# eryar

PipeCAD - Plant Piping Design Software.
RvmTranslator - Translate AVEVA RVM to OBJ, glTF, etc.
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## 11 2014 档案

摘要: 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 to a meeting of the Irish Academy, and Hamilton was so pleased with his discovery that he scratched the fundamental formula of quaternion algebra. There are several different ways we can express orientation and angular displacement in 3D. Here we discuss the three most important methods  阅读全文

posted @ 2014-11-29 19:18 eryar 阅读(3735) | 评论 (0)  编辑 |

posted @ 2014-11-29 15:14 eryar 阅读(2368) | 评论 (0)  编辑 |

摘要: 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 the direction of extrusion and defined by a unit vector). The u parameter is along the extruded curve. The v parameter is along the direction of extrusion. The form of a surface of linear extrusion is generally a ruled surface. It can be a cylindrical surface, or a planar surface.

Key Words.  阅读全文

posted @ 2014-11-23 16:46 eryar 阅读(3071) | 评论 (0)  编辑 |

摘要: 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 code, you will learn these.

Key Words. OpenCASCADE, Sphere, BRep  阅读全文

posted @ 2014-11-22 17:52 eryar 阅读(2219) | 评论 (0)  编辑 |

摘要: Abstract. By making a simple box to demonstrate the BRep data structure of the OpenCASCADE. The construction method is different from BRepPrimAPI_MakeBox. In the paper construct the box from vertex, edge to solid, while in BRepPrimAPI_MakeBox from solid, shell to vertex. From the construction, the BRep data structure in OpenCASCADE also can be called the Winged-Edge data structure.

Key Words. OpenCASCADE, BRep, Box, The Winged-Edge Structure  阅读全文

posted @ 2014-11-16 22:22 eryar 阅读(4270) | 评论 (0)  编辑 |

Updating……
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posted @ 2014-11-16 20:59 eryar 阅读(32448) | 评论 (0)  编辑 |

摘要: 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/edge/vertex to keep track all information in the solid model. The winged-edge data structure uses edges to keep track all information in the solid model. The paper focus on the BRep of OpenCASCADE and OpenNURBS.

Key Words. OpenCASCADE, BRep, OpenNURBS, The Winged-edge Structure,  阅读全文

posted @ 2014-11-08 11:48 eryar 阅读(6596) | 评论 (0)  编辑 |

摘要: Abstract. The openNURBS Toolkit consists of C++ source code for a library that will read and write a openNURBS 3D model file(.3dm). More than 400 software development teams and applications including Rhinoceros, exchange 3-D models using the openNURBS (.3dm) file format. But there is no a simple viwer for 3dm on PC except Rhinoceros. So I want to develop a 3DM viewer based on OpenSceneGraph to visualize the 3DM file.

Key Words. OpenNURBS, 3DM Viewer, OpenSceneGraph  阅读全文

posted @ 2014-11-04 21:34 eryar 阅读(4769) | 评论 (0)  编辑 |

摘要: Abstract. The OpenNURBS initiative provides CAD/CAM/CAE and computer graphics software developers the tools to accurately transfer 3D geometry between applications. The OpenNURBS C++ source code is clean and fairly simple. The OpenNURBS Toolkit is intended for use by C++ and .NET programmers. The toolkit includes complete source code to create a library that will read and write 3dm files. OpenCASCADE providing services for 3D surface and solid modeling, CAD data exchange, and visulization. Most   阅读全文

posted @ 2014-11-01 10:17 eryar 阅读(5168) | 评论 (0)  编辑 |