Sketcher SketchObject

Introduction

A Sketcher SketchObject, or formally a Sketcher::SketchObject, is the base element to create 2D objects with the Sketcher Workbench.

The Sketcher::SketchObject is derived from Part Part2DObject, which means it is a Part Feature object specialized for 2D geometry. Like Part2DObject, the SketchObject can be attached to planes and faces. In addition, the SketchObject can handle geometrical constraints of the lines and curves that are drawn within it.

Simplified diagram of the relationships between the core objects in FreeCAD. The Sketcher::SketchObject class is specialized for 2D shapes, and additionally it can handle geometrical constraints of its elements.

How to use

1. Switch to the Sketcher Workbench.
2. Press Sketcher NewSketch.
3. Select a Sketch orientation: XY-plane, XZ-plane, or YZ-plane. Optionally also choose Reverse direction, and give an Offset value.
4. Press OK.

Although the SketchObject can be used by itself to draw on a plane, it is most commonly used in conjunction with the PartDesign Workbench to create extruded solids.

1. Switch to the PartDesign Workbench.
2. Press PartDesign Body.
3. Press PartDesign NewSketch.
4. Select feature: XY_Plane (Base plane), XZ_Plane (Base plane), or YZ_Plane (Base plane).
5. Press OK.

Properties

See Property for all property types that scripted objects can have.

A Sketcher SketchObject (Sketcher::SketchObject class) is derived from a Part Part2DObject (Part::Part2DObject class), therefore it shares all the latter's properties.

In addition to the properties described in Part Part2DObject, the basic Sketcher SketchObject has the following properties in the property editor.

Data

Attachment

• DatenMap Mode: See Part Attachment for more information on all attachment mapping modes.

Sketch

• DatenConstraints: named constraints, if they exist; otherwise it is an empty list [].

View

Auto Constraints

• AnsichtAutoconstraints: if true it will try setting constraints when the geometry is drawn.

Visibility automation

• AnsichtEditing Workbench: normally SketcherWorkbench, it is the name of the workbench to activate when editing the sketch.
• AnsichtHide Dependent: if true all objects that depend on the sketch are hidden when opening the sketch.
• AnsichtRestore Camera: if true the camera position is saved before opening the sketch, and is restored after closing it.
• AnsichtShow Links: if true all objects used in links to external geometry are shown when opening the sketch.
• AnsichtShow Support: if true all objects this sketch is attached to are shown when opening the sketch.

Scripting

See also: FreeCAD Scripting Basics, and scripted objects.

See Part Feature for the general information on adding objects.

A Sketcher SketchObject is created with the addObject() method of the document.

import FreeCAD as App

doc = App.newDocument()
obj = App.ActiveDocument.addObject("Sketcher::SketchObject", "Sketch")
obj.Label = "Custom label"

Sketcher

• General: Create sketch, Edit sketch, Map sketch to face, Reorient sketch, Validate sketch, Merge sketches, Mirror sketch, Leave sketch, View sketch, View section, Toggle grid, Toggle snap, Configure rendering order, Stop operation

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• Sketcher geometries: Point, Line, Arc, Arc by 3 points, Circle, Circle by 3 points, Ellipse, Ellipse by 3 points, Arc of ellipse, Arc of hyperbola, Arc of parabola, B-spline by control points, Periodic B-spline by control points, B-spline by knots, Periodic B-spline by knots, Polyline, Rectangle, Centered rectangle, Rounded rectangle, Triangle, Square, Pentagon, Hexagon, Heptagon, Octagon, Regular polygon, Slot, Fillet, Corner-preserving fillet, Trim, Extend, Split, External geometry, Carbon copy, Toggle construction geometry

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• Sketcher constraints:
  • Geometric constraints: Coincident, Point on object, Vertical, Horizontal, Parallel, Perpendicular, Tangent, Equal, Symmetric, Block
  • Dimensional constraints: Lock, Horizontal distance, Vertical distance, Distance, Radius or weight, Diameter, Auto radius/diameter, Angle, Refraction (Snell's law)
  • Constraint tools: Toggle driving/reference constraint, Activate/deactivate constraint

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• Sketcher tools: Select unconstrained DoF, Select associated constraints, Select associated geometry, Select redundant constraints, Select conflicting constraints, Show/hide internal geometry, Select origin, Select horizontal axis, Select vertical axis, Symmetry, Clone, Copy, Move, Rectangular array, Remove axes alignment, Delete all geometry, Delete all constraints

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• 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, Show/hide B-spline control point weight, Convert geometry to B-spline, Increase B-spline degree, Decrease B-spline degree, Increase knot multiplicity, Decrease knot multiplicity, Insert knot, Join curves

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• Sketcher virtual space: Switch virtual space

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• Additional: Sketcher Dialog, Preferences, Sketcher scripting

User documentation

• Getting started
• Installation: Download, Windows, Linux, Mac, Additional components, Docker, AppImage, Ubuntu Snap
• Basics: About FreeCAD, Interface, Mouse navigation, Selection methods, Object name, Preferences, Workbenches, Document structure, Properties, Help FreeCAD, Donate

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• Help: Tutorials, Video tutorials
• Workbenches: Std Base, Arch, Assembly, CAM, Draft, FEM, Inspection, Mesh, OpenSCAD, Part, PartDesign, Points, Reverse Engineering, Robot, Sketcher, Spreadsheet, Start, Surface, TechDraw, Test Framework, Web

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• Addons: Addon Manager, External workbenches, Scripting and macros

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• Hubs: User hub, Power users hub, Developer hub