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<languages/>
{{GuiCommand|Name=Draft BezCurve|Workbenches=[[Draft Module|Draft]], [[Arch Module|Arch]]|MenuLocation=Draft -> BezCurve|Shortcut=B Z}}

{{Docnav
|[[Draft_CubicBezCurve|CubicBezCurve]]
|[[Draft_Point|Point]]
|[[Draft_Workbench|Draft]]
|IconL=Draft_CubicBezCurve.svg
|IconR=Draft_Point.svg
|IconC=Workbench_Draft.svg
}}

{{GuiCommand
|Name=Draft BezCurve
|MenuLocation=Drafting → Bézier tools → Bézier curve
|Workbenches=[[Draft_Workbench|Draft]], [[Arch_Workbench|Arch]]
|Shortcut={{KEY|B}} {{KEY|Z}}
|Version=0.14
|SeeAlso=[[Draft_CubicBezCurve|Draft CubicBezCurve]], [[Draft_BSpline|Draft BSpline]]
}}

==Description==
==Description==


The [[Image:Draft_BezCurve.svg|24px]] '''Draft BezCurve''' command creates a [http://en.wikipedia.org/wiki/Bezier_curve Bézier curve] from several points.


The command creates a single Bézier curve with a {{PropertyData|Degree}} that is {{incode|number_of_points - 1}}. It can be transformed into a piecewise Bézier curve by reducing this property.
The BezCurve tool creates a [http://en.wikipedia.org/wiki/Bezier_curve Bezier Curve] (or a piecewise Bezier Curve) from several points in the current [[Draft Workingplane|work plane]]. It takes the [[Draft Linestyle|linewidth and color]] previously set on the Tasks tab.


The Draft BezCurve and the [[Draft_CubicBezCurve|Draft CubicBezCurve]] commands use {{Emphasis|control points}} to define the position and curvature of the spline. The [[Draft BSpline|Draft BSpline]] command, on the other hand, specifies the {{Emphasis|exact points}} through which the curve will pass.
The object is created as a single Bezier Curve of degree (number_of_points - 1). This can be changed to a piecewise Bezier Curve of a specified degree after creation using the [[Property|properties editor]]. Bezier Curves can be edited using {{KEY|[[Image:Draft Edit.png|16px]] [[Draft Edit]]}}.


[[Image:Draft_BezCurve_Example.png|400px]]
[[Image:Draft_BezCurve_Example.png|400px]]
{{Caption|Bézier curve defined by multiple points}}
==How to use==

==Usage==

See also: [[Draft_Tray|Draft Tray]], [[Draft_Snap|Draft Snap]] and [[Draft_Constrain|Draft Constrain]].

# There are several ways to invoke the command:
#* Press the {{Button|[[Image:Draft_BezCurve.svg|16px]] [[Draft_BezCurve|Bézier curve]]}} button.
#* Select the {{MenuCommand|Drafting → Bézier tools → [[Image:Draft_BezCurve.svg|16px]] Bézier curve}} option from the menu.
#* Use the keyboard shortcut: {{KEY|B}} then {{KEY|Z}}. {{Version|0.20}}
# The {{MenuCommand|Bézier curve}} task panel opens. See [[#Options|Options]] for more information.
# Pick the first point in the [[3D_view|3D view]], or type coordinates and press the {{Button|[[Image:Draft_AddPoint.svg|16px]] Enter point}} button.
# Pick additional points in the [[3D_view|3D view]], or type coordinates and press the {{Button|[[Image:Draft_AddPoint.svg|16px]] Enter point}} button.
# Press {{KEY|Esc}} or the {{Button|Close}} button to finish the command.


