834 lines
43 KiB
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834 lines
43 KiB
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<html><head><title>Topological data scripting/cn</title><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><link type='text/css' href='wiki.css' rel='stylesheet'></head><body><h1>Topological data scripting/cn</h1></div>
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<div id="mw-content-text" lang="en" dir="ltr" class="mw-content-ltr"><div class="mw-parser-output"><p>本页介绍了几种用 Python 创建和修改<a href="https://www.freecadweb.org/wiki/index.php?title=Part_Module/cn" title="Part Module/cn">零件</a>的方法。阅读之前提醒您，如果您对 python 不熟悉，最好先阅读 <a href="https://www.freecadweb.org/wiki/index.php?title=Introduction_to_Python/cn" title="Introduction to Python/cn">python 简介</a> 和 <a href="FreeCAD_Scripting_Basics.html" title="FreeCAD Scripting Basics">如何在 FreeCAD 中使用 Python 脚本</a>。
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</p><p><br />
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</p>
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<div id="toc" class="toc"><div class="toctitle"><h2>Contents</h2></div>
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<ul>
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<li class="toclevel-1 tocsection-1"><a href="#.E7.AE.80.E4.BB.8B"><span class="tocnumber">1</span> <span class="toctext">简介</span></a>
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<ul>
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<li class="toclevel-2 tocsection-2"><a href="#.E7.B1.BB.E5.9B.BE"><span class="tocnumber">1.1</span> <span class="toctext">类图</span></a></li>
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<li class="toclevel-2 tocsection-3"><a href="#.E5.87.A0.E4.BD.95.E5.BD.A2.E4.BD.93"><span class="tocnumber">1.2</span> <span class="toctext">几何形体</span></a></li>
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<li class="toclevel-2 tocsection-4"><a href="#.E6.8B.93.E6.89.91"><span class="tocnumber">1.3</span> <span class="toctext">拓扑</span></a></li>
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<li class="toclevel-2 tocsection-5"><a href="#.E7.AE.80.E5.8D.95.E4.BE.8B.E5.AD.90.EF.BC.9A.E5.88.9B.E5.BB.BA.E7.AE.80.E5.8D.95.E6.8B.93.E6.89.91.E7.BB.93.E6.9E.84"><span class="tocnumber">1.4</span> <span class="toctext">简单例子：创建简单拓扑结构</span></a>
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<ul>
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<li class="toclevel-3 tocsection-6"><a href="#.E5.88.9B.E5.BB.BA.E5.87.A0.E4.BD.95.E5.BD.A2.E4.BD.93"><span class="tocnumber">1.4.1</span> <span class="toctext">创建几何形体</span></a></li>
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<li class="toclevel-3 tocsection-7"><a href="#.E5.9C.86.E5.BC.A7"><span class="tocnumber">1.4.2</span> <span class="toctext">圆弧</span></a></li>
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<li class="toclevel-3 tocsection-8"><a href="#.E7.9B.B4.E7.BA.BF"><span class="tocnumber">1.4.3</span> <span class="toctext">直线</span></a></li>
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<li class="toclevel-3 tocsection-9"><a href="#.E6.94.BE.E7.BD.AE.E5.9C.A8.E4.B8.80.E8.B5.B7"><span class="tocnumber">1.4.4</span> <span class="toctext">放置在一起</span></a></li>
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<li class="toclevel-3 tocsection-10"><a href="#.E5.81.9A.E4.B8.AA.E6.A3.B1.E9.95.9C"><span class="tocnumber">1.4.5</span> <span class="toctext">做个棱镜</span></a></li>
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<li class="toclevel-3 tocsection-11"><a href="#.E6.98.BE.E7.A4.BA.E5.AE.83"><span class="tocnumber">1.4.6</span> <span class="toctext">显示它</span></a></li>
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</ul>
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</li>
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</ul>
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</li>
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<li class="toclevel-1 tocsection-12"><a href="#.E5.88.9B.E5.BB.BA.E5.9F.BA.E6.9C.AC.E5.9B.BE.E5.BD.A2"><span class="tocnumber">2</span> <span class="toctext">创建基本图形</span></a>
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<ul>
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<li class="toclevel-2 tocsection-13"><a href="#.E5.AF.BC.E5.85.A5.E9.9C.80.E8.A6.81.E7.9A.84.E6.A8.A1.E5.9D.97"><span class="tocnumber">2.1</span> <span class="toctext">导入需要的模块</span></a></li>
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<li class="toclevel-2 tocsection-14"><a href="#.E5.88.9B.E5.BB.BA.E5.90.91.E9.87.8F"><span class="tocnumber">2.2</span> <span class="toctext">创建向量</span></a></li>
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<li class="toclevel-2 tocsection-15"><a href="#.E5.88.9B.E5.BB.BA.E8.BE.B9"><span class="tocnumber">2.3</span> <span class="toctext">创建边</span></a></li>
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<li class="toclevel-2 tocsection-16"><a href="#.E6.98.BE.E7.A4.BA.E5.88.B0.E5.B1.8F.E5.B9.95.E4.B8.8A"><span class="tocnumber">2.4</span> <span class="toctext">显示到屏幕上</span></a></li>
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<li class="toclevel-2 tocsection-17"><a href="#.E5.88.9B.E5.BB.BA.E7.BA.BF_wire"><span class="tocnumber">2.5</span> <span class="toctext">创建线 wire</span></a></li>
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<li class="toclevel-2 tocsection-18"><a href="#.E5.88.9B.E5.BB.BA.E9.9D.A2"><span class="tocnumber">2.6</span> <span class="toctext">创建面</span></a></li>
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<li class="toclevel-2 tocsection-19"><a href="#.E5.88.9B.E5.BB.BA.E5.9C.86"><span class="tocnumber">2.7</span> <span class="toctext">创建圆</span></a></li>
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<li class="toclevel-2 tocsection-20"><a href="#.E7.94.A8.E4.B8.89.E7.82.B9.E5.88.9B.E5.BB.BA.E5.BC.A7"><span class="tocnumber">2.8</span> <span class="toctext">用三点创建弧</span></a></li>
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<li class="toclevel-2 tocsection-21"><a href="#.E5.88.9B.E5.BB.BA.E4.B8.80.E4.B8.AA.E5.A4.9A.E8.BE.B9.E5.BD.A2"><span class="tocnumber">2.9</span> <span class="toctext">创建一个多边形</span></a></li>
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<li class="toclevel-2 tocsection-22"><a href="#.E5.88.9B.E5.BB.BA.E5.B9.B3.E9.9D.A2"><span class="tocnumber">2.10</span> <span class="toctext">创建平面</span></a></li>
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<li class="toclevel-2 tocsection-23"><a href="#.E5.88.9B.E5.BB.BA.E4.B8.80.E4.B8.AA.E6.A4.AD.E5.9C.86.E5.BD.A2"><span class="tocnumber">2.11</span> <span class="toctext">创建一个椭圆形</span></a></li>
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<li class="toclevel-2 tocsection-24"><a href="#.E5.88.9B.E5.BB.BA.E4.B8.80.E4.B8.AA.E5.9C.86.E7.8E.AF"><span class="tocnumber">2.12</span> <span class="toctext">创建一个圆环</span></a></li>
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<li class="toclevel-2 tocsection-25"><a href="#.E5.88.9B.E5.BB.BA.E4.B8.80.E4.B8.AA.E7.9B.92.E5.AD.90.E6.88.96.E9.95.BF.E6.96.B9.E4.BD.93"><span class="tocnumber">2.13</span> <span class="toctext">创建一个盒子或长方体</span></a></li>
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<li class="toclevel-2 tocsection-26"><a href="#.E5.88.9B.E5.BB.BA.E4.B8.80.E4.B8.AA.E7.90.83.E4.BD.93"><span class="tocnumber">2.14</span> <span class="toctext">创建一个球体</span></a></li>
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<li class="toclevel-2 tocsection-27"><a href="#.E5.88.9B.E5.BB.BA.E5.9C.86.E6.9F.B1"><span class="tocnumber">2.15</span> <span class="toctext">创建圆柱</span></a></li>
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<li class="toclevel-2 tocsection-28"><a href="#.E5.88.9B.E5.BB.BA.E4.B8.80.E4.B8.AA.E5.9C.86.E9.94.A5"><span class="tocnumber">2.16</span> <span class="toctext">创建一个圆锥</span></a></li>
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</ul>
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</li>
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<li class="toclevel-1 tocsection-29"><a href="#.E4.BF.AE.E6.94.B9.E5.BD.A2.E7.8A.B6"><span class="tocnumber">3</span> <span class="toctext">修改形状</span></a>
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<ul>
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<li class="toclevel-2 tocsection-30"><a href="#.E8.BD.AC.E6.8D.A2.E6.93.8D.E4.BD.9C"><span class="tocnumber">3.1</span> <span class="toctext">转换操作</span></a>
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<ul>
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<li class="toclevel-3 tocsection-31"><a href="#.E5.B9.B3.E7.A7.BB.E9.9D.A2"><span class="tocnumber">3.1.1</span> <span class="toctext">平移面</span></a></li>
