点,gp_Vec表示一个向量,可以用两个顶点来生成一个向量. 比如: gp_Pnt P1(0,0,0)…

OpenCASCADE Texture Mapping

OpenCASCADE Texture Mapping eryar@163.com Abstract. 纹理贴图技术的出现和流行是图形显示技术的一个非常重要的里程碑,直接影响3D技术从工业进入娱乐领域.本文结合OpenCASCADE中纹理贴图的源码,来说明纹理贴图在OpenCASCADE中实现. Key Words. OpenCASCADE 纹理贴图, Texture Mapping 1.Introduction 纹理贴图技术的出现和流行是图形显示技术的一个非常重要的里程碑,直接影响了3D技术从…

Stateful Future Transformation

As an async programming pattern, Future has been popular with many of our programmers across a wide range of languages. Loosely speaking, Future is a wrapper around a value which will be available at some point in the future. Strictly speaking, Futur…

OpenCASCADE 包说明

转载地址:http://www.cppblog.com/eryar/archive/2012/06/30/180916.html 一.简介 Introduction to Package gp 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)…

OpenCascade拓扑对象之：拓扑对象方向继承关系

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Convert BSpline Curve to Arc Spline in OpenCASCADE

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…

OpenCASCADE BRep Projection

OpenCASCADE BRep Projection eryar@163.com 一网友发邮件问我下图所示的效果如何在OpenCASCADE中实现,我的想法是先构造出螺旋线,再将螺旋线投影到面上. 为了验证我的想法,结合原来螺旋线的造型算法,来测试下这种效果的实现.依然采用Tcl脚本在Draw Test Harness中试验.个人觉得高效使用OpenCASCADE的方法应该也是先用Tcl脚本来验证一些想法后,再根据使用到的命令找到OpenCASCADE中DRAW的命令实现,最后再可以根据DRA…

OpenCASCADE Expression Interpreter by Flex & Bison

OpenCASCADE Expression Interpreter by Flex & Bison eryar@163.com Abstract. OpenCASCADE provide data structure of any expression, relation or function used in mathematics. Flex and Bison are tools for building programs that handle structured input. Th…

OpenCASCADE Data Exchange - 3D PDF

OpenCASCADE Data Exchange - 3D PDF eryar@163.com Abstract. Today most 3D engineering model data are save to 3D PDF files. Universal 3D(U3D) along side Product Representation Compact(PRC), U3D is the historical foundation used to embed 3D interactive…

OpenCASCADE Interpolations and Approximations

OpenCASCADE Interpolations and Approximations eryar@163.com Abstract. In modeling, it is often required to approximate or interpolate points to curves and surfaces. In interpolation, the process is complete when the curve or surface passes through al…