Vazba souměrnosti
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| Umístění Menu |
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| Sketch → Sketcher constraints → Constrain symmetrical |
| Pracovní stoly |
| Náčrt, Návrh dílu |
| Výchozí zástupce |
| Nikdo |
| Představen ve verzi |
| - |
| Viz také |
| Vazba rovnoběžnosti |
Contents |
Description
Popis
Vazba souměrnosti zajistí, že dva vybrané body jsou souměrné podle zadané přímky, např. oba vybrané body budou ležet na kolmici k přímce procházející oběma body a budou stejně vzdálené od přímky. Případně oba body mohou být souměrně uloženy ke třetímu bodu.
Postup
Vyberte v náčrtu dva body (vrcholy) a přímku. Vybrané body a přímka změní barvu na tmavězelenou.
Klikněte na ikonu Vazba souměrnosti 
v nástrojovém pruhu Náčrtu nebo vyberte položku Vazba souměrnosti ze submenu Vazba souměrnosti z menu Náčrtu (nebo Návrh dílu).
Tím aplikujete vazbu na vybrané položky.
Toto je geometrické vazba a nemá žádné parametry.
Select two points (vertexes) in the sketch and a line in the sketch. The selected points and the line will be dark green.
Click on 
Constrain symmetric or select the Constrain Symmetrical menu item from the Sketcher Constraints sub menu of the Sketcher (or Part Design) menu item.
This will apply the constraint to the selected items.
Note: Before Version 0.19 (see fix [1]), if you want to define a symmetry constraint with respect to a point, the order of the selection is important, depending on if you select the tool at the beginning or at the end.
- If you click the tool first: select the first point, then the symmetry reference point, and finally the second point.
- If you click the tool last: select the first point, then the second point, and finally the symmetry reference point.
See the tracker issue #4144, and forum thread.
Scripting
Two points and a symmetry line:
Sketch.addConstraint(Sketcher.Constraint('Symmetric', Line1, PointOfLine1, Line2, PointOfLine2, SymmetryLine))
Two points and a symmetry point:
Sketch.addConstraint(Sketcher.Constraint('Symmetric', Line1, PointOfLine1, Line2, PointOfLine2, LineS, PointOfLineS))
A line and a symmetry point (In the GUI one can select a line and a point, but it uses internally the same form as above, with the two extremities of the same line):
Sketch.addConstraint(Sketcher.Constraint('Symmetric', Line, 1, Line, 2, LineS, PointOfLineS))
The Sketcher scripting page explains the values which can be used for Line1, Line2, LineS, Line, PointOfLine1, PointOfLine2 and PointOfLineS, and contains further examples on how to create constraints from Python scripts.
- The tools: New sketch, Edit sketch, Leave sketch, View sketch, View section, Map sketch to face, Reorient sketch, Validate sketch, Merge sketches, Mirror sketch
- Sketcher geometries: Point, Line by 2 point, Create an arc, Arc, Arc by 3 Point, Create a circle, Circle, Circle by 3 Point, Create a conic, Ellipse by center, Ellipse by 3 points, Arc of ellipse, Arc of hyperbola, Arc of parabola, Create a B-spline, Create B-spline, Create periodic B-pline, Polyline (multiple-point line), Rectangle, Create regular polygon, Triangle, Square, Pentagon, Hexagon, Heptagon, Octagon, Create Regular Polygon, Slot, Fillet, Trimming, Extend, External Geometry, CarbonCopy, Construction Mode
- Sketcher constraints
- Geometric constraints Coincident, Point On Object, Vertical, Horizontal, Parallel, Perpendicular, Tangent, Equal Length, Symmetric, Constrain Block
- Dimensional constraints Lock, Horizontal Distance, Vertical Distance, Distance, Radius, Internal Angle, Snell's Law, Internal Alignment, Toggle reference/driving constraint,
- Sketcher tools Select solver DOFs, Close Shape, Connect Edges, Select Constraints, Select Origin, Select Vertical Axis, Select Horizontal Axis, Select Redundant Constraints, Select Conflicting Constraints, Select Elements Associated with constraints, Show/Hide internal geometry, Symmetry, Clone, Copy, Move, Rectangular Array, Delete All Geometry, Delete All Constraints
- Sketcher B-spline tools Show/Hide B-spline degree, Show/Hide B-spline control polygon, Show/Hide B-spline curvature comb, Show/Hide B-spline knot multiplicity, Convert Geometry to B-spline, Increase degree, Increase knot multiplicity, Decrease knot multiplicity
- Sketcher virtual space Switch Virtual Space
- Installation: Windows, Linux, Mac; Getting started
- Basics: About FreeCAD, Workbenches, Preferences, Document structure, Interface Customization, Properties, Mouse Model; Tutorials
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- Scripting: Introduction to Python, FreeCAD scripting tutorial, FreeCAD Scripting Basics, How to install macros, Gui Command, Units Modules: Builtin modules, Workbench creation, Installing more workbenches Meshes: Mesh Scripting, Mesh Module Parts: The Part Module, Topological data scripting, PythonOCC, Mesh to Part Coin scenegraph: The Coin/Inventor scenegraph, Pivy Qt interface: PySide, Using the FreeCAD GUI, Dialog creation Parametric objects: Scripted objects Other: Code snippets, Line drawing function, Embedding FreeCAD, FreeCAD vector math library, Power users hub, Python, Macros, FreeCAD Scripting Basics, Topological data scripting