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<li class="toclevel-3 tocsection-32"><a href="#.E6.97.8B.E8.BD.AC.E4.B8.80.E4.B8.AA.E5.87.A0.E4.BD.95.E5.BD.A2.E7.8A.B6"><span class="tocnumber">3.1.2</span> <span class="toctext">旋转一个几何形状</span></a></li>
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<li class="toclevel-3 tocsection-33"><a href="#.E9.80.9A.E7.94.A8.E8.BD.AC.E6.8D.A2.E7.9F.A9.E9.98.B5"><span class="tocnumber">3.1.3</span> <span class="toctext">通用转换矩阵</span></a></li>
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<li class="toclevel-3 tocsection-34"><a href="#.E7.BC.A9.E6.94.BE.E5.9B.BE.E5.BD.A2"><span class="tocnumber">3.1.4</span> <span class="toctext">缩放图形</span></a></li>
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</ul>
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</li>
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<li class="toclevel-2 tocsection-35"><a href="#.E5.B8.83.E5.B0.94.E6.93.8D.E4.BD.9C"><span class="tocnumber">3.2</span> <span class="toctext">布尔操作</span></a>
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<ul>
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<li class="toclevel-3 tocsection-36"><a href="#.E6.B1.82.E5.B7.AE"><span class="tocnumber">3.2.1</span> <span class="toctext">求差</span></a></li>
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<li class="toclevel-3 tocsection-37"><a href="#.E6.B1.82.E4.BA.A4"><span class="tocnumber">3.2.2</span> <span class="toctext">求交</span></a></li>
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<li class="toclevel-3 tocsection-38"><a href="#.E6.B1.82.E5.92.8C"><span class="tocnumber">3.2.3</span> <span class="toctext">求和</span></a></li>
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<li class="toclevel-3 tocsection-39"><a href="#.E4.BA.A4.E7.BA.BF_Section"><span class="tocnumber">3.2.4</span> <span class="toctext">交线 Section</span></a></li>
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<li class="toclevel-3 tocsection-40"><a href="#.E6.8B.89.E4.BC.B8"><span class="tocnumber">3.2.5</span> <span class="toctext">拉伸</span></a></li>
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</ul>
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</li>
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</ul>
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</li>
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<li class="toclevel-1 tocsection-41"><a href="#.E6.8E.A2.E7.B4.A2.E5.BD.A2.E7.8A.B6"><span class="tocnumber">4</span> <span class="toctext">探索形状</span></a>
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<ul>
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<li class="toclevel-2 tocsection-42"><a href="#.E5.88.86.E6.9E.90.E8.BE.B9"><span class="tocnumber">4.1</span> <span class="toctext">分析边</span></a></li>
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<li class="toclevel-2 tocsection-43"><a href="#.E4.BD.BF.E7.94.A8.E9.80.89.E4.B8.AD"><span class="tocnumber">4.2</span> <span class="toctext">使用选中</span></a></li>
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</ul>
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</li>
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<li class="toclevel-1 tocsection-44"><a href="#.E5.AE.8C.E6.95.B4.E4.BE.8B.E5.AD.90.EF.BC.9AOCC_.E7.93.B6"><span class="tocnumber">5</span> <span class="toctext">完整例子：OCC 瓶</span></a>
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<ul>
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<li class="toclevel-2 tocsection-45"><a href="#.E5.AE.8C.E6.95.B4.E8.84.9A.E6.9C.AC"><span class="tocnumber">5.1</span> <span class="toctext">完整脚本</span></a></li>
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<li class="toclevel-2 tocsection-46"><a href="#.E8.AF.A6.E7.BB.86.E8.A7.A3.E9.87.8A"><span class="tocnumber">5.2</span> <span class="toctext">详细解释</span></a></li>
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</ul>
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</li>
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<li class="toclevel-1 tocsection-47"><a href="#.E8.BD.BD.E5.85.A5.E5.92.8C.E4.BF.9D.E5.AD.98"><span class="tocnumber">6</span> <span class="toctext">载入和保存</span></a></li>
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</ul>
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</div>
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<h2><span class="mw-headline" id=".E7.AE.80.E4.BB.8B">简介</span></h2>
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<p>在这里，我们将解释如何直接从 FreeCAD 的 Python 解释器，或从任何外部脚本控制 <a href="https://www.freecadweb.org/wiki/index.php?title=Part_Module/cn" title="Part Module/cn">零件</a>。如果您需要有关 Python 脚本如何在 FreeCAD 工作的更多信息，务必要浏览<a href="Scripting.html" class="mw-redirect" title="Scripting">脚本</a>部分和<a href="Scripting.html" class="mw-redirect" title="Scripting"> FreeCAD 脚本基础知识</a>页面。
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</p>
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<h3><span class="mw-headline" id=".E7.B1.BB.E5.9B.BE">类图</span></h3>
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<p>This is a <a rel="nofollow" class="external text" href="http://en.wikipedia.org/wiki/Unified_Modeling_Language">Unified Modeling Language (UML)</a> overview of the most important classes of the Part module:
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</p>
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<div class="center"><div class="floatnone"><a href="https://www.freecadweb.org/wiki/index.php?title=File:Part_Classes.jpg" class="image" title="Python classes of the Part module"><img alt="Python classes of the Part module" src="Part_Classes.jpg" width="744" height="520" /></a></div></div>
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<h3><span class="mw-headline" id=".E5.87.A0.E4.BD.95.E5.BD.A2.E4.BD.93">几何形体</span></h3>
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<p>The geometric objects are the building block of all topological objects:
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</p>
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<ul><li> <b>Geom</b> Base class of the geometric objects</li>
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<li> <b>Line</b> A straight line in 3D, defined by starting point and and point</li>
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<li> <b>Circle</b> Circle or circle segment defined by a center point and start and end point</li>
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<li> <b>......</b> And soon some more ;-)</li></ul>
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<h3><span class="mw-headline" id=".E6.8B.93.E6.89.91">拓扑</span></h3>
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<p>The following topological data types are available:
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</p>
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<ul><li> <b>Compound</b> A group of any type of topological object.</li>
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<li> <b>Compsolid</b> A composite solid is a set of solids connected by their faces. It expands the notions of WIRE and SHELL to solids.</li>
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<li> <b>Solid</b> A part of space limited by shells. It is three dimensional.</li>
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<li> <b>Shell</b> A set of faces connected by their edges. A shell can be open or closed.</li>
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<li> <b>Face</b> In 2D it is part of a plane; in 3D it is part of a surface. Its geometry is constrained (trimmed) by contours. It is two dimensional.</li>
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<li> <b>Wire</b> A set of edges connected by their vertices. It can be an open or closed contour depending on whether the edges are linked or not.</li>
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<li> <b>Edge</b> A topological element corresponding to a restrained curve. An edge is generally limited by vertices. It has one dimension.</li>
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<li> <b>Vertex</b> A topological element corresponding to a point. It has zero dimension.</li>
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<li> <b>Shape</b> A generic term covering all of the above.</li></ul>
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<h3><span class="mw-headline" id=".E7.AE.80.E5.8D.95.E4.BE.8B.E5.AD.90.EF.BC.9A.E5.88.9B.E5.BB.BA.E7.AE.80.E5.8D.95.E6.8B.93.E6.89.91.E7.BB.93.E6.9E.84">简单例子：创建简单拓扑结构</span></h3>
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<div class="floatright"><a href="https://www.freecadweb.org/wiki/index.php?title=File:Wire.png" class="image" title="Wire"><img alt="Wire" src="Wire.png" width="260" height="137" /></a></div>
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<p>We will now create a topology by constructing it out of simpler geometry.
