Sketcher ConstrainAngle: Difference between revisions

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|Workbenches=[[Sketcher_Workbench|Sketcher]]
|Workbenches=[[Sketcher_Workbench|Sketcher]]
|Shortcut={{KEY|K}} {{KEY|A}}
|Shortcut={{KEY|K}} {{KEY|A}}
|SeeAlso=[[Sketcher_ConstrainDistance|Sketcher Constrain distance]], [[Sketcher_ConstrainPerpendicular|Sketcher Constraint Perpendicular]]
|SeeAlso=[[Sketcher_ConstrainPerpendicular|Sketcher ConstrainPerpendicular]]
}}
}}


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<!--T:4-->
<!--T:4-->
The [[Image:Sketcher_ConstrainAngle.svg|24px]] [[Sketcher_ConstrainAngle|Sketcher ConstrainAngle]] tool is a [[Sketcher_Workbench#Sketcher_constraints|datum constraint]] intended to fix angles in a sketch. It is capable of setting slopes of individual lines, angles between lines, angles of intersections of curves, and angle spans of circular arcs. Lines are treated as infinite, and arcs are treated as full circles/ellipses.
The [[Image:Sketcher_ConstrainAngle.svg|24px]] [[Sketcher_ConstrainAngle|Sketcher ConstrainAngle]] tool fixes the angle between two edges (lines are then treated as infinite, and open curves are virtually extended as well), the angle of a line with the X axis, or the aperture angle of a circular arc.


==Usage== <!--T:5-->
==Usage== <!--T:5-->
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#* {{Version|0.22}}: Right-click in the [[3D_view|3D view]] and select the {{MenuCommand|Dimension → [[Image:Sketcher_ConstrainAngle.svg|16px]] Constrain angle}} option from the context menu.
#* {{Version|0.22}}: Right-click in the [[3D_view|3D view]] and select the {{MenuCommand|Dimension → [[Image:Sketcher_ConstrainAngle.svg|16px]] Constrain angle}} option from the context menu.
#* Use the keyboard shortcut: {{KEY|K}} then {{KEY|A}}.
#* Use the keyboard shortcut: {{KEY|K}} then {{KEY|A}}.
# The cursor changes to a white cross with the tool icon.
# The cursor changes to a cross with the tool icon.
# Do one of the following:
# Do one of the following:
#* Select two lines.
#* Select two lines.
#* Select a point and two edges (in that order).
#* Select a point and two edges (in that order).
#* Select an edge, a point and an edge (idem).
#* Select an edge, a point and an edge (idem).
# If a [[Sketcher_ToggleDrivingConstraint|driving constraint]] is created, and the {{MenuCommand|Ask for value after creating a dimensional constraint}} [[Sketcher_Preferences#Display|preference]] is selected (default):
# If a [[Sketcher_ToggleDrivingConstraint|driving dimensional constraint]] is created, depending on the [[Sketcher_Preferences#Display|preferences]], a dialog opens to [[Sketcher_Workbench#Edit_constraints|edit its value]]. A negative value will reverse the angle direction.
# An Angle constraint is added. If a point and two edges have been selected, up to two [[Sketcher_ConstrainPointOnObject|Point to object constraints]] can also be added. See [[#Between_two_edges_at_point|Examples]].
## A dialog opens to edit the constraint value.
## Press the {{Button|OK}} button to confirm.
# A constraint is added.
# Optionally keep creating constraints.
# Optionally keep creating constraints.
# To finish, right-click or press {{KEY|Esc}}, or start another geometry or constraint creation tool.
# To finish, right-click or press {{KEY|Esc}}, or start another geometry or constraint creation tool.


