Sketcher CreateEllipseByCenter/zh-cn: Difference between revisions

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(Updating to match new version of source page)
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<languages/>
<languages/>
{{Docnav
{{Docnav|[[Sketcher_CompCreateConic|Create a conic]]|[[Sketcher CreateEllipseBy3Points|Ellipse by 3 points]]|[[Sketcher_Workbench|Sketcher]]|IconL=Sketcher_Conics.png|IconC=Workbench_Sketcher.svg|IconR=Sketcher_CreateEllipse_3points.png}}
|[[Sketcher_CompCreateConic|Create a conic]]
|[[Sketcher CreateEllipseBy3Points|Ellipse by 3 points]]
|[[Sketcher_Workbench|Sketcher]]
|IconL=Sketcher_Conics.png
|IconC=Workbench_Sketcher.svg
|IconR=Sketcher_CreateEllipse_3points.png
}}


{{GuiCommand
{{GuiCommand
|Name=Sketcher CreateEllipseByCenter
|Name=Sketcher CreateEllipseByCenter
|Workbenches=[[Sketcher Workbench|Sketcher]]
|Workbenches=[[Sketcher_Workbench|Sketcher]]
|MenuLocation=Sketch → Sketcher geometries → Create ellipse by center
|MenuLocation=Sketch → Sketcher geometries → Create ellipse by center
|Version=0.15
|Version=0.15
|SeeAlso=[[Sketcher_CreateEllipseBy3Points|Sketcher Ellipse by 3 Points]], [[Sketcher CreateCircle|Sketcher Circle]], [[Sketcher_CreateArcOfEllipse|Sketcher Arc of Ellipse]]
|SeeAlso=[[Sketcher_CreateEllipseBy3Points|Sketcher Ellipse by 3 Points]], [[Sketcher_CreateCircle|Sketcher Circle]], [[Sketcher_CreateArcOfEllipse|Sketcher Arc of Ellipse]]
}}
}}


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* 通过拖动边来移动椭圆与移动椭圆的中点效果相同。
* 通过拖动边来移动椭圆与移动椭圆的中点效果相同。


{{Docnav
{{Docnav|[[Sketcher_CompCreateConic|Create a conic]]|[[Sketcher CreateEllipseBy3Points|Ellipse by 3 points]]|[[Sketcher_Workbench|Sketcher]]|IconL=Sketcher_Conics.png|IconC=Workbench_Sketcher.svg|IconR=Sketcher_CreateEllipse_3points.png}}
|[[Sketcher_CompCreateConic|Create a conic]]
|[[Sketcher CreateEllipseBy3Points|Ellipse by 3 points]]
|[[Sketcher_Workbench|Sketcher]]
|IconL=Sketcher_Conics.png
|IconC=Workbench_Sketcher.svg
|IconR=Sketcher_CreateEllipse_3points.png
}}


{{Sketcher Tools navi{{#translation:}}}}
{{Sketcher Tools navi{{#translation:}}}}

Revision as of 20:04, 29 September 2020

Sketcher CreateEllipseByCenter

Menu location
Sketch → Sketcher geometries → Create ellipse by center
Workbenches
Sketcher
Default shortcut
None
Introduced in version
0.15
See also
Sketcher Ellipse by 3 Points, Sketcher Circle, Sketcher Arc of Ellipse

描述

本工具会根据用户拾取的三个点:中点、长半轴点与短半轴点来绘制一个椭圆。 在开启此工具时,鼠标指针会变为一个附有红色椭圆图标的白色十字。同时还会将当前的指针坐标实时显现在侧。

绘制椭圆所选中的一系列点以带数字的黄色箭头表示。C为中点,a - 长轴,b - 短轴,F1、F2为焦点。

The sequence of clicks is indicated by yellow arrows with numbers. C is the center, a - major diameter, b - minor diameter, F1, F2 are foci.

如何使用

  • 通过点击工具按钮,选择对应菜单项或借助键盘快捷键(首先需要在Interface Customization中为之分配快捷键)来调用对应绘制椭圆命令。
  • 在3D视图中第一次点击所设置的是椭圆的中心。第二次点击所设置的是椭圆的第一个半径及其方向。第三次点击所设置的是另一种半径(前两次点击所定义的直线至第三次点击位置的距离即为第二个半径)。
  • 第三次点击后,椭圆就创建好了,与之共存的还有一系列对齐于它的构造几何对象(长轴、短轴、两个焦点)如果不需要这些构造几何对象,可将其手动删除,以后还可以重新创建。参见内部对齐约束在构图工作台中显示隐藏的内部几何图形
  • ESC键或单击鼠标右键来退出此功能。

特性

  • 长轴与短轴是严格界定的,调整椭圆时并不能交换两者。这是求解器参数化椭圆时所用的信息(中点(x,y)、焦点focus1(x,y)以及短半轴长度(b)),OpenCascade也严格遵循相同的行为。因此,必须通过旋转的方式来交换椭圆的两轴。
  • 当椭圆的长轴与短轴被删,且焦点之一被约束为与中点重合,则该椭圆将变为一个圆。但是此圆中的半径约束却无法生效。
  • 通过拖动边来移动椭圆与移动椭圆的中点效果相同。