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As a case study we use a part as seen in the picture which consists of
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four vertexes, two circles and two lines.
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</p>
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<h4><span class="mw-headline" id=".E5.88.9B.E5.BB.BA.E5.87.A0.E4.BD.95.E5.BD.A2.E4.BD.93">创建几何形体</span></h4>
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<p>First we have to create the distinct geometric parts of this wire.
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And we have to take care that the vertexes of the geometric parts
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are at the <b>same</b> position. Otherwise later on we might not be
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able to connect the geometric parts to a topology!
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</p><p>So we create first the points:
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</p>
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<pre>from FreeCAD import Base
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V1 = Base.Vector(0,10,0)
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V2 = Base.Vector(30,10,0)
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V3 = Base.Vector(30,-10,0)
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V4 = Base.Vector(0,-10,0)
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</pre>
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<h4><span class="mw-headline" id=".E5.9C.86.E5.BC.A7">圆弧</span></h4>
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<div class="floatright"><a href="https://www.freecadweb.org/wiki/index.php?title=File:Circel.png" class="image" title="Circle"><img alt="Circle" src="Circel.png" width="111" height="135" /></a></div>
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<p>To create an arc of circle we make a helper point and create the arc of
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circle through three points:
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</p>
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<pre>VC1 = Base.Vector(-10,0,0)
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C1 = Part.Arc(V1,VC1,V4)
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# and the second one
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VC2 = Base.Vector(40,0,0)
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C2 = Part.Arc(V2,VC2,V3)
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</pre>
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<h4><span class="mw-headline" id=".E7.9B.B4.E7.BA.BF">直线</span></h4>
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<div class="floatright"><a href="https://www.freecadweb.org/wiki/index.php?title=File:Line.png" class="image" title="Line"><img alt="Line" src="Line.png" width="175" height="76" /></a></div>
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<p>The line can be created very simple out of the points:
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</p>
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<pre>L1 = Part.Line(V1,V2)
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# and the second one
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L2 = Part.Line(V4,V3)
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</pre>
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<h4><span class="mw-headline" id=".E6.94.BE.E7.BD.AE.E5.9C.A8.E4.B8.80.E8.B5.B7">放置在一起</span></h4>
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<p>The last step is to put the geometric base elements together
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and bake a topological shape:
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</p>
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<pre>S1 = Part.Shape([C1,C2,L1,L2])
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</pre>
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<h4><span class="mw-headline" id=".E5.81.9A.E4.B8.AA.E6.A3.B1.E9.95.9C">做个棱镜</span></h4>
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<p>Now extrude the wire in a direction and make an actual 3D shape:
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</p>
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<pre>W = Part.Wire(S1.Edges)
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P = W.extrude(Base.Vector(0,0,10))
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</pre>
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<h4><span class="mw-headline" id=".E6.98.BE.E7.A4.BA.E5.AE.83">显示它</span></h4>
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<pre>Part.show(P)
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</pre>
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<h2><span class="mw-headline" id=".E5.88.9B.E5.BB.BA.E5.9F.BA.E6.9C.AC.E5.9B.BE.E5.BD.A2">创建基本图形</span></h2>
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<p>You can easily create basic topological objects with the "make...()"
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methods from the Part Module:
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</p>
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<pre>b = Part.makeBox(100,100,100)
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Part.show(b)
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</pre>
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<p>A couple of other make...() methods available:
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</p>
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<ul><li> <b>makeBox(l,w,h)</b>: Makes a box located in p and pointing into the direction d with the dimensions (l,w,h)</li>
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<li> <b>makeCircle(radius)</b>: Makes a circle with a given radius</li>
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<li> <b>makeCone(radius1,radius2,height)</b>: Makes a cone with a given radii and height</li>
|
||
<li> <b>makeCylinder(radius,height)</b>: Makes a cylinder with a given radius and height.</li>
|
||
<li> <b>makeLine((x1,y1,z1),(x2,y2,z2))</b>: Makes a line of two points</li>
|
||
<li> <b>makePlane(length,width)</b>: Makes a plane with length and width</li>
|
||
<li> <b>makePolygon(list)</b>: Makes a polygon of a list of points</li>
|
||
<li> <b>makeSphere(radius)</b>: Make a sphere with a given radius</li>
|
||
<li> <b>makeTorus(radius1,radius2)</b>: Makes a torus with a given radii</li></ul>
|
||
<p>See the <a href="Part_API.html" title="Part API">Part API</a> page for a complete list of available methods of the Part module.
|
||
</p>
|
||
<h4><span class="mw-headline" id=".E5.AF.BC.E5.85.A5.E9.9C.80.E8.A6.81.E7.9A.84.E6.A8.A1.E5.9D.97">导入需要的模块</span></h4>
|
||
<p>First we need to import the Part module so we can use its contents in python.
