TechDraw LandmarkDimension: Difference between revisions

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# Select 2 Point objects in the [[Tree_view|tree view]] or the [[3D_view|3D view]].
# Select two point objects in the [[3D_view|3D view]] or [[Tree_view|Tree view]].
# Select also the View to which the dimension is to be added.
# Add the correct TechDraw View to the selection by selecting it in the [[Tree_view|Tree view]].
# There are several ways to invoke the tool:
# Press the {{Button|[[Image:TechDraw_LandmarkDimension.svg|16px]] [[TechDraw_LandmarkDimension|Insert Landmark Dimension - EXPERIMENTAL]]}} button or {{MenuCommand|TechDraw → Dimensions → Insert Landmark Dimension - EXPERIMENTAL}}
#* Press the {{Button|[[Image:TechDraw_LandmarkDimension.svg|16px]] [[TechDraw_LandmarkDimension|Insert Landmark Dimension - EXPERIMENTAL]]}} button.
# A dimension will be added to the View. The dimension text may be dragged to the desired position.
#* Select the {{MenuCommand|TechDraw → Dimensions → [[Image:TechDraw_LandmarkDimension.svg|16px]] Insert Landmark Dimension - EXPERIMENTAL}} option from the menu.
# A dimension is added to the View.
# The dimension may be dragged to the desired position.
# If needed, add tolerances as described on [[TechDraw_Geometric_dimensioning_and_tolerancing#Tolerances|this page]].


== Limitations == <!--T:7-->
== Limitations == <!--T:7-->

Revision as of 18:01, 27 July 2023

TechDraw LandmarkDimension

Menu location
TechDraw → Dimensions → Insert Landmark Dimension - EXPERIMENTAL
Workbenches
TechDraw
Default shortcut
None
Introduced in version
0.19
See also
TechDraw HorizontalDimension, TechDraw VerticalDimension

Description

The TechDraw LandmarkDimension tool adds a linear dimension to a View. The dimension is based on two point objects (Draft Point or Part Point objects) from the 3D model. Random vertices from a shape will not work.

The purpose of this tool is to provide a workaround to the corruption of dimensions caused by the "topological naming" issues. The source points should use Expressions or other containing mechanisms to establish their position. Since the points are Document Objects, and not shape components, their name does not change with recomputes, and hence they are easily found.

See TechDraw LengthDimension for more on dimensions and topological naming.

The Landmark Dimension generally behaves like any other Dimension.

Usage

  1. Select two point objects in the 3D view or Tree view.
  2. Add the correct TechDraw View to the selection by selecting it in the Tree view.
  3. There are several ways to invoke the tool:
  4. A dimension is added to the View.
  5. The dimension may be dragged to the desired position.
  6. If needed, add tolerances as described on this page.

Limitations

The Landmark Dimension tool is initially limited to "Distance" dimensions. Other types may be added if demand warrants.

Properties

Landmark Dimension does not introduce any new properties.

Scripting

See also: Autogenerated API documentation and FreeCAD Scripting Basics.

The Landmark Dimension tool can be used in macros and from the Python console by using the following functions:

dim1 = FreeCAD.ActiveDocument.addObject('TechDraw::LandmarkDimension','Landmark')
dim1.Type = "Distance"
dim1.References2D=[(TDView, 'Vertex1')]
dim1.References3D=[(Point3d1, 'Vertex1')]
dim1.References3D=[(Point3d2, 'Vertex1')]
rc = page.addView(dim1)