Part Part2DObject

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Einleitung

Ein Part Part2DObject, oder formal ein Part::Part2DObject, ist ein einfaches Element mit einer topologische Form, das in der 3D Ansicht angezeigt werden kann.

Das Part::Part2DObject ist von einem Part Feature abgeleitet, ist aber auf 2D Geometrie spezialisiert, da seine Form auf einer Ebene liegen wird. Diese Ebene wird durch die Eigenschaft Daten-EigenschaftPlatzierung definiert (Position, Normale und Rotation). Die Ebene kann aber auch durch unterstützende geometrische Elemente definiert werden, wie z.B. die Ebene, die durch drei beliebige Eckpunkte erzeugt wird, oder eine Fläche eines Volumenkörpers.

Vereinfachtes Diagramm der Beziehungen zwischen den Kernobjekten im Programm. Die Klasse Part::Part2DObject ist auf 2D Formen spezialisiert, so dass sie die Basisklasse für planare Objekte ist, die mit den Werkbänken Draft und Sketcher erstellt werden. Sie enthält eine Erweiterung, mit der sie an Flächen und Ebenen angehängt werden kann.

Kurzanleitung

The Part Part2DObject is an internal object, so it cannot be created from the graphical interface, only from the Python console as described in the Scripting section.

The Part::Part2DObject is defined in the Part Workbench but can be used as the base class for scripted objects in all workbenches that produce 2D geometrical shapes. For example, it is the base object for sketches (Sketcher SketchObject), and for most objects created with the Draft Workbench.

Workbenches can add more properties to this basic element to produce an object with complex behavior.

Properties

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

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

In addition to the properties described in Part Feature, the Part Part2DObject has the following properties in the property editor.

Data

Attachment

DatenMap Mode (Enumeration): Deactivated by default. This property determines a plane which the object will use as reference for 2D geometry. Clicking on the ellipsis ... (three dots), to the right of the entry field opens the Part Attachment task panel that allows selecting the supporting plane by picking different elements in the 3D view. The different modes are: Deactivated, Translate origin, Object's XY, Object's XZ, Object's YZ, Plane face, Tangent to surface, Normal to edge, Frenet NB, Frenet TN, Frenet TB, Concentric, Revolution section, Plane by 3 points, Normal to 3 points, Folding, Inertia 2-3, Align O-N-X, Align O-N-Y, Align O-X-Y, Align O-X-N, Align O-Y-N, Align O-Y-X.

See Part Attachment for more information on all mapping modes.

The following two properties are normally hidden. They become visible once DatenMap Mode is something other than Deactivated.

DatenMap Reversed (Bool): it defaults to false; if it is true the Z direction will be reversed. For example, a sketch will be flipped upside down.
DatenAttachment Offset (Placement): the position of the object in the 3D view, with respect to the attachment object's placement. The placement is defined by a Base point (vector), and a Rotation (axis and angle). See Placement.

Hidden properties Data

Attachment

DatenAttacher Type (String): class name of the attach engine object driving the attachment. It defaults to Attacher::AttachEnginePlane.
DatenSupport (LinkSubList): it is the plane or face supporting the 2D geometry. It defaults to an empty list [].
DatenMap Path Parameter (Float): sets point of curve to map a sketch to. It goes from 0 to 1, which corresponds to the start and end. It defaults to 0.

View

Grid

AnsichtGrid Size (Length): the size of the spacing of the local grid lines in the 3D view; it defaults to 10 mm.
AnsichtGrid Snap (Bool): it defaults to false; if true the grid can be used to snap points.
AnsichtGrid Style (Enumeration): the style of the grid lines; Dashed (default) or Light.
AnsichtShow Grid (Bool): it defaults to false; if true a grid local to the object will be displayed in the 3D view. This grid is independent of the Draft grid.
AnsichtTight Grid (Bool): if true (default) the local grid will be localized around the origin of the shape, otherwise it will extend itself more.

Hidden properties View

All other view properties, including hidden properties, are those of the base Part Feature object.

Scripting

See also: FreeCAD Scripting Basics, and scripted objects.

See Part Feature for the general information on adding objects to the program.

A Part2DObject is created with the addObject() method of the document.

import FreeCAD as App

doc = App.newDocument()
obj = App.ActiveDocument.addObject("Part::Part2DObject", "Name")
obj.Label = "Custom label"

This basic Part::Part2DObject doesn't have a Proxy object so it can't be fully used for sub-classing.

Therefore, for Python scripting, the recommendation is to create the Part::Part2DObjectPython object.

import FreeCAD as App

doc = App.newDocument()
obj = App.ActiveDocument.addObject("Part::Part2DObjectPython", "Name")
obj.Label = "Custom label"

For example, most tools from the Draft Workbench, like Draft Line, Draft Rectangle, Draft Polygon, etc., are Part::Part2DObjectPython objects with a custom icon and additional properties.