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<languages/>

{{Docnav/ru
|[[Sketcher_ToggleConstruction/ru|Переключить построительную геометрию]]
|[[Sketcher_ConstrainPointOnObject/ru|Зафиксировать точку на объекте]]
|[[Sketcher_Workbench/ru|Верстак "Sketcher"]]
|IconL=Sketcher_ToggleConstruction.svg
|IconR=Constraint_PointOnObject.svg
|IconC=Workbench_Sketcher.svg
}}

{{GuiCommand/ru
{{GuiCommand/ru
|Name/ru=Ограничение коинциндентности
|Name=Constraint PointOnPoint
|Name=Sketcher_ConstrainCoincident
|Name/ru=Constraint PointOnPoint
|Workbenches=[[Sketcher Workbench/ru|Sketcher]], [[PartDesign Workbench/ru|PartDesign]]
|MenuLocation=Sketch → Ограничения эскиза → Ограничение коинциндентности
|MenuLocation=Sketch → Ограничения эскиза → Ограничение коинциндентности
|Workbenches=[[Sketcher_Workbench/ru|Sketcher]]
|SeeAlso=[[Constraint Lock/ru|Constraint Lock]], [[Constraint PointOnObject/ru|Constraint Point onto Object]]}}
|Shortcut={{KEY|C}}
|SeeAlso=[[Sketcher_ConstrainLock/ru|Ограничение положения]], [[Sketcher_ConstrainPointOnObject/ru|Зафиксировать точку на объекте]]
}}

==Описание==

Create a coincident constraint on the selected item


"Create a coincident constraint on the selected item"
====Description====
This constraint tool takes two points as its argument and serves to make the two points ''coincident''. (Meaning to make them as-one-point).
This constraint tool takes two points as its argument and serves to make the two points ''coincident''. (Meaning to make them as-one-point).

In practical terms this constraint tool is useful when there is a break in a profile for example - where two lines end near each other and need to be joined - a coincident constraint on their end-points will close the gap.
In practical terms this constraint tool is useful when there is a break in a profile for example - where two lines end near each other and need to be joined - a coincident constraint on their end-points will close the gap.


==Применение==
====Usage====

As stated above, this tool takes two arguments - both are points.
As stated above, this tool takes two arguments - both are points.
#Firstly it is necessary to highlight two distinct points. (Note this will not work if, for example, you attempt to select the start and end point of the same line).
# First, it is necessary to highlight two distinct points. ({{Emphasis|Note:}} this will not work if, for example, you attempt to select the start and end point of the same straight line; selecting the start and end points of an arc will produce a closed circle or ellipse but will constrain the location of the seam to be on that point).
#Highlighting of a drawing item is achieved by moving the mouse over the item and clicking the left-mouse-button.
# Highlighting of a drawing item is achieved by moving the mouse over the item and clicking the left-mouse-button.
# It is also possible to highlight all items inside a rectangle by clicking and dragging. When dragging from left to right (with any vertical motion), only the shapes which are entirely contained within the rectangle will be highlighted; in the other direction all shapes which intersect with the selection rectangle will be highlighted. This can be used to select only the vertices without selecting the edges, by dragging a small recangle around some vertices from left to right, as long as there are no edges which are fully contained within the rectangle.
#A highlighted item will change colour to green.
# A highlighted item will change its color to green. (This color can be customized in {{MenuCommand|Editing → Preference → Display → Colors → Selection}})
#Subsequent items can be highlighted by repeating the above procedure(s) NOTE: There is no-need to hold-down any special key like Ctrl to achieve multiple item selection in a drawing.
# Subsequent items can be highlighted by repeating the above procedure(s). {{Emphasis|Note:}} it's unnecessary to hold-down any special key like {{KEY|Ctrl}} to achieve multiple item selection in a drawing.
#Once you have two points highlighted, left-clicking on the 'PointOnPoint' constraint will cause the two points to become ''coincident'' and be replaced by a single point.
# Once you have two points highlighted, you can invoke the command using several methods:
NOTE: In order to make two points coincident, FreeCAD must necessarily move one, or both, of the original points.
#* Pressing on the {{Button|[[File:Sketcher_ConstrainCoincident.svg|16px]] [[Sketcher_ConstrainCoincident|Coinstrain coincident]]}} constraint button in the toolbar.
#* Using the {{KEY|C}} keyboard shortcut.
#* Using the {{MenuCommand|Sketch → Sketcher constraints → Constrain coincident}} entry in the top menu.
{{Emphasis|Result:}} the command will cause the two points to become ''coincident'' and be replaced by a single point.