# Press the {{KEY|[[Image:Draft_BezCurve.png|16px]] [[Draft BezCurve]]}} button, or press {{KEY|B}} then {{KEY|Z}} keys.
# Click a first point on the 3D view, or type a [[Draft_Coordinates|coordinate]]
# Click additional point on the 3D view, or type a [[Draft_Coordinates|coordinate]]
# Press {{KEY|F}} or {{KEY|C}}, or double-click the last point, or click on the first point to finish and close the curve.
==Options==
==Options==


The single character keyboard shortcuts available in the task panel can be changed. See [[Draft_Preferences|Draft Preferences]]. The shortcuts mentioned here are the default shortcuts (for version 0.22).
* Press {{KEY|F}} or the {{KEY|[[Image:Draft FinishLine.png|12px]] '''[[Draft_FinishLine|Finish]]'''}} button to finish the spline, leaving it open

* Press {{KEY|C}} or the {{KEY|[[Image:Draft CloseLine.png|12px]] '''[[Draft_CloseLine|Close]]'''}} button or click on the first point to finish the spline, but making it closed by adding a last segment between the last point and the first one.
* To manually enter coordinates enter the X, Y and Z component, and press {{KEY|Enter}} after each. Or you can press the {{Button|[[Image:Draft_AddPoint.svg|16px]] Enter point}} button when you have the desired values. It is advisable to move the pointer out of the [[3D_view|3D view]] before entering coordinates.
* Press {{KEY|X}}, {{KEY|Y}} or {{KEY|Z}} after a point to constrain the next point on the given axis.
* Press {{KEY|R}} or click the {{MenuCommand|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.
* To enter coordinates manually, simply enter the numbers, then press {{KEY|ENTER}} between each X, Y and Z component.
* Press {{KEY|R}} or click the checkbox to check/uncheck the {{KEY|'''Relative'''}} button. If relative mode is on, the coordinates of the next point are relative to the last one. If not, they are absolute, taken from the (0,0,0) origin point.
* Press {{KEY|G}} or click the {{MenuCommand|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 [[Draft_SelectPlane|working plane]] coordinate system. {{Version|0.20}}
* Press {{KEY|F}} or click the {{MenuCommand|Filled}} checkbox to toggle filled mode. If filled mode is on, the created curve will have {{PropertyData|Make Face}} set to {{TRUE}} and will have a filled face, provided it is closed and does not self-intersect. Note that a self-intersecting curve with a face will not display properly, for such a curve {{PropertyData|Make Face}} must be set to {{FALSE}}.
* Press {{KEY|T}} or click the checkbox to check/uncheck the {{KEY|'''Continue'''}} button. If continue mode is on, the BezCurve tool will restart after you finish or close it, allowing you to draw another one without pressing the BezCurve button again.
* Press {{KEY|N}} or click the {{MenuCommand|Continue}} checkbox to toggle continue mode. If continue mode is on, the command will restart after using {{Button|[[Image:Draft_FinishLine.svg|16px]] Finish}} or {{Button|[[Image:Draft_CloseLine.svg|16px]] Close}}, or after creating a closed curve by snapping to the first point of the curve, allowing you to continue creating curves.
* Press {{KEY|CTRL}} while drawing to force [[Draft_Snap|snapping]] your point to the nearest snap location, independently of the distance.
* Press {{KEY|SHIFT}} while drawing to [[Draft_Constrain|constrain]] your next point horizontally or vertically in relation to the last one.
* Press {{KEY|/}} or the {{Button|[[Image:Draft_UndoLine.svg|16px]] Undo}} button to undo the last point.
* Press {{KEY|W}} or press the {{KEY|[[Image:Draft Wipe.png|12px]] '''Wipe'''}} button to remove the existing segments and start the spline from the last point.
* Press {{KEY|A}} or the {{Button|[[Image:Draft_FinishLine.svg|16px]] Finish}} button to finish the command and leave the curve open.
* Press {{KEY|CTRL}}+{{KEY|Z}} or press the {{KEY|[[Image:Draft UndoLine.png|12px]] '''[[Draft_UndoLine|Undo]]'''}} button to undo the last point.
* Press {{KEY|O}} or the {{Button|[[Image:Draft_CloseLine.svg|16px]] Close}} button to finish the command and close the curve. A closed curve can also be created by snapping to the first point of the curve.
* Press {{KEY|ESC}} or the {{KEY|'''Cancel'''}} button to abort the current BezCurve command.
* Press {{KEY|W}} or the {{Button|[[Image:Draft Wipe.svg|16px]] Wipe}} button to delete the segments already placed, but keep working from the last point.
* Press {{KEY|U}} or the {{Button|[[Image:Draft SelectPlane.svg|16px]] [[Draft_SelectPlane|Set WP]]}} button to adjust the current working plane in the orientation defined by the last and the previous point.
* Press {{KEY|S}} to switch [[Draft_Snap|Draft snapping]] on or off.
* Press {{KEY|Esc}} or the {{Button|Close}} button to finish the command.