|
||
We'll also import the Base module from inside the FreeCAD module:
|
||
</p>
|
||
<pre>import Part
|
||
from FreeCAD import Base
|
||
</pre>
|
||
<h4><span class="mw-headline" id=".E5.88.9B.E5.BB.BA.E5.90.91.E9.87.8F">创建向量</span></h4>
|
||
<p><a rel="nofollow" class="external text" href="http://en.wikipedia.org/wiki/Euclidean_vector">Vectors</a> are one of the most
|
||
important pieces of information when building shapes. They contain a 3 numbers
|
||
usually (but not necessarily always) the x, y and z cartesian coordinates. You
|
||
create a vector like this:
|
||
</p>
|
||
<pre>myVector = Base.Vector(3,2,0)
|
||
</pre>
|
||
<p>We just created a vector at coordinates x=3, y=2, z=0. In the Part module,
|
||
vectors are used everywhere. Part shapes also use another kind of point
|
||
representation, called Vertex, which is acually nothing else than a container
|
||
for a vector. You access the vector of a vertex like this:
|
||
</p>
|
||
<pre>myVertex = myShape.Vertexes[0]
|
||
print myVertex.Point
|
||
> Vector (3, 2, 0)
|
||
</pre>
|
||
<h4><span class="mw-headline" id=".E5.88.9B.E5.BB.BA.E8.BE.B9">创建边</span></h4>
|
||
<p>An edge is nothing but a line with two vertexes:
|
||
</p>
|
||
<pre>edge = Part.makeLine((0,0,0), (10,0,0))
|
||
edge.Vertexes
|
||
> [<Vertex object at 01877430>, <Vertex object at 014888E0>]
|
||
</pre>
|
||
<p>Note: You can also create an edge by passing two vectors:
|
||
</p>
|
||
<pre>vec1 = Base.Vector(0,0,0)
|
||
vec2 = Base.Vector(10,0,0)
|
||
line = Part.Line(vec1,vec2)
|
||
edge = line.toShape()
|
||
</pre>
|
||
<p>You can find the length and center of an edge like this:
|
||
</p>
|
||
<pre>edge.Length
|
||
> 10.0
|
||
edge.CenterOfMass
|
||
> Vector (5, 0, 0)
|
||
</pre>
|
||
<h4><span class="mw-headline" id=".E6.98.BE.E7.A4.BA.E5.88.B0.E5.B1.8F.E5.B9.95.E4.B8.8A">显示到屏幕上</span></h4>
|
||
<p>So far we created an edge object, but it doesn't appear anywhere on screen.
|
||
This is because we just manipulated python objects here. The FreeCAD 3D scene
|
||
only displays what you tell it to display. To do that, we use this simple
|
||
method:
|
||
</p>
|
||
<pre>Part.show(edge)
|
||
</pre>
|
||
<p>An object will be created in our FreeCAD document, and our "edge" shape
|
||
will be attributed to it. Use this whenever it's time to display your
|
||
creation on screen.
|
||
</p>
|
||
<h4><span class="mw-headline" id=".E5.88.9B.E5.BB.BA.E7.BA.BF_wire">创建线 wire</span></h4>
|
||
<p>A wire is a multi-edge line and can be created from a list of edges
|
||
or even a list of wires:
|
||
</p>
|
||
<pre>edge1 = Part.makeLine((0,0,0), (10,0,0))
|
||
edge2 = Part.makeLine((10,0,0), (10,10,0))
|
||
wire1 = Part.Wire([edge1,edge2])
|
||
edge3 = Part.makeLine((10,10,0), (0,10,0))
|
||
edge4 = Part.makeLine((0,10,0), (0,0,0))
|
||
wire2 = Part.Wire([edge3,edge4])
|
||
wire3 = Part.Wire([wire1,wire2])
|
||
wire3.Edges
|
||
> [<Edge object at 016695F8>, <Edge object at 0197AED8>, <Edge object at 01828B20>, <Edge object at 0190A788>]
|
||
Part.show(wire3)
|
||
</pre>
|
||
<p>Part.show(wire3) will display the 4 edges that compose our wire. Other
|
||
useful information can be easily retrieved:
|
||
</p>
|
||
<pre>wire3.Length
|
||
> 40.0
|
||
wire3.CenterOfMass
|
||
> Vector (5, 5, 0)
|
||
wire3.isClosed()
|
||
> True
|
||
wire2.isClosed()
|
||
> False
|
||
</pre>
|
||
<h4><span class="mw-headline" id=".E5.88.9B.E5.BB.BA.E9.9D.A2">创建面</span></h4>
|
||
<p>Only faces created from closed wires will be valid. In this example, wire3
|
||
is a closed wire but wire2 is not a closed wire (see above)
|
||
</p>
|
||
<pre>face = Part.Face(wire3)
|
||
face.Area
|
||
> 99.999999999999972
|
||
face.CenterOfMass
|
||
> Vector (5, 5, 0)
|
||
face.Length
|
||
> 40.0
|
||
face.isValid()
|
||
> True
|
||
sface = Part.Face(wire2)
|
||
face.isValid()
|
||
> False
|
||
</pre>
|
||
<p>Only faces will have an area, not wires nor edges.
|
||
</p>
|
||
<h4><span class="mw-headline" id=".E5.88.9B.E5.BB.BA.E5.9C.86">创建圆</span></h4>
|
||
<p>A circle can be created as simply as this:
|
||
</p>
|
||
<pre>circle = Part.makeCircle(10)
|
||
circle.Curve
|
||
> Circle (Radius : 10, Position : (0, 0, 0), Direction : (0, 0, 1))
|
||
</pre>
|
||
<p>If you want to create it at certain position and with certain direction:
|
||
</p>
|
||
<pre>ccircle = Part.makeCircle(10, Base.Vector(10,0,0), Base.Vector(1,0,0))
|
||
ccircle.Curve
|
||
> Circle (Radius : 10, Position : (10, 0, 0), Direction : (1, 0, 0))
|
||
</pre>
|
||
<p>ccircle will be created at distance 10 from origin on x and will be facing
|
||
towards x axis. Note: makeCircle only accepts Base.Vector() for position
|
||
and normal but not tuples. You can also create part of the circle by giving
|
||
start angle and end angle as:
|
||
</p>
|
||
<pre>from math import pi
|
||
arc1 = Part.makeCircle(10, Base.Vector(0,0,0), Base.Vector(0,0,1), 0, 180)
|
||
arc2 = Part.makeCircle(10, Base.Vector(0,0,0), Base.Vector(0,0,1), 180, 360)
|
||
</pre>
|
||
<p>Both arc1 and arc2 jointly will make a circle. Angles should be provided in
|
||
degrees, if you have radians simply convert them using formula:
|
||
degrees = radians * 180/PI or using python's math module (after doing import
|
||
math, of course):
|
||
</p>
|
||
<pre>degrees = math.degrees(radians)
|
||
</pre>
|
||
<h4><span class="mw-headline" id=".E7.94.A8.E4.B8.89.E7.82.B9.E5.88.9B.E5.BB.BA.E5.BC.A7">用三点创建弧</span></h4>
|
||
<p>Unfortunately there is no makeArc function but we have Part.Arc function to
|
||
create an arc along three points. Basically it can be supposed as an arc
|
||
joining start point and end point along the middle point. Part.Arc creates
|
||
an arc object on which .toShape() has to be called to get the edge object,
|
||
the same way as when using Part.Line instead of Part.makeLine.
|
||
</p>
|
||
<pre>arc = Part.Arc(Base.Vector(0,0,0),Base.Vector(0,5,0),Base.Vector(5,5,0))
|
||
arc
|
||
> <Arc object>
|
||
arc_edge = arc.toShape()
|
||
</pre>
|
||
<p>Arc only accepts Base.Vector() for points but not tuples. arc_edge is what
|
||
we want which we can display using Part.show(arc_edge). You can also obtain
|
||
an arc by using a portion of a circle:
|
||
</p>
|
||
<pre>from math import pi
|
||
circle = Part.Circle(Base.Vector(0,0,0),Base.Vector(0,0,1),10)
|
||
arc = Part.Arc(c,0,pi)
|
||
</pre>
|
||
<p>Arcs are valid edges, like lines. So they can be used in wires too.
