Draft Arc 3Points/zh-cn

底图圆形

底图绘弧

底图模块

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

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。

A Draft Arc is in fact a Draft Circle with a 数据First Angle that is not the same as its 数据Last Angle.

根据圆周上的3个点而定义的弧

如何使用

See also: Draft Tray, Draft Snap and Draft Constrain.

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

The single character keyboard shortcuts available in the task panel can be changed. See Draft Preferences. The shortcuts mentioned here are the default shortcuts.

• To manually enter coordinates enter the X, Y and Z component, and press Enter after each. Or you can press the Enter point button when you have the desired values. It is advisable to move the pointer out of the 3D view before entering coordinates.
• Press R or click the Relative checkbox to toggle relative mode. If relative mode is on, coordinates are relative to the last point, if available, else they are relative to the coordinate system origin.
• Press G or click the Global checkbox to toggle global mode. If global mode is on, coordinates are relative to the global coordinate system, else they are relative to the working plane coordinate system. introduced in version 0.20
• Press T or click the Continue checkbox to toggle continue mode. If continue mode is on, the command will restart after finishing, allowing you to continue creating arcs. introduced in version 0.20
• Press S to switch Draft snapping on or off.
• Press Esc or the Close button to abort the command.

Notes

• A Draft Arc can be edited with the Draft Edit command.

Preferences

See also: Preferences Editor and Draft Preferences.

• To change the number of decimals used for the input of coordinates: Edit → Preferences... → General → Units → Units settings → Number of decimals.
• If the Edit → Preferences... → Draft → General settings → Draft tools options → Use Part Primitives when available option is checked, the command will create a non-editable Part Feature instead of a Draft Circle.

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: Autogenerated API documentation and FreeCAD Scripting Basics.

To create a Draft Arc by 3 points use the make_arc_3points method of the Draft module:

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 EditAttachment 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 Draft

doc = App.newDocument()

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

arc = Draft.make_arc_3points(points)

doc.recompute()

Arc

Circle

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

---

• 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

---

• 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

---

• Help: Tutorials, Video tutorials
• Workbenches: Std Base, Arch, Assembly, CAM, Draft, FEM, Inspection, Mesh, OpenSCAD, Part, PartDesign, Points, Reverse Engineering, Robot, Sketcher, Spreadsheet, Start, Surface, TechDraw, Test Framework, Web

---

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

---

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