Mesh Formelement

From FreeCAD Documentation
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Einleitung

Ein Mesh Feature-Objekt (Mesh Formelement) oder formal ein Mesh::Feature ist ein einfaches Element mit einem ihm zugeordneten Mesh MeshObject (Mesh-Objekt), das in der 3D-Ansicht angezeigt werden kann.

Ein Mesh Formelement ähnelt konzeptionell einem Part Formelement; Ersteres ist das Basisobjekt für Elemente mit "Polygonnetz"-Information, während Letzteres das Basisobjekt für Elemente mit "geometrischer Form"-Information ist.

Bitte beachten, dass der Arbeitsbereich FEM ebenfalls Polygonnetze verwendet, aber in diesem Fall wird ein anderes Objekt verwendet, das FEM FemMeshObject genannt wird (Fem::FemMeshObject-Klasse). Dieses Objekt ist nicht von dem Mesh Formelement abgeleitet und hat andere Eigenschaften.

Vereinfachtes Diagramm der Beziehungen zwischen den Kernobjekten in FreeCAD.

Anwendung

Fast alle Mesh-Objekte, die mit den im Arbeitsbereich Mesh verfügbaren Befehlen erzeugt werden, sind Mesh Formelemente. Die parametrischen Mesh-Objekte, die mit dem Befehl Mesh RegelgeometrieErstellen erzeugt werden, bilden die einzige Ausnahme. Ein Mesh Formelement kann auch über die Python-Konsole erstellt werden, wie im Abschnitt Skripten beschrieben.

Das Mesh::Feature wird im Arbeitsbereich Mesh definiert, kann aber als Basisklasse für skriptgenerierte Objekte in allen Arbeitsbereichen, die 2D- and 3D-Netze erstellen, verwendet werden.

Ein Mesh::Feature besitzt einfache Eigenschaften, wie eine Positionierungund visuelle Eigenschaften, die die Darstellung seiner Kanten und Flächen bestimmen.

Eigenschaften

Siehe Eigenschaft für alle Arten von Eigenschaften, die skriptgenerierte Objekte besitzen können.

The Mesh Feature (Mesh::Feature class) is derived from the basic App GeoFeature (App::GeoFeature class) and inherits all its properties. It also has several additional properties. Notably a DatenMesh property, which stores its Mesh MeshObject. This is the geometry that is shown in the 3D view.

These are the properties available in the property editor. Hidden properties can be shown by using the Show all command in the context menu of the property editor.

Daten

Basis

  • Daten (Hidden)Proxy (PythonObject): a custom class associated with this object. This only exists for the Python version. See Scripting.
  • DatenMesh (MeshKernel): a Mesh MeshObject class associated with this object. It lists the number of Points, Edges, and Faces of the mesh.
  • DatenPlacement (Placement): the position of the object in the 3D view. The placement is defined by a Base point (vector), and a Rotation (axis and angle). See Placement.
    • DatenAngle: the angle of rotation around the DatenAxis. By default, it is (zero degrees).
    • DatenAxis: the unit vector that defines the axis of rotation for the placement. Each component is a floating point value between 0 and 1. If any value is above 1, the vector is normalized so that the magnitude of the vector is 1. By default, it is the positive Z axis, (0, 0, 1).
    • DatenPosition: a vector with the 3D coordinates of the base point. By default, it is the origin (0, 0, 0).
  • DatenLabel (String): the user editable name of this object, it is an arbitrary UTF8 string.
  • Daten (Hidden)Label2 (String): a longer, user editable description of this object, it is an arbitrary UTF8 string that may include newlines. By default, it is an empty string "".
  • Daten (Hidden)Expression Engine (ExpressionEngine): a list of expressions. By default, it is empty [].
  • Daten (Hidden)Visibility (Bool): whether to display the object or not.

Ansicht

Base

  • Ansicht (Hidden)Proxy (PythonObject): a custom viewprovider class associated with this object. This only exists for the Python version. See Scripting.

Display Options

  • AnsichtBounding Box (Bool): if it is true, the object will show the bounding box in the 3D view.
  • AnsichtDisplay Mode (Enumeration): Shaded (no edges), Wireframe (no faces), Flat Lines (regular visualization), Points (only vertices).
  • AnsichtShow In Tree (Bool): if it is true, the object appears in the Tree view. Otherwise, it is set as invisible.
  • AnsichtVisibility (Bool): if it is true, the object appears in the 3D view; otherwise it is invisible. By default this property can be toggled on and off by pressing the Space bar.

Object Style

  • Ansicht (Hidden)Coloring (Bool): it defaults to false.
  • AnsichtCrease Angle (FloatConstraint):
  • AnsichtLighting (Enumeration): One side (default), Two side; the illumination comes from two sides or one side in the 3D view.
  • AnsichtLine Color (Color): a tuple of three floating point RGB values (r,g,b) to define the color of the edges in the 3D view; by default it is (0.0, 0.0, 0.0), which is displayed as [0,0,0] on base 255, completely black .
  • AnsichtLine Transparency (Percent): an integer from 0 to 100 (a percentage) that determines the level of transparency of the edges in the 3D view. A value of 100 indicates completely invisible edges; the edges are invisible but they can still be picked as long as AnsichtSelectable is true.
  • AnsichtLine Width (FloatConstraint): a float that determines the width in pixels of the edges in the 3D view. It defaults to 1.0.
  • AnsichtOpen Edges (Bool): it defaults to false.
  • AnsichtPoint Size (FloatConstraint): similar to AnsichtLine Width, defines the size of the vertices.
  • AnsichtShape Color (Color): similar to AnsichtLine Color, defines the color of the faces. It defaults to (0.8, 0.8, 0.8), which is displayed as [204,204,204] on base 255, a light gray.
  • Ansicht (Hidden)Shape Material (Material): an App Material associated with this object. By default it is empty.
  • AnsichtTransparency (Percent): an integer from 0 to 100 (a percentage) that determines the level of transparency of the faces in the 3D view. A value of 100 indicates completely invisible faces; the faces are invisible but they can still be picked as long as AnsichtSelectable is true.

Selection

  • AnsichtOn Top When Selected (Enumeration): Disabled (default), Enabled, Object, Element.
  • AnsichtSelectable (Bool): if it is true, the object can be picked with the pointer in the 3D view. Otherwise, the object cannot be selected until this option is set to true.
  • AnsichtSelection Style (Enumeration): Shape (default), BoundBox. If the option is Shape, the entire shape (vertices, edges, and faces) will be highlighted in the 3D view; if it is BoundBox only the bounding box will be highlighted.

Skripten

See also: FreeCAD Scripting Basics and scripted objects.

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

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

import FreeCAD as App

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

For Python subclassing you should create the Mesh::FeaturePython object.

import FreeCAD as App

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