|
||
</p>
|
||
<h4><span class="mw-headline" id=".E5.88.9B.E5.BB.BA.E4.B8.80.E4.B8.AA.E5.A4.9A.E8.BE.B9.E5.BD.A2">创建一个多边形</span></h4>
|
||
<p>A polygon is simply a wire with multiple straight edges. The makePolygon
|
||
function takes a list of points and creates a wire along those points:
|
||
</p>
|
||
<pre>lshape_wire = Part.makePolygon([Base.Vector(0,5,0),Base.Vector(0,0,0),Base.Vector(5,0,0)])
|
||
</pre>
|
||
<h4><span class="mw-headline" id=".E5.88.9B.E5.BB.BA.E5.B9.B3.E9.9D.A2">创建平面</span></h4>
|
||
<p>A Plane is simply a flat rectangular surface. The method used to create one is
|
||
this: <b>makePlane(length,width,[start_pnt,dir_normal])</b>. By default
|
||
start_pnt = Vector(0,0,0) and dir_normal = Vector(0,0,1). Using dir_normal = Vector(0,0,1)
|
||
will create the plane facing z axis, while dir_normal = Vector(1,0,0) will create the
|
||
plane facing x axis:
|
||
</p>
|
||
<pre>plane = Part.makePlane(2,2)
|
||
plane
|
||
><Face object at 028AF990>
|
||
plane = Part.makePlane(2,2, Base.Vector(3,0,0), Base.Vector(0,1,0))
|
||
plane.BoundBox
|
||
> BoundBox (3, 0, 0, 5, 0, 2)
|
||
</pre>
|
||
<p>BoundBox is a cuboid enclosing the plane with a diagonal starting at
|
||
(3,0,0) and ending at (5,0,2). Here the BoundBox thickness in y axis is zero,
|
||
since our shape is totally flat.
|
||
</p><p>Note: makePlane only accepts Base.Vector() for start_pnt and dir_normal but not tuples
|
||
</p>
|
||
<h4><span class="mw-headline" id=".E5.88.9B.E5.BB.BA.E4.B8.80.E4.B8.AA.E6.A4.AD.E5.9C.86.E5.BD.A2">创建一个椭圆形</span></h4>
|
||
<p>To create an ellipse there are several ways:
|
||
</p>
|
||
<pre>Part.Ellipse()
|
||
</pre>
|
||
<p>Creates an ellipse with major radius 2 and minor radius 1 with the center in (0,0,0)
|
||
</p>
|
||
<pre>Part.Ellipse(Ellipse)
|
||
</pre>
|
||
<p>Create a copy of the given ellipse
|
||
</p>
|
||
<pre>Part.Ellipse(S1,S2,Center)
|
||
</pre>
|
||
<p>Creates an ellipse centered on the point Center, where the plane of the
|
||
ellipse is defined by Center, S1 and S2, its major axis is defined by
|
||
Center and S1, its major radius is the distance between Center and S1,
|
||
and its minor radius is the distance between S2 and the major axis.
|
||
</p>
|
||
<pre>Part.Ellipse(Center,MajorRadius,MinorRadius)
|
||
</pre>
|
||
<p>Creates an ellipse with major and minor radii MajorRadius and MinorRadius,
|
||
and located in the plane defined by Center and the normal (0,0,1)
|
||
</p>
|
||
<pre>eli = Part.Ellipse(Base.Vector(10,0,0),Base.Vector(0,5,0),Base.Vector(0,0,0))
|
||
Part.show(eli.toShape())
|
||
</pre>
|
||
<p>In the above code we have passed S1, S2 and center. Similarly to Arc,
|
||
Ellipse also creates an ellipse object but not edge, so we need to
|
||
convert it into edge using toShape() to display.
|
||
</p><p>Note: Arc only accepts Base.Vector() for points but not tuples
|
||
</p>
|
||
<pre>eli = Part.Ellipse(Base.Vector(0,0,0),10,5)
|
||
Part.show(eli.toShape())
|
||
</pre>
|
||
<p>for the above Ellipse constructor we have passed center, MajorRadius and MinorRadius
|
||
</p>
|
||
<h4><span class="mw-headline" id=".E5.88.9B.E5.BB.BA.E4.B8.80.E4.B8.AA.E5.9C.86.E7.8E.AF">创建一个圆环</span></h4>
|
||
<p>Using the method <b>makeTorus(radius1,radius2,[pnt,dir,angle1,angle2,angle])</b>. By
|
||
default pnt=Vector(0,0,0),dir=Vector(0,0,1),angle1=0,angle2=360 and angle=360.
|
||
Consider a torus as small circle sweeping along a big circle. Radius1 is the
|
||
radius of big cirlce, radius2 is the radius of small circle, pnt is the center
|
||
of torus and dir is the normal direction. angle1 and angle2 are angles in
|
||
radians for the small circle, the last parameter angle is to make a section of
|
||
the torus:
|
||
</p>
|
||
<pre>torus = Part.makeTorus(10, 2)
|
||
</pre>
|
||
<p>The above code will create a torus with diameter 20(radius 10) and thickness 4
|
||
(small cirlce radius 2)
|
||
</p>
|
||
<pre>tor=Part.makeTorus(10,5,Base.Vector(0,0,0),Base.Vector(0,0,1),0,180)
|
||
</pre>
|
||
<p>The above code will create a slice of the torus
|
||
</p>
|
||
<pre>tor=Part.makeTorus(10,5,Base.Vector(0,0,0),Base.Vector(0,0,1),0,360,180)
|
||
</pre>
|
||
<p>The above code will create a semi torus, only the last parameter is changed
|
||
i.e the angle and remaining angles are defaults. Giving the angle 180 will
|
||
create the torus from 0 to 180, that is, a half torus.
|
||
</p>
|
||
<h4><span class="mw-headline" id=".E5.88.9B.E5.BB.BA.E4.B8.80.E4.B8.AA.E7.9B.92.E5.AD.90.E6.88.96.E9.95.BF.E6.96.B9.E4.BD.93">创建一个盒子或长方体</span></h4>
|
||
<p>Using <b>makeBox(length,width,height,[pnt,dir])</b>.
|
||
By default pnt=Vector(0,0,0) and dir=Vector(0,0,1)
|
||
</p>
|
||
<pre>box = Part.makeBox(10,10,10)
|
||
len(box.Vertexes)
|
||
> 8
|
||
</pre>
|
||
<h4><span class="mw-headline" id=".E5.88.9B.E5.BB.BA.E4.B8.80.E4.B8.AA.E7.90.83.E4.BD.93">创建一个球体</span></h4>
|
||
<p>Using <b>makeSphere(radius,[pnt, dir, angle1,angle2,angle3])</b>. By default
|
||
pnt=Vector(0,0,0), dir=Vector(0,0,1), angle1=-90, angle2=90 and angle3=360.
|
||
angle1 and angle2 are the vertical minimum and maximum of the sphere, angle3
|
||
is the sphere diameter itself.