{{Emphasis|Note:}} In order to make two points coincident, FreeCAD must out of necessity move one (or both) of the original points.

== Alternatives to Coincident constraint ==

The two constrained items of a [[Sketcher_ConstrainCoincident|Coincident]] constraint must be start point or end point vertices, or center points of arcs, circles or ellipses. Some combinations which are not possible with a coincident constraint can be emulated using other constraints:
* The [[File:Sketcher_ConstrainSymmetric.svg|24px]] [[Sketcher_ConstrainSymmetric|Symmetric]] constraint can be used to place a start point, end point or center point on the midpoint of a straight line.
* A midpoint-to-midpoint placement of two straight lines can be achieved by creating a new [[File:Sketcher_CreatePoint.svg|24px]] [[Sketcher_CreatePoint|Point]] and using two [[File:Sketcher_ConstrainSymmetric.svg|24px]] [[Sketcher_ConstrainSymmetric|Symmetric]] constraints so that it lies on the midpoint of both lines.
* A vertex can be constrained to lie along an edge using a [[File:Sketcher_ConstrainPointOnObject.svg|24px]][[Sketcher_ConstrainPointOnObject|PointOnObject]] constraint. Note that with this constraint, the point can lie anywhere on the full extension of a segment or curve (i.e. also before the start point or beyond the end point).
* A collinear placement of two straight lines can be obtained by applying a [[File:Sketcher_ConstrainTangent.svg|24px]] [[Sketcher_ConstrainTangent|Tangent]] constraint to them, or by combining a [[File:Sketcher_ConstrainPointOnObject.svg|24px]] [[Sketcher_ConstrainPointOnObject|PointOnObject]] constraint and a [[File:Sketcher_ConstrainParallel.svg|24px]] [[Sketcher_ConstrainParallel|Parallel]] constraint.
* Two edges can be made identical by using two [[File:Sketcher_ConstrainCoincident.svg|24px]] [[Sketcher_ConstrainCoincident|Coincident]] constraints, one for each pair of extremities.
* Two circles can be made identical by using a [[File:Sketcher_ConstrainCoincident.svg|24px]] [[Sketcher_ConstrainCoincident|Coincident]] constraint to merge the centers, and applying an [[File:Sketcher_ConstrainEqual.svg|24px]] [[Sketcher_ConstrainEqual|Equal]] constraint to their edges. For arcs, this will ensure both arcs are part of the same circle, while allowing them to have different start and end points.

==Программирование==

The constraint can be created from [[Macros|macros]] and from the [[Python|Python]] console by using the following command:

{{Code|code=Sketch.addConstraint(Sketcher.Constraint('Coincident',LineFixed,PointOfLineFixed,LineMoving,PointOfLineMoving)) }}

where :
* {{incode|Sketch}} is a sketch object
* {{incode|LineFixed}} is the number of the line, that will not move by applying the constraint
* {{incode|PointOfLineFixed}} indicates which vertex of {{incode|LineFixed}} has to fulfill the constraint
* {{incode|LineMoving}} is the number of the line, that will move by applying the constraint
* {{incode|PointOfLineMoving}} indicates which vertex of {{incode|LineMoving}} has to fulfill the constraint

As the names {{incode|LineFixed}} and {{incode|LineMoving}} indicate, if both constrained vertices are free to move in any direction, the first one (first to be selected in the Gui) will remain fixed and the other one will move. In the presence of existing constraints, however, both edges may move.

The [[Sketcher_scripting|Sketcher scripting]] page explains the values which can be used for {{incode|LineFixed}}, {{incode|PointOfLineFixed}}, {{incode|LineMoving}} and {{incode|PointOfLineMoving}}, and contains further examples on how to create constraints from Python scripts.