==Notes==

* A Draft BezCurve can be edited with the [[Draft_Edit|Draft Edit]] command.
* OpenCascade, and therefore FreeCAD, does not support Bézier curves of degrees larger than 25. This should not be a problem in practice, as most users typically use Bézier curves of degrees 3 to 5.


==Properties==
==Properties==


See also: [[Property_editor|Property editor]].
* {{PropertyData|Closed}}: Specifies if the Bezier Curve is closed or not

* {{PropertyData|Degree}}: Specifies the degree of the Bezier Curve (or segments)
A Draft BezCurve object is derived from a [[Part_Part2DObject|Part Part2DObject]] and inherits all its properties. It also has the following additional properties:

=== Data ===

{{TitleProperty|Draft}}

* {{PropertyData|Area|Area}}: (read-only) specifies the area of the face of the curve. The value will be {{value|0.0}} if {{PropertyData|Make Face}} if {{FALSE}} or the face cannot be created.
* {{PropertyData|Closed|Bool}}: specifies if the curve is closed or not. If the curve is initially open this value is {{FALSE}}, setting it to {{TRUE}} will draw a segment to close the curve. If the curve is initially closed this value is {{TRUE}}, setting it to {{FALSE}} will remove the last segment and make the curve open.
* {{PropertyData|Continuity|IntegerList}}: (read-only) specifies the continuity of the curve.
* {{PropertyData|Degree|Integer}}: specifies the degree of the curve.
* {{PropertyData|Length|Length}}: (read-only) specifies the total length of the curve.
* {{PropertyData|Make Face|Bool}}: specifies if the curve makes a face or not. If it is {{TRUE}} a face is created, otherwise only the perimeter is considered part of the object. This property only works if {{PropertyData|Closed}} is {{TRUE}} and if the curve does not self-intersect.
* {{PropertyData|Points|VectorList}}: specifies the control points of the curve in its local coordinate system.

=== View ===

{{TitleProperty|Draft}}

* {{PropertyView|Arrow Size|Length}}: specifies the size of the symbol displayed at the end of the curve.
* {{PropertyView|Arrow Type|Enumeration}}: specifies the type of symbol displayed at the end of the curve, which can be {{value|Dot}}, {{value|Circle}}, {{value|Arrow}}, {{value|Tick}} or {{value|Tick-2}}.
* {{PropertyView|End Arrow|Bool}}: specifies whether to show a symbol at the end of the curve, so it can be used as an annotation line.
* {{PropertyView|Pattern|Enumeration}}: specifies the [[Draft_Pattern|Draft Pattern]] with which to fill the face of the closed curve. This property only works if {{PropertyData|Make Face}} is {{TRUE}} and if {{PropertyView|Display Mode}} is {{value|Flat Lines}}.
* {{PropertyView|Pattern Size|Float}}: specifies the size of the [[Draft_Pattern|Draft Pattern]].


==Scripting==
==Scripting==


See also: [https://freecad.github.io/SourceDoc/ Autogenerated API documentation] and [[FreeCAD Scripting Basics|FreeCAD Scripting Basics]].

To create a Draft Line use the {{incode|make_bezcurve}} method ({{Version|0.19}}) of the Draft module. This method replaces the deprecated {{incode|makeBezCurve}} method.


The BezCurve tool can by used in [[macros]] and from the python console by using the following function:
{{Code|code=
{{Code|code=
makeBezCurve(pointslist,[closed],[placement],[support],[degree])
bezcurve = make_bezcurve(pointslist, closed=False, placement=None, face=None, support=None, degree=None)
bezcurve = make_bezcurve(Part.Wire, closed=False, placement=None, face=None, support=None, degree=None)
}}
}}
* Create a Bezier Curve object from the given list of vectors. Instead of a pointslist, you can also pass a Part Wire.


