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==Description==
==Description==
Angle constraint a [[Sketcher Datum Constraint|datum constraint]] intended to fix angles in sketch. It is capable of setting slopes of individual lines, angles between lines, angles of intersections of curves, and angle spans of circular arcs.
Perpendicular Constraint makes two lines to be perpendicular to each other, or two curves to be perpendicular at their intersection. Lines are treated infinite, and arcs are treated as full circles/ellipses. The constraint is also capable of connecting two curves, forcing them perpendicular at the joint, similarly to [[Constraint Tangent|Tangent Constraint]].


==How to use==
==How to use==
There are four different ways the constraint can be applied:
There are four different ways the constraint can be applied:
# to a single line
# between two curves (available not for all curves)
# between two endpoints of a curve
# between two lines
# to an intersection of two curves
# between a curve and an endpoint of another curve
# to arcs of circles
# between two curves at user-defined point


To apply perpendicular constraint, one should the follow the steps:
To apply perpendicular constraint, one should the follow the steps:
* Select two or three entities in the sketch.
* Select one, two or three entities in the sketch.
* Invoke the constraint by clicking its icon on the toolbar, or selecting the menu item, or using keyboard shortcut.
* Invoke the constraint by clicking its icon on the toolbar, or selecting the menu item, or using keyboard shortcut. A datum edit dialog box pops up.
* Modify the angle if necessary. Click OK.


===To a single line===
===Between two curves (direct perpendicularity)===
[[Image:Sketcher ConsraintPerpendicular mode1.png|600px]]
[[Image:Sketcher ConsraintAngle mode1.png|600px]]


Two curves will be made perpendicular at point of their intersection (either real, or of curves' extensions), and the point of intersection will be implicit. This mode is applied if two curves were selected.
The constraint sets the polar angle of line's direction. It is the angle between the line and X axis of the sketch. This mode is applied if one line was selected.


'''Accepted selection:'''
'''Accepted selection:'''
* line + line, circle, arc
* line
* circle, arc + circle, arc
If direct perpendicularity between selected curves is not supported (e.g. between a line and an ellipse), a helper point will be added to sketch automatically, and perpendicular-via-point will be applied.


===Between two lines===
Unlike for tangency, it is perfectly fine to reconstruct the point of perpendicularity by creating a point and constraining it to lie on both curves (thus constraining the point to the intersection).
[[Image:Sketcher ConsraintAngle mode2.png|600px]]


In this mode, the constraint sets the angle between two lines. It is not required that the lines intersect. This mode is applied when two lines were selected.
===Between two endpoints (point-to-point perpendicularity)===
[[Image:Sketcher ConsraintPerpendicular mode2.png|600px]]

In this mode, the endpoints are made coincident, and the joint is made to be right angle. This mode is applied when two endpoints of two curves were selected.


'''Accepted selection:'''
'''Accepted selection:'''
* line + line
* endpoint of line/arc/arc-of-ellipse + endpoint of line/arc/arc-of-ellipse (i.e., two endpoints of any two curves)


===Between curve and endpoint (point-to-curve perpendicularity)===
===Between two curves at intersection (angle-via-point) (v0.15)===
[[Image:Sketcher ConsraintPerpendicular mode3.png|600px]]
[[Image:Sketcher ConsraintAngle mode3.png|600px]]


In this mode, an endpoint of one curve is constrained to lie on the other curve, and the curves are forced perpendicular at the point. This mode is applied when a curve and an endpoint of another curve were selected.
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. This mode is applied when two curves and a point were selected.


'''Accepted selection:'''
'''Accepted selection:'''
* line, circle, arc, ellipse, arc-of-ellipse + endpoint of line/arc/arc-of-ellipse (i.e., any curve + endpoint of any curve)
* any line/curve + any line/curve + any point


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.


