Draft Arc 3Points/zh-cn

底图圆形

底图绘弧

底图模块

Draft Arc 3Points
Menu location
Draft → Arc 3 points
Workbenches
Draft, Arch
Default shortcut
A T
Introduced in version
0.19
See also
Draft Arc, Draft Circle, Draft Ellipse

描述

底图三圆周点绘弧工具通过输入4个点：中点、半径、第一个点、最后一点，或拾取的切线，或上述若干组合，在当前的工作平面上创建一条圆弧。它将根据Draft Tray中的Draft Linestyle设置来创建对应圆弧。

除了添加起始角度与终止角度这两个参数之外，本工具的工作方式与底图圆形工具相同。要绘制椭圆弧，可借助底图椭圆工具。另外，您也可以通过底图B样条与底图贝叶斯曲线工具来近似地逼近一条圆弧。

根据圆周上的3个点而定义的弧

如何使用

1. 按下 Draft Arc 3Points按钮，或先按A键再按T键。
2. 在3D视图中点击第一个点，或输入一个 坐标并按下 add point按钮。
3. 在3D视图中点击第二个点，或输入一个半径值。
4. 在3D视图中点击第三个点，或输入一个起始角度。

选项

• Press X, Y or Z after one point to constrain the following point on the given axis.
• To enter coordinates manually, simply enter the numbers, then press Enter between each X, Y and Z component.
  • You can press the add point button when you have entered the desired values to insert the point.
• Press R or click the checkbox to toggle relative mode. If relative mode is on, the coordinates of the following point are relative to the previous one; if not, they are absolute, taken from the origin (0, 0, 0).
• Hold Shift while drawing to constrain your next point horizontally or vertically in relation to the previous one.
• Press Esc or the Close button to abort the current command.

属性

属性

弧对象享有Draft Circle中的所有属性，但是有些属性仅对圆形而言才有意义。

脚本

参见: Draft API 与 FreeCAD Scripting Basics。

See also: Draft API and FreeCAD Scripting Basics.

The Arc by 3 points tool can be used in macros and from the Python console by using the following function:

arc = make_arc_3points(points, placement=None, face=False, support=None, map_mode="Deactivated", primitive=False)

• Creates an arc object from the given points list.
• If a placement is given, the center of the circular arc will be moved to this place. See Placement for more information.
• If face is True, the arc will make a face, that is, it will appear filled.
• If support is given, it is a LinkSubList, that is, a list indicating an object, and a subelement of that object. This is used so that the object appears referenced to this support.

For example, support=[(obj, ("Face1"))]

• If map_mode is given, it is a string defining a type of mapping, for example, map_mode='FlatFace', map_mode='ThreePointsPlane', etc. See Part Attachment for more information.
• If primitive is True, the arc created will be a simple Part Feature, not a complex Draft object.

Example:

import FreeCAD as App
import draftobjects.arc_3points as arc3

doc = App.newDocument()
points = [App.Vector(0, 0, 0),
          App.Vector(5, 10, 0),
          App.Vector(10, 0, 0)]

arc = arc3.make_arc_3points(points)

doc.recompute()

Note: internally this function still uses Draft.makeCircle, so the object created is the same as the one created by Circle and Arc.

Arc

Ellipse

Draft

Draft

• Drafting: Line, Polyline, Fillet, Arc, Arc by 3 points, Circle, Ellipse, Rectangle, Polygon, B-spline, Cubic Bézier curve, Bézier curve, Point, Facebinder, ShapeString, Hatch
• Annotation: Text, Dimension, Label, Annotation styles, Annotation scale
• Modification: Move, Rotate, Scale, Mirror, Offset, Trimex, Stretch, Clone, Array, Polar array, Circular array, Path array, Path link array, Point array, Point link array, Edit, Subelement highlight, Join, Split, Upgrade, Downgrade, Wire to B-spline, Draft to sketch, Set slope, Flip dimension, Shape 2D view

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• Draft Tray: Select plane, Set style, Toggle construction mode, AutoGroup
• Snapping: Snap lock, Snap endpoint, Snap midpoint, Snap center, Snap angle, Snap intersection, Snap perpendicular, Snap extension, Snap parallel, Snap special, Snap near, Snap ortho, Snap grid, Snap working plane, Snap dimensions, Toggle grid

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• Miscellaneous: Apply current style, Layer, Manage layers, Add a new named group, Move to group, Select group, Add to construction group, Toggle normal/wireframe display, Create working plane proxy, Heal, Show snap toolbar
• Additional: Constraining, Pattern, Preferences, Import Export Preferences, DXF/DWG, SVG, OCA, DAT
• Context menu:
  • Layer container: Merge layer duplicates, Add new layer
  • Layer: Activate this layer, Select layer contents
  • Text: Open hyperlinks
  • Wire: Flatten
  • Working plane proxy: Write camera position, Write objects state

User documentation

• Getting started
• Installation: Download, Windows, Linux, Mac, Additional components, Docker, AppImage, Ubuntu Snap
• Basics: About FreeCAD, Interface, Mouse navigation, Selection methods, Object name, Preferences, Workbenches, Document structure, Properties, Help FreeCAD, Donate

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• Addons: Addon Manager, External workbenches, Scripting and macros

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• Hubs: User hub, Power users hub, Developer hub