|
||
</p>
|
||
<pre>sphere = Part.makeSphere(10)
|
||
hemisphere = Part.makeSphere(10,Base.Vector(0,0,0),Base.Vector(0,0,1),-90,90,180)
|
||
</pre>
|
||
<h4><span class="mw-headline" id=".E5.88.9B.E5.BB.BA.E5.9C.86.E6.9F.B1">创建圆柱</span></h4>
|
||
<p>Using <b>makeCylinder(radius,height,[pnt,dir,angle])</b>. By default
|
||
pnt=Vector(0,0,0),dir=Vector(0,0,1) and angle=360
|
||
</p>
|
||
<pre>cylinder = Part.makeCylinder(5,20)
|
||
partCylinder = Part.makeCylinder(5,20,Base.Vector(20,0,0),Base.Vector(0,0,1),180)
|
||
</pre>
|
||
<h4><span class="mw-headline" id=".E5.88.9B.E5.BB.BA.E4.B8.80.E4.B8.AA.E5.9C.86.E9.94.A5">创建一个圆锥</span></h4>
|
||
<p>Using <b>makeCone(radius1,radius2,height,[pnt,dir,angle])</b>. By default
|
||
pnt=Vector(0,0,0), dir=Vector(0,0,1) and angle=360
|
||
</p>
|
||
<pre>cone = Part.makeCone(10,0,20)
|
||
semicone = Part.makeCone(10,0,20,Base.Vector(20,0,0),Base.Vector(0,0,1),180)
|
||
</pre>
|
||
<h2><span class="mw-headline" id=".E4.BF.AE.E6.94.B9.E5.BD.A2.E7.8A.B6">修改形状</span></h2>
|
||
<p>There are several ways to modify shapes. Some are simple transformation operations
|
||
such as moving or rotating shapes, other are more complex, such as unioning and
|
||
subtracting one shape from another. Be aware that
|
||
</p>
|
||
<h3><span class="mw-headline" id=".E8.BD.AC.E6.8D.A2.E6.93.8D.E4.BD.9C">转换操作</span></h3>
|
||
<h4><span class="mw-headline" id=".E5.B9.B3.E7.A7.BB.E9.9D.A2">平移面</span></h4>
|
||
<p>Translating is the act of moving a shape from one place to another.
|
||
Any shape (edge, face, cube, etc...) can be translated the same way:
|
||
</p>
|
||
<pre>myShape = Part.makeBox(2,2,2)
|
||
myShape.translate(Base.Vector(2,0,0))
|
||
</pre>
|
||
<p>This will move our shape "myShape" 2 units in the x direction.
|
||
</p>
|
||
<h4><span class="mw-headline" id=".E6.97.8B.E8.BD.AC.E4.B8.80.E4.B8.AA.E5.87.A0.E4.BD.95.E5.BD.A2.E7.8A.B6">旋转一个几何形状</span></h4>
|
||
<p>To rotate a shape, you need to specify the rotation center, the axis,
|
||
and the rotation angle:
|
||
</p>
|
||
<pre>myShape.rotate(Vector(0,0,0),Vector(0,0,1),180)
|
||
</pre>
|
||
<p>The above code will rotate the shape 180 degrees around the Z Axis.
|
||
</p>
|
||
<h4><span class="mw-headline" id=".E9.80.9A.E7.94.A8.E8.BD.AC.E6.8D.A2.E7.9F.A9.E9.98.B5">通用转换矩阵</span></h4>
|
||
<p>A matrix is a very convenient way to store transformations in the 3D
|
||
world. In a single matrix, you can set translation, rotation and scaling
|
||
values to be applied to an object. For example:
|
||
</p>
|
||
<pre>myMat = Base.Matrix()
|
||
myMat.move(Base.Vector(2,0,0))
|
||
myMat.rotateZ(math.pi/2)
|
||
</pre>
|
||
<p>Note: FreeCAD matrixes work in radians. Also, almost all matrix operations
|
||
that take a vector can also take 3 numbers, so those 2 lines do the same thing:
|
||
</p>
|
||
<pre>myMat.move(2,0,0)
|
||
myMat.move(Base.Vector(2,0,0))
|
||
</pre>
|
||
<p>When our matrix is set, we can apply it to our shape. FreeCAD provides 2
|
||
methods to do that: transformShape() and transformGeometry(). The difference
|
||
is that with the first one, you are sure that no deformations will occur (see
|
||
"scaling a shape" below). So we can apply our transformation like this:
|
||
</p>
|
||
<pre>myShape.trasformShape(myMat)
|
||
</pre>
|
||
<p>or
|
||
</p>
|
||
<pre>myShape.transformGeometry(myMat)
|
||
</pre>
|
||
<h4><span class="mw-headline" id=".E7.BC.A9.E6.94.BE.E5.9B.BE.E5.BD.A2">缩放图形</span></h4>
|
||
<p>Scaling a shape is a more dangerous operation because, unlike translation
|
||
or rotation, scaling non-uniformly (with different values for x, y and z)
|
||
can modify the structure of the shape. For example, scaling a circle with
|
||
a higher value horizontally than vertically will transform it into an
|
||
ellipse, which behaves mathematically very differenty. For scaling, we
|
||
can't use the transformShape, we must use transformGeometry():
|
||
</p>
|
||
<pre>myMat = Base.Matrix()
|
||
myMat.scale(2,1,1)
|
||
myShape=myShape.transformGeometry(myMat)
|
||
</pre>
|
||
<h3><span class="mw-headline" id=".E5.B8.83.E5.B0.94.E6.93.8D.E4.BD.9C">布尔操作</span></h3>
|
||
<h4><span class="mw-headline" id=".E6.B1.82.E5.B7.AE">求差</span></h4>
|
||
<p>Subtracting a shape from another one is called "cut" in OCC/FreeCAD jargon
|
||
and is done like this:
|
||
</p>
|
||
<pre>cylinder = Part.makeCylinder(3,10,Base.Vector(0,0,0),Base.Vector(1,0,0))
|
||
sphere = Part.makeSphere(5,Base.Vector(5,0,0))
|
||
diff = cylinder.cut(sphere)
|
||
</pre>
|
||
<h4><span class="mw-headline" id=".E6.B1.82.E4.BA.A4">求交</span></h4>
|
||
<p>The same way, the intersection between 2 shapes is called "common" and is done
|
||
this way:
|
||
</p>
|
||
<pre>cylinder1 = Part.makeCylinder(3,10,Base.Vector(0,0,0),Base.Vector(1,0,0))
|
||
cylinder2 = Part.makeCylinder(3,10,Base.Vector(5,0,-5),Base.Vector(0,0,1))
|
||
common = cylinder1.common(cylinder2)
|
||
</pre>
|
||
<h4><span class="mw-headline" id=".E6.B1.82.E5.92.8C">求和</span></h4>
|
||
<p>Union is called "fuse" and works the same way:
|
||
</p>
|
||
<pre>cylinder1 = Part.makeCylinder(3,10,Base.Vector(0,0,0),Base.Vector(1,0,0))
|
||
cylinder2 = Part.makeCylinder(3,10,Base.Vector(5,0,-5),Base.Vector(0,0,1))
|
||
fuse = cylinder1.fuse(cylinder2)
|
||
</pre>
|
||
<h4><span class="mw-headline" id=".E4.BA.A4.E7.BA.BF_Section">交线 Section</span></h4>
|
||
<p>交线是固体形体和平面的相交线。
|
||
A Section is the intersection between a solid shape and a plane shape.