{{Docnav/ru
|[[Sketcher_ToggleConstruction/ru|Переключить построительную геометрию]]
|[[Sketcher_ConstrainPointOnObject/ru|Зафиксировать точку на объекте]]
|[[Sketcher_Workbench/ru|Верстак "Sketcher"]]
|IconL=Sketcher_ToggleConstruction.svg
|IconR=Constraint_PointOnObject.svg
|IconC=Workbench_Sketcher.svg
}}

{{Sketcher Tools navi{{#translation:}}}}
{{Userdocnavi{{#translation:}}}}
{{clear}}
{{clear}}
<languages/>

Revision as of 18:29, 13 September 2021

Ограничение коинциндентности

Системное название
Sketcher_ConstrainCoincident
Расположение в меню
Sketch → Ограничения эскиза → Ограничение коинциндентности
Верстаки
Sketcher
Быстрые клавиши
C
Представлено в версии
-
См. также
Ограничение положения, Зафиксировать точку на объекте

Описание

Create a coincident constraint on the selected item

This constraint tool takes two points as its argument and serves to make the two points coincident. (Meaning to make them as-one-point).

In practical terms this constraint tool is useful when there is a break in a profile for example - where two lines end near each other and need to be joined - a coincident constraint on their end-points will close the gap.

Применение

As stated above, this tool takes two arguments - both are points.

  1. First, it is necessary to highlight two distinct points. (Note: this will not work if, for example, you attempt to select the start and end point of the same straight line; selecting the start and end points of an arc will produce a closed circle or ellipse but will constrain the location of the seam to be on that point).
  2. Highlighting of a drawing item is achieved by moving the mouse over the item and clicking the left-mouse-button.
  3. It is also possible to highlight all items inside a rectangle by clicking and dragging. When dragging from left to right (with any vertical motion), only the shapes which are entirely contained within the rectangle will be highlighted; in the other direction all shapes which intersect with the selection rectangle will be highlighted. This can be used to select only the vertices without selecting the edges, by dragging a small recangle around some vertices from left to right, as long as there are no edges which are fully contained within the rectangle.
  4. A highlighted item will change its color to green. (This color can be customized in Editing → Preference → Display → Colors → Selection)
  5. Subsequent items can be highlighted by repeating the above procedure(s). Note: it's unnecessary to hold-down any special key like Ctrl to achieve multiple item selection in a drawing.
  6. Once you have two points highlighted, you can invoke the command using several methods:
    • Pressing on the Coinstrain coincident constraint button in the toolbar.
    • Using the C keyboard shortcut.
    • Using the Sketch → Sketcher constraints → Constrain coincident entry in the top menu.

Result: the command will cause the two points to become coincident and be replaced by a single point.

Note: In order to make two points coincident, FreeCAD must out of necessity move one (or both) of the original points.

Alternatives to Coincident constraint

The two constrained items of a Coincident constraint must be start point or end point vertices, or center points of arcs, circles or ellipses. Some combinations which are not possible with a coincident constraint can be emulated using other constraints:

  • The Symmetric constraint can be used to place a start point, end point or center point on the midpoint of a straight line.
  • A midpoint-to-midpoint placement of two straight lines can be achieved by creating a new Point and using two Symmetric constraints so that it lies on the midpoint of both lines.
  • A vertex can be constrained to lie along an edge using a PointOnObject constraint. Note that with this constraint, the point can lie anywhere on the full extension of a segment or curve (i.e. also before the start point or beyond the end point).
  • A collinear placement of two straight lines can be obtained by applying a Tangent constraint to them, or by combining a PointOnObject constraint and a Parallel constraint.
  • Two edges can be made identical by using two Coincident constraints, one for each pair of extremities.
  • Two circles can be made identical by using a Coincident constraint to merge the centers, and applying an Equal constraint to their edges. For arcs, this will ensure both arcs are part of the same circle, while allowing them to have different start and end points.

Программирование

The constraint can be created from macros and from the Python console by using the following command:

Sketch.addConstraint(Sketcher.Constraint('Coincident',LineFixed,PointOfLineFixed,LineMoving,PointOfLineMoving))

where :

  • Sketch is a sketch object
  • LineFixed is the number of the line, that will not move by applying the constraint
  • PointOfLineFixed indicates which vertex of LineFixed has to fulfill the constraint
  • LineMoving is the number of the line, that will move by applying the constraint
  • PointOfLineMoving indicates which vertex of LineMoving has to fulfill the constraint

As the names LineFixed and LineMoving indicate, if both constrained vertices are free to move in any direction, the first one (first to be selected in the Gui) will remain fixed and the other one will move. In the presence of existing constraints, however, both edges may move.

The Sketcher scripting page explains the values which can be used for LineFixed, PointOfLineFixed, LineMoving and PointOfLineMoving, and contains further examples on how to create constraints from Python scripts.