Mesh Feature/it

Introduzione
A Mesh Feature object, or formally a, is a simple element with a mesh object associated to it that can be displayed in the 3D view.

A Mesh Feature is similar conceptually to a Part Feature; the former is the base object for elements with "mesh" information, while the latter is the base object for elements with "geometrical shape" information.

Please note that the also uses meshes, but in this case it uses a different object, called Fem FemMeshObject ( class). This object is not derived from Mesh Feature so it has different properties.



Utilizzo
The Mesh Feature 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 is defined in the Mesh Workbench but can be used as the base class for scripted objects in all workbenches that produce 2D and 3D meshes.

A has simple properties like a placement, and visual properties to define the appearance of its edges and faces. Workbenches can add more properties to this basic element to produce an object with complex behavior.

Properties
A Mesh Feature ( class) is derived from the basic App GeoFeature ( class), therefore it shares all the latter's properties.

In addition to the properties described in App GeoFeature, the Mesh Feature has the property, which stores the Mesh MeshObject of this element; this is the geometry that is shown in the 3D view.

Other properties that this object has are those related to the appearance of its Mesh MeshObject, including, , , , , , , and also the hidden property.

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

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

Data

 * : a Mesh MeshObject class associated with this object. It lists the number of, , and of the mesh.
 * : the position of the object in the 3D view. The placement is defined by a point (vector), and a  (axis and angle). See Placement.
 * : the angle of rotation around the . By default, it is (zero degrees).
 * : the unit vector that defines the axis of rotation for the placement. Each component is a floating point value between and . If any value is above, the vector is normalized so that the magnitude of the vector is . By default, it is the positive Z axis,.
 * : a vector with the 3D coordinates of the base point. By default, it is the origin.
 * : the user editable name of this object, it is an arbitrary UTF8 string.

Hidden properties Data

 * : a list of expressions. By default, it is empty.
 * : 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.
 * : a custom class associated with this object. This only exists for the Python version. See Scripting.
 * : whether to display the object or not.

View
Most objects in FreeCAD have what is called a "view provider", which is a class that defines the visual appearance of the object in the 3D view, and in the tree view. The default view provider of Mesh Feature objects defines the following properties. Scripted objects that are derived from Mesh Feature will have access to these properties as well.


 * : if it is, the object will show the bounding box in the 3D view.
 * : (no edges),  (no faces),  (regular visualization),  (only vertices).
 * : (default), ; the illumination comes from two sides or one side in the 3D view.
 * : a tuple of three floating point RGB values to define the color of the edges in the 3D view; by default it is, which is displayed as  on base 255, completely black.
 * : an integer from to  (a percentage) that determines the level of transparency of the edges in the 3D view. A value of  indicates completely invisible edges; the edges are invisible but they can still be picked as long as  is.
 * : a float that determines the width in pixels of the edges in the 3D view. It defaults to.
 * : (default),, ,.
 * : it defaults to.
 * : similar to, defines the size of the vertices.
 * : if it is, the object can be picked with the pointer in the 3D view. Otherwise, the object cannot be selected until this option is set to.
 * : (default), . If the option is, the entire shape (vertices, edges, and faces) will be highlighted in the 3D view; if it is  only the bounding box will be highlighted.
 * : similar to, defines the color of the faces. It defaults to , which is displayed as on base 255, a light gray.
 * : if it is, the object appears in the tree view. Otherwise, it is set as invisible.
 * : an integer from to  (a percentage) that determines the level of transparency of the faces in the 3D view. A value of  indicates completely invisible faces; the faces are invisible but they can still be picked as long as  is.
 * : if it is, the object appears in the 3D view; otherwise it is invisible. By default this property can be toggled on and off by pressing the bar in the keyboard.
 * : if it is, the object appears in the 3D view; otherwise it is invisible. By default this property can be toggled on and off by pressing the bar in the keyboard.

Hidden properties View

 * : it defaults to.
 * : a custom view provider class associated with this object. This only exists for the Python version. See Scripting.
 * : an App Material associated with this object. By default it is empty.

Scripting
FreeCAD Scripting Basics, and scripted objects.

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

A Mesh Feature is created with the method of the document.

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

Therefore, for Python subclassing, you should create the object.