|
||
It will return an intersection curve, a compound with edges
|
||
</p>
|
||
<pre>cylinder1 = Part.makeCylinder(3,10,Base.Vector(0,0,0),Base.Vector(1,0,0))
|
||
cylinder2 = Part.makeCylinder(3,10,Base.Vector(5,0,-5),Base.Vector(0,0,1))
|
||
section = cylinder1.section(cylinder2)
|
||
section.Wires
|
||
> []
|
||
section.Edges
|
||
> [<Edge object at 0D87CFE8>, <Edge object at 019564F8>, <Edge object at 0D998458>,
|
||
<Edge object at 0D86DE18>, <Edge object at 0D9B8E80>, <Edge object at 012A3640>,
|
||
<Edge object at 0D8F4BB0>]
|
||
</pre>
|
||
<h4><span class="mw-headline" id=".E6.8B.89.E4.BC.B8">拉伸</span></h4>
|
||
<p>Extrusion is the act of "pushing" a flat shape in a certain direction resulting in
|
||
a solid body. Think of a circle becoming a tube by "pushing it out":
|
||
</p>
|
||
<pre>circle = Part.makeCircle(10)
|
||
tube = circle.extrude(Base.Vector(0,0,2))
|
||
</pre>
|
||
<p>If your circle is hollow, you will obtain a hollow tube. If your circle is actually
|
||
a disc, with a filled face, you will obtain a solid cylinder:
|
||
</p>
|
||
<pre>wire = Part.Wire(circle)
|
||
disc = Part.makeFace(wire)
|
||
cylinder = disc.extrude(Base.Vector(0,0,2))
|
||
</pre>
|
||
<h2><span class="mw-headline" id=".E6.8E.A2.E7.B4.A2.E5.BD.A2.E7.8A.B6">探索形状</span></h2>
|
||
<p>You can easily explore the topological data structure:
|
||
</p>
|
||
<pre>import Part
|
||
b = Part.makeBox(100,100,100)
|
||
b.Wires
|
||
w = b.Wires[0]
|
||
w
|
||
w.Wires
|
||
w.Vertexes
|
||
Part.show(w)
|
||
w.Edges
|
||
e = w.Edges[0]
|
||
e.Vertexes
|
||
v = e.Vertexes[0]
|
||
v.Point
|
||
</pre>
|
||
<p>By typing the lines above in the python interpreter, you will gain a good
|
||
understanding of the structure of Part objects. Here, our makeBox() command
|
||
created a solid shape. This solid, like all Part solids, contains faces.
|
||
Faces always contain wires, which are lists of edges that border the face.
|
||
Each face has at least one closed wire (it can have more if the face has a hole).
|
||
In the wire, we can look at each edge separately, and inside each edge, we can
|
||
see the vertexes. Straight edges have only two vertexes, obviously.
|
||
</p>
|
||
<h3><span class="mw-headline" id=".E5.88.86.E6.9E.90.E8.BE.B9">分析边</span></h3>
|
||
<p>In case of an edge, which is an arbitrary curve, it's most likely you want to
|
||
do a discretization. In FreeCAD the edges are parametrized by their lengths.
|
||
That means you can walk an edge/curve by its length:
|
||
</p>
|
||
<pre>import Part
|
||
box = Part.makeBox(100,100,100)
|
||
anEdge = box.Edges[0]
|
||
print anEdge.Length
|
||
</pre>
|
||
<p>Now you can access a lot of properties of the edge by using the length as a
|
||
position. That means if the edge is 100mm long the start position is 0 and
|
||
the end position 100.
|
||
</p>
|
||
<pre>anEdge.tangentAt(0.0) # tangent direction at the beginning
|
||
anEdge.valueAt(0.0) # Point at the beginning
|
||
anEdge.valueAt(100.0) # Point at the end of the edge
|
||
anEdge.derivative1At(50.0) # first derivative of the curve in the middle
|
||
anEdge.derivative2At(50.0) # second derivative of the curve in the middle
|
||
anEdge.derivative3At(50.0) # third derivative of the curve in the middle
|
||
anEdge.centerOfCurvatureAt(50) # center of the curvature for that position
|
||
anEdge.curvatureAt(50.0) # the curvature
|
||
anEdge.normalAt(50) # normal vector at that position (if defined)
|
||
</pre>
|
||
<h3><span class="mw-headline" id=".E4.BD.BF.E7.94.A8.E9.80.89.E4.B8.AD">使用选中</span></h3>
|
||
<p>Here we see now how we can use the selection the user did in the viewer.
|
||
First of all we create a box and shows it in the viewer
|
||
</p>
|
||
<pre>import Part
|
||
Part.show(Part.makeBox(100,100,100))
|
||
Gui.SendMsgToActiveView("ViewFit")
|
||
</pre>
|
||
<p>Select now some faces or edges. With this script you can
|
||
iterate all selected objects and their sub elements:
|
||
</p>
|
||
<pre>for o in Gui.Selection.getSelectionEx():
|
||
print o.ObjectName
|
||
for s in o.SubElementNames:
|
||
print "name: ",s
|
||
for s in o.SubObjects:
|
||
print "object: ",s
|
||
</pre>
|
||
<p>Select some edges and this script will calculate the length:
|
||
</p>
|
||
<pre>length = 0.0
|
||
for o in Gui.Selection.getSelectionEx():
|
||
for s in o.SubObjects:
|
||
length += s.Length
|
||
print "Length of the selected edges:" ,length
|
||
</pre>
|
||
<h2><span class="mw-headline" id=".E5.AE.8C.E6.95.B4.E4.BE.8B.E5.AD.90.EF.BC.9AOCC_.E7.93.B6">完整例子：OCC 瓶</span></h2>
|
||
<p>A typical example found on the
|
||
<a rel="nofollow" class="external text" href="http://www.opencascade.org/org/gettingstarted/appli/">OpenCasCade Getting Started Page</a>
|
||
is how to build a bottle. This is a good exercise for FreeCAD too. In fact,
|
||
you can follow our example below and the OCC page simultaneously, you will
|
||
understand well how OCC structures are implemented in FreeCAD. The complete script
|
||
below is also included in FreeCAD installation (inside the Mod/Part folder) and
|
||
can be called from the python interpreter by typing:
|
||
</p>
|
||
<pre>import Part
|
||
import MakeBottle
|
||
bottle = MakeBottle.makeBottle()
|
||
Part.show(bottle)
|
||
</pre>
|
||
<h3><span class="mw-headline" id=".E5.AE.8C.E6.95.B4.E8.84.9A.E6.9C.AC">完整脚本</span></h3>
|
||
<p>Here is the complete MakeBottle script:
|
||
</p>
|
||
<pre>import Part, FreeCAD, math
|
||
from FreeCAD import Base
|
||
|
||
def makeBottle(myWidth=50.0, myHeight=70.0, myThickness=30.0):
|
||
aPnt1=Base.Vector(-myWidth/2.,0,0)
|
||
aPnt2=Base.Vector(-myWidth/2.,-myThickness/4.,0)
|
||
aPnt3=Base.Vector(0,-myThickness/2.,0)
|
||
aPnt4=Base.Vector(myWidth/2.,-myThickness/4.,0)
|
||
aPnt5=Base.Vector(myWidth/2.,0,0)
|
||
|
||
aArcOfCircle = Part.Arc(aPnt2,aPnt3,aPnt4)
|
||
aSegment1=Part.Line(aPnt1,aPnt2)
|
||
aSegment2=Part.Line(aPnt4,aPnt5)
|
||
aEdge1=aSegment1.toShape()
|
||
aEdge2=aArcOfCircle.toShape()
|
||
aEdge3=aSegment2.toShape()
|
||
aWire=Part.Wire([aEdge1,aEdge2,aEdge3])
|
||
|
||
aTrsf=Base.Matrix()
|
||
aTrsf.rotateZ(math.pi) # rotate around the z-axis
|
||
|
||
aMirroredWire=aWire.transformGeometry(aTrsf)
|
||
myWireProfile=Part.Wire([aWire,aMirroredWire])
|
||
myFaceProfile=Part.Face(myWireProfile)
|
||
aPrismVec=Base.Vector(0,0,myHeight)
|
||
myBody=myFaceProfile.extrude(aPrismVec)
|
||
myBody=myBody.makeFillet(myThickness/12.0,myBody.Edges)
|
||
neckLocation=Base.Vector(0,0,myHeight)
|
||
neckNormal=Base.Vector(0,0,1)
|
||
myNeckRadius = myThickness / 4.