* Creates a {{incode|bezcurve}} object with the given list of points, {{incode|pointslist}}.
Example:
** Each point in the list is defined by its {{incode|FreeCAD.Vector}}, with units in millimeters.
** Alternatively, the input can be a {{incode|Part.Wire}}, from which points are extracted.
* If {{incode|closed}} is {{incode|True}}, or if the first and last points are identical, the curve is closed.
* If {{incode|placement}} is {{incode|None}} the curve is created at the origin.
* If {{incode|face}} is {{incode|True}}, and the curve is closed, the curve will make a face, that is, it will appear filled.

Example:

{{Code|code=
{{Code|code=
import FreeCAD,Draft
import FreeCAD as App
import Draft
myFeature = Draft.makeBezCurve(Draft.makeBezCurve(points,False)

doc = App.newDocument()

p1 = App.Vector(0, 0, 0)
p2 = App.Vector(1000, 1000, 0)
p3 = App.Vector(2000, 0, 0)
p4 = App.Vector(1500, -2000, 0)

bezcurve1 = Draft.make_bezcurve([p1, p2, p3, p4], closed=True)
bezcurve2 = Draft.make_bezcurve([p4, 1.3*p2, p1, 4.1*p3], closed=True)
bezcurve3 = Draft.make_bezcurve([1.7*p3, 1.5*p4, 2.1*p2, p1], closed=True)

doc.recompute()
}}
}}
==Contraining Nodes==
The segment endpoints in a piecewise Bezier Curve can be constrained such that adjacent control points are tangent or symmetric to the segments at the endpoint. This is done after object creation using {{KEY|[[Image:Draft Edit.png|16px]] [[Draft Edit]]}}.
* [[Image:Draft_BezSharpNode.svg|32px]] '''Sharp''' - remove constraints
* [[Image:Draft_BezTanNode.svg|32px]] '''Tangent''' - force adjacent control points to be tangent
* [[Image:Draft_BezSymNode.svg|32px]] '''Symmetric''' - force adjacent control points to be tangent and equi-distant



==Limitations==
{{Docnav
* This tool is not yet generally available. It will be included in a future version. (post v0.13)
|[[Draft_CubicBezCurve|CubicBezCurve]]
* The Points Property does not yet appear in the properties list.
|[[Draft_Point|Point]]
* OpenCascade does not support Bezier Curve with degree > 25. This should not be a problem in practice.
|[[Draft_Workbench|Draft]]
{{clear}}
|IconL=Draft_CubicBezCurve.svg
<languages/>
|IconR=Draft_Point.svg
|IconC=Workbench_Draft.svg
}}

{{Draft Tools navi{{#translation:}}}}
{{Userdocnavi{{#translation:}}}}

Latest revision as of 04:56, 9 January 2024

Draft BezCurve

Menu location
Drafting → Bézier tools → Bézier curve
Workbenches
Draft, Arch
Default shortcut
B Z
Introduced in version
0.14
See also
Draft CubicBezCurve, Draft BSpline

Description

The Draft BezCurve command creates a Bézier curve from several points.

The command creates a single Bézier curve with a DataDegree that is number_of_points - 1. It can be transformed into a piecewise Bézier curve by reducing this property.

The Draft BezCurve and the Draft CubicBezCurve commands use control points to define the position and curvature of the spline. The Draft BSpline command, on the other hand, specifies the exact points through which the curve will pass.

Bézier curve defined by multiple points

Usage

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

  1. There are several ways to invoke the command:
  2. The Bézier curve task panel opens. See Options for more information.
  3. Pick the first point in the 3D view, or type coordinates and press the Enter point button.
  4. Pick additional points in the 3D view, or type coordinates and press the Enter point button.
  5. Press Esc or the Close button to finish the command.

Options

The single character keyboard shortcuts available in the task panel can be changed. See Draft Preferences. The shortcuts mentioned here are the default shortcuts (for version 0.22).