===Once-only mode===
===Run-once mode===


# Do one of the following:
# Do one of the following:
#* Select a single line.
#* Select a single line.
#* Select a single arc.
#* Select a single circular arc.
#* Select two lines.
#* Select two lines.
#* Select a point and two edges (in any order).
#* Select a point and two edges (in any order).
# Invoke the tool as explained above.
# Invoke the tool as explained above.
# Edit and/or confirm the constraint value as explained above.
# Optionally [[Sketcher_Workbench#Edit_constraints|edit the constraint value]].
# An Angle constraint is added. If a point and two edges have been selected, up to two [[Sketcher_ConstrainPointOnObject|Point on object constraints]] can also be added. See [[#Between_two_edges_at_point|Examples]].
# A constraint is added.


==Examples==
==Examples==


===Line slope angle=== <!--T:31-->
===Single line=== <!--T:31-->


</translate>
<!--T:32-->
[[Image:Sketcher_ConsraintAngle_mode1.png|400px]]
'''Accepted selection:''' line
<translate>

<!--T:9-->
[[Image:Sketcher ConsraintAngle mode1.png|600px]]


<!--T:10-->
<!--T:10-->
The constraint sets the polar angle of line's direction. It is the angle between the line and X axis of the sketch.
The angle of the line with the positive X axis of the sketch is fixed.


===Span of a circular arc=== <!--T:33-->
===Single circular arc=== <!--T:33-->


</translate>
<!--T:11-->
[[Image:Sketcher_ConsraintAngle_mode2.png|400px]]
'''Accepted selection:''' arc of circle
<translate>

<!--T:12-->
[[Image:Sketcher ConsraintAngle mode2.png|600px]]


<!--T:13-->
<!--T:13-->
The aperture angle of the arc is fixed.
In this mode, the constraint fixes angular span of a circular arc.


===Between lines=== <!--T:34-->
===Between two lines=== <!--T:34-->


</translate>
<!--T:14-->
[[Image:Sketcher_ConsraintAngle_mode3.png|400px]]
'''Accepted selection:''' line + line
<translate>

<!--T:15-->
[[Image:Sketcher ConsraintAngle mode3.png|600px]]


<!--T:16-->
<!--T:16-->
In this mode, the constraint sets the angle between two lines. It is not required that the lines intersect.
The angle between the two lines is fixed. It is not required that the lines intersect.

===Between curves at intersection (angle-via-point)=== <!--T:35-->

<!--T:17-->
'''Accepted selection:''' any line/curve + any line/curve + any point


<!--T:18-->
===Between two edges at point=== <!--T:35-->
[[Image:Sketcher ConsraintAngle mode4.png|600px]]


</translate>
<!--T:19-->
[[Image:Sketcher_ConsraintAngle_mode4.png|400px]]
In this mode, angle between two curves is constrained at the point of their intersection. The intersection point can be on curves' extensions. The point should be specified explicitly, since curves typically intersect in more than one point.
<translate>


The angle between the two edges at a given point is fixed. The point can be any point, e.g. the center of a circle, the endpoint of an edge, or the origin, it can belong to either or both edges, and it can also be a [[Sketcher_CreatePoint|Point object]]. If required [[Sketcher_ConstrainPointOnObject|Point on object constraint(s)]] are added to ensure the point lies on both (extended) edges. These additional constraints are called [[Sketcher_helper_constraint|helper constraints]].
<!--T:20-->
For the constraint to work correctly, the point must be on both curves. So, as the constraint is invoked, the point will be automatically constrained onto both curves ([[Sketcher_helper_constraint|helper constraints]] will be added, if necessary), and the angle between curves will be constrained at the point. These [[Sketcher_helper_constraint|helper constraints]] are plain regular constraints. They can be added manually, or deleted. There are no helper constraints on the example picture above, because the point selected is already the intersection of curves.


==Scripting== <!--T:21-->
==Scripting== <!--T:21-->

Revision as of 08:11, 19 April 2024

This documentation is a work in progress. Please don't mark it as translatable since it will change in the next hours and days.