|
||
myNeckHeight = myHeight / 10
|
||
myNeck = Part.makeCylinder(myNeckRadius,myNeckHeight,neckLocation,neckNormal)
|
||
myBody = myBody.fuse(myNeck)
|
||
|
||
faceToRemove = 0
|
||
zMax = -1.0
|
||
|
||
for xp in myBody.Faces:
|
||
try:
|
||
surf = xp.Surface
|
||
if type(surf) == Part.Plane:
|
||
z = surf.Position.z
|
||
if z > zMax:
|
||
zMax = z
|
||
faceToRemove = xp
|
||
except:
|
||
continue
|
||
|
||
myBody = myBody.makeThickness([faceToRemove],-myThickness/50 , 1.e-3)
|
||
|
||
return myBody
|
||
</pre>
|
||
<h3><span class="mw-headline" id=".E8.AF.A6.E7.BB.86.E8.A7.A3.E9.87.8A">详细解释</span></h3>
|
||
<pre>import Part, FreeCAD, math
|
||
from FreeCAD import Base
|
||
</pre>
|
||
<p>We will need,of course, the Part module, but also the FreeCAD.Base module,
|
||
which contains basic FreeCAD structures like vectors and matrixes.
|
||
</p>
|
||
<pre>def makeBottle(myWidth=50.0, myHeight=70.0, myThickness=30.0):
|
||
aPnt1=Base.Vector(-myWidth/2.,0,0)
|
||
aPnt2=Base.Vector(-myWidth/2.,-myThickness/4.,0)
|
||
aPnt3=Base.Vector(0,-myThickness/2.,0)
|
||
aPnt4=Base.Vector(myWidth/2.,-myThickness/4.,0)
|
||
aPnt5=Base.Vector(myWidth/2.,0,0)
|
||
</pre>
|
||
<p>Here we define our makeBottle function. This function can be called without
|
||
arguments, like we did above, in which case default values for width, height,
|
||
and thickness will be used. Then, we define a couple of points that will be used
|
||
for building our base profile.
|
||
</p>
|
||
<pre> aArcOfCircle = Part.Arc(aPnt2,aPnt3,aPnt4)
|
||
aSegment1=Part.Line(aPnt1,aPnt2)
|
||
aSegment2=Part.Line(aPnt4,aPnt5)
|
||
</pre>
|
||
<p>Here we actually define the geometry: an arc, made of 3 points, and two
|
||
line segments, made of 2 points.
|
||
</p>
|
||
<pre> aEdge1=aSegment1.toShape()
|
||
aEdge2=aArcOfCircle.toShape()
|
||
aEdge3=aSegment2.toShape()
|
||
aWire=Part.Wire([aEdge1,aEdge2,aEdge3])
|
||
</pre>
|
||
<p>Remember the difference between geometry and shapes? Here we build
|
||
shapes out of our construction geometry. 3 edges (edges can be straight
|
||
or curved), then a wire made of those three edges.
|
||
</p>
|
||
<pre> aTrsf=Base.Matrix()
|
||
aTrsf.rotateZ(math.pi) # rotate around the z-axis
|
||
aMirroredWire=aWire.transformGeometry(aTrsf)
|
||
myWireProfile=Part.Wire([aWire,aMirroredWire])
|
||
</pre>
|
||
<p>Until now we built only a half profile. Easier than building the whole profile
|
||
the same way, we can just mirror what we did, and glue both halfs together.
|
||
So we first create a matrix. A matrix is a very common way to apply transformations
|
||
to objects in the 3D world, since it can contain in one structure all basic
|
||
transformations that 3D objects can suffer (move, rotate and scale). Here,
|
||
after we create the matrix, we mirror it, and we create a copy of our wire
|
||
with that transformation matrix applied to it. We now have two wires, and
|
||
we can make a third wire out of them, since wires are actually lists of edges.
|
||
</p>
|
||
<pre> myFaceProfile=Part.Face(myWireProfile)
|
||
aPrismVec=Base.Vector(0,0,myHeight)
|
||
myBody=myFaceProfile.extrude(aPrismVec)
|
||
myBody=myBody.makeFillet(myThickness/12.0,myBody.Edges)
|
||
</pre>
|
||
<p>Now that we have a closed wire, it can be turned into a face. Once we have a face,
|
||
we can extrude it. Doing so, we actually made a solid. Then we apply a nice little
|
||
fillet to our object because we care about good design, don't we?
|
||
</p>
|
||
<pre> neckLocation=Base.Vector(0,0,myHeight)
|
||
neckNormal=Base.Vector(0,0,1)
|
||
myNeckRadius = myThickness / 4.
|
||
myNeckHeight = myHeight / 10
|
||
myNeck = Part.makeCylinder(myNeckRadius,myNeckHeight,neckLocation,neckNormal)
|
||
</pre>
|
||
<p>Then, the body of our bottle is made, we still need to create a neck. So we
|
||
make a new solid, with a cylinder.
|
||
</p>
|
||
<pre> myBody = myBody.fuse(myNeck)
|
||
</pre>
|
||
<p>The fuse operation, which in other apps is sometimes called union, is very
|
||
powerful. It will take care of gluing what needs to be glued and remove parts that
|
||
need to be removed.
|
||
</p>
|
||
<pre> return myBody
|
||
</pre>
|
||
<p>Then, we return our Part solid as the result of our function. That Part solid,
|
||
like any other Part shape, can be attributed to an object in a FreeCAD document, with:
|
||
</p>
|
||
<pre>myObject = FreeCAD.ActiveDocument.addObject("Part::Feature","myObject")
|
||
myObject.Shape = bottle
|
||
</pre>
|
||
<p>or, more simple:
|
||
</p>
|
||
<pre>Part.show(bottle)
|
||
</pre>
|
||
<h2><span class="mw-headline" id=".E8.BD.BD.E5.85.A5.E5.92.8C.E4.BF.9D.E5.AD.98">载入和保存</span></h2>
|
||
<p>There are several ways to save your work in the Part module. You can
|
||
of course save your FreeCAD document, but you can also save Part
|
||
objects directly to common CAD formats, such as BREP, IGS, STEP and STL.
|
||
</p><p>Saving a shape to a file is easy. There are exportBrep(), exportIges(),
|
||
exportStl() and exportStep() methods availables for all shape objects.
|
||
So, doing:
|
||
</p>
|
||
<pre>import Part
|
||
s = Part.makeBox(0,0,0,10,10,10)
|
||
s.exportStep("test.stp")
|
||
</pre>
|
||
<p>this will save our box into a STEP file. To load a BREP,
|
||
IGES or STEP file, simply do the contrary:
|
||
</p>
|
||
<pre>import Part
|
||
s = Part.Shape()
|
||
s.read("test.stp")
|
||
</pre>
|
||
<p>Note that importing or opening BREP, IGES or STEP files can also be done
|
||
directly from the File -> Open or File -> Import menu, while exporting
|
||
is with File -> Export
|
||
</p>
|
||
|
||
<p><br />
|
||
</p>
|
||
|
||
|
||
|
||
|
||
</div>
|
||
|
||
</div><div class="printfooter">
|
||
Online version: "<a dir="ltr" href="https://www.freecadweb.org/wiki/index.php?title=Topological_data_scripting/cn&oldid=174430">http://www.freecadweb.org/wiki/index.php?title=Topological_data_scripting/cn&oldid=174430</a>"</div>
|
||
<div id="catlinks" class="catlinks" data-mw="interface"></div><div class="visualClear"></div>
|
||
</div>
|
||
</div>
|
||
<div id="mw-navigation">
|
||
<h2>Navigation menu</h2>
|
||
|
||
</body></html> |