===Between two curves at point (perpendicular-via-point) (v0.15)===
===To an arc of circle (v0.15)===
[[Image:Sketcher ConsraintPerpendicular mode4.png|600px]]
[[Image:Sketcher ConsraintAngle mode4.png|600px]]


In this mode, two curves are made perpendicular, and the point of perpendicularity is tracked. This mode is applied when two curves and a point were selected.
In this mode, the constraint fixes angular span of a circular arc. This mode is applied when a circular arc was selected.


'''Accepted selection:'''
'''Accepted selection:'''
* arc of circle
* any line/curve + any line/curve + any point
"Any point" can be a lone point, or a point of something, e.g. a center of a circle, an endpoint of an arc, or the origin.

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 curves will be forced perpendicular at the point. These [[Sketcher helper constraint|helper constraints]] are plain regular constraints. They can be added manually, or deleted.

Compared to direct perpendicular, this constraint is slower, because there are mode degrees of freedom involved, but it supports ellipses.

The placement of the point before the constraint is applied is a hint for the solver for where the perpendicularity should be.


==Scripting==
==Scripting==


Perpendicular Constraint can be created from [[macros]] and from the python console by using the following:
Angle Constraint can be created from [[macros]] and from the python console by using the following:
</translate>
</translate>
{{Code|code=
{{Code|code=

Revision as of 22:07, 17 January 2015

Constraint InternalAngle

Menu location
Sketch → Sketcher constraints → Constrain angle
Workbenches
Sketcher, PartDesign
Default shortcut
A
Introduced in version
-
See also
Constraint Length, Constraint Perpendicular

Description

Angle constraint a datum constraint intended to fix angles in sketch. It is capable of setting slopes of individual lines, angles between lines, angles of intersections of curves, and angle spans of circular arcs.

How to use

There are four different ways the constraint can be applied:

  1. to a single line
  2. between two lines
  3. to an intersection of two curves
  4. to arcs of circles

To apply perpendicular constraint, one should the follow the steps:

  • Select one, two or three entities in the sketch.
  • Invoke the constraint by clicking its icon on the toolbar, or selecting the menu item, or using keyboard shortcut. A datum edit dialog box pops up.
  • Modify the angle if necessary. Click OK.

To a single line

The constraint sets the polar angle of line's direction. It is the angle between the line and X axis of the sketch. This mode is applied if one line was selected.

Accepted selection:

  • line

Between two lines

In this mode, the constraint sets the angle between two lines. It is not required that the lines intersect. This mode is applied when two lines were selected.

Accepted selection:

  • line + line

Between two curves at intersection (angle-via-point) (v0.15)

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. This mode is applied when two curves and a point were selected.

Accepted selection:

  • any line/curve + any line/curve + any point

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 (helper constraints will be added, if necessary), and the angle between curves will be constrained at the point. These helper constraints are plain regular constraints. They can be added manually, or deleted.

To an arc of circle (v0.15)

In this mode, the constraint fixes angular span of a circular arc. This mode is applied when a circular arc was selected.

Accepted selection:

  • arc of circle

Scripting

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

# direct perpendicularity
Sketch.addConstraint(Sketcher.Constraint('Perpendicular',icurve1,icurve2))

# point-to-point perpendicularity
Sketch.addConstraint(Sketcher.Constraint('Perpendicular',icurve1,pointpos1,icurve2,pointpos2))

# point-to-curve perpendicularity
Sketch.addConstraint(Sketcher.Constraint('Perpendicular',icurve1,pointpos1,icurve2))

# perpendicular-via-point (plain constraint, helpers are not added automatically)
Sketch.addConstraint(Sketcher.Constraint('PerpendicularViaPoint',icurve1,icurve2,geoidpoint,pointpos))

where:

  • Sketch is a sketch object
  • icurve1, icurve2 are two integers identifying the curves to be made perpendicular. The integers are indexes in the sketch (the value, returned by Sketch.addGeometry).
  • pointpos1, pointpos2 should be 1 for start point and 2 for end point.
  • geoidpoint and pointpos in PerpendicularViaPoint are the indexes specifying the point of perpendicularity.