  • 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 F or click the Filled checkbox to toggle filled mode. If filled mode is on, the created curve will have DataMake Face set to true and will have a filled face, provided it is closed and does not self-intersect. Note that a self-intersecting curve with a face will not display properly, for such a curve DataMake Face must be set to false.
  • Press N or click the Continue checkbox to toggle continue mode. If continue mode is on, the command will restart after using Finish or Close, or after creating a closed curve by snapping to the first point of the curve, allowing you to continue creating curves.
  • Press / or the Undo button to undo the last point.
  • Press A or the Finish button to finish the command and leave the curve open.
  • Press O or the Close button to finish the command and close the curve. A closed curve can also be created by snapping to the first point of the curve.
  • Press W or the Wipe button to delete the segments already placed, but keep working from the last point.
  • Press U or the Set WP button to adjust the current working plane in the orientation defined by the last and the previous point.
  • Press S to switch Draft snapping on or off.
  • Press Esc or the Close button to finish the command.

Notes

  • A Draft BezCurve can be edited with the Draft Edit command.
  • OpenCascade, and therefore FreeCAD, does not support Bézier curves of degrees larger than 25. This should not be a problem in practice, as most users typically use Bézier curves of degrees 3 to 5.

Properties

See also: Property editor.

A Draft BezCurve object is derived from a Part Part2DObject and inherits all its properties. It also has the following additional properties:

Data

Draft

  • DataArea (Area): (read-only) specifies the area of the face of the curve. The value will be 0.0 if DataMake Face if false or the face cannot be created.
  • DataClosed (Bool): specifies if the curve is closed or not. If the curve is initially open this value is false, setting it to true will draw a segment to close the curve. If the curve is initially closed this value is true, setting it to false will remove the last segment and make the curve open.
  • DataContinuity (IntegerList): (read-only) specifies the continuity of the curve.
  • DataDegree (Integer): specifies the degree of the curve.
  • DataLength (Length): (read-only) specifies the total length of the curve.
  • DataMake Face (Bool): specifies if the curve makes a face or not. If it is true a face is created, otherwise only the perimeter is considered part of the object. This property only works if DataClosed is true and if the curve does not self-intersect.
  • DataPoints (VectorList): specifies the control points of the curve in its local coordinate system.

View

Draft

  • ViewArrow Size (Length): specifies the size of the symbol displayed at the end of the curve.
  • ViewArrow Type (Enumeration): specifies the type of symbol displayed at the end of the curve, which can be Dot, Circle, Arrow, Tick or Tick-2.
  • ViewEnd Arrow (Bool): specifies whether to show a symbol at the end of the curve, so it can be used as an annotation line.
  • ViewPattern (Enumeration): specifies the Draft Pattern with which to fill the face of the closed curve. This property only works if DataMake Face is true and if ViewDisplay Mode is Flat Lines.
  • ViewPattern Size (Float): specifies the size of the Draft Pattern.

Scripting

See also: Autogenerated API documentation and FreeCAD Scripting Basics.

To create a Draft Line use the make_bezcurve method (introduced in version 0.19) of the Draft module. This method replaces the deprecated makeBezCurve method.

bezcurve = make_bezcurve(pointslist, closed=False, placement=None, face=None, support=None, degree=None)
bezcurve = make_bezcurve(Part.Wire, closed=False, placement=None, face=None, support=None, degree=None)
  • Creates a bezcurve object with the given list of points, pointslist.
    • Each point in the list is defined by its FreeCAD.Vector, with units in millimeters.
    • Alternatively, the input can be a Part.Wire, from which points are extracted.
  • If closed is True, or if the first and last points are identical, the curve is closed.
  • If placement is None the curve is created at the origin.
  • If face is True, and the curve is closed, the curve will make a face, that is, it will appear filled.

Example:

import FreeCAD as App
import Draft

doc = App.newDocument()

p1 = App.Vector(0, 0, 0)
p2 = App.Vector(1000, 1000, 0)
p3 = App.Vector(2000, 0, 0)
p4 = App.Vector(1500, -2000, 0)

bezcurve1 = Draft.make_bezcurve([p1, p2, p3, p4], closed=True)
bezcurve2 = Draft.make_bezcurve([p4, 1.3*p2, p1, 4.1*p3], closed=True)
bezcurve3 = Draft.make_bezcurve([1.7*p3, 1.5*p4, 2.1*p2, p1], closed=True)

doc.recompute()