Sketcher ConstrainAngle

Menu location
Sketch → Sketcher constraints → Constrain angle
Workbenches
Sketcher
Default shortcut
K A
Introduced in version
-
See also
Sketcher ConstrainPerpendicular

Description

The Sketcher ConstrainAngle tool fixes the angle between two edges (lines are then treated as infinite, and open curves are virtually extended as well), the angle of a line with the X axis, or the aperture angle of a circular arc.

Usage

See also: Drawing aids.

Continue mode

  1. Make sure there is no selection.
  2. There are several ways to invoke the tool:
    • introduced in version 0.22: If the Dimensioning constraints preference is set to Single tool (default): press the down arrow to the right of the button and select the Constrain angle option from the dropdown.
    • If this preference has a different value (and in version 0.21 and below): press the Constrain angle button.
    • Select the Sketch → Sketcher constraints → Constrain angle option from the menu.
    • introduced in version 0.22: Right-click in the 3D view and select the Dimension → Constrain angle option from the context menu.
    • Use the keyboard shortcut: K then A.
  3. The cursor changes to a cross with the tool icon.
  4. Do one of the following:
    • Select two lines.
    • Select a point and two edges (in that order).
    • Select an edge, a point and an edge (idem).
  5. If a driving dimensional constraint is created, depending on the preferences, a dialog opens to edit its value. A negative value will reverse the angle direction.
  6. An Angle constraint is added. If a point and two edges have been selected, up to two Point to object constraints can also be added. See Examples.
  7. Optionally keep creating constraints.
  8. To finish, right-click or press Esc, or start another geometry or constraint creation tool.

Run-once mode

  1. Do one of the following:
    • Select a single line.
    • Select a single circular arc.
    • Select two lines.
    • Select a point and two edges (in any order).
  2. Invoke the tool as explained above.
  3. Optionally edit the constraint value.
  4. An Angle constraint is added. If a point and two edges have been selected, up to two Point on object constraints can also be added. See Examples.

Examples

Single line

The angle of the line with the positive X axis of the sketch is fixed.

Single circular arc

The aperture angle of the arc is fixed.

Between two lines

The angle between the two lines is fixed. It is not required that the lines intersect.

Between two edges at point

The angle between the two edges at a given point is fixed. The point can be any point, e.g. the center of a circle, the endpoint of an edge, or the origin, it can belong to either or both edges, and it can also be a Point object. If required Point on object constraint(s) are added to ensure the point lies on both (extended) edges. These additional constraints are called helper constraints.

Scripting

Angle Constraint can be created from macros and from the Python console by using the following:

# line slope angle
Sketch.addConstraint(Sketcher.Constraint('Angle',iline,angle))

# angular span of arc
Sketch.addConstraint(Sketcher.Constraint('Angle',iarc,angle))

# angle between lines
Sketch.addConstraint(Sketcher.Constraint('Angle',iline1,pointpos1,iline2,pointpos2,angle))

# angle-via-point (no helper constraints are added automatically when from python)
Sketch.addConstraint(Sketcher.Constraint('AngleViaPoint',icurve1,icurve2,geoidpoint,pointpos,angle))

where:

  • Sketch is a sketch object
  • iline, iline1, iline2 are integers specifying the lines by their ordinal numbers in Sketch.
  • pointpos1, pointpos2 should be 1 for start point and 2 for end point. The choice of endpoints allows to set internal angle (or external), and it affects how the constraint is drawn on the screen.
  • geoidpoint and pointpos in AngleViaPoint are the indexes specifying the point of intersection.
  • angle is the angle value in radians. The angle is counted between tangent vectors in counterclockwise direction. Tangent vectors are pointing from start to end for the lines (or vice versa if ending point is supplied in angle between lines mode), and along counterclockwise direction for circles, arcs and ellipses. Quantity is also accepted as an angle (e.g. App.Units.Quantity('45 deg'))

The Sketcher scripting page explains the values which can be used for iline, iline1, iline2, pointpos1, pointpos2, geoidpoint and pointpos and contains further examples on how to create constraints from Python scripts.