TechDraw LinkDimension

Description
The Dimension Link tool creates a link between 3D geometry and 1 or more Dimensions on a Page. This link allows the Dimension to use actual 3D values instead of 2D projected values.

How to use

 * 1) Create your dimension on the drawing page as usual.
 * 2) Select the geometry in the 3D view, for example, an edge, that corresponds to one of your dimensions.
 * 3) Press the  button.
 * 4) A dialog will open. Select one or more Dimensions to be linked to the selected 3D geometry.
 * 5) Press.

Limitations
Dimension objects are vulnerable to "topological naming" issues. See the information in the TechDraw Dimension Length tool for more information. It is recommended that linking dimensions be one of the last steps in your process.

The link tool will not stop you from making illogical links, so you need to choose the correct edge from the 3D view when creating the link.

There is currently no way to break a link; you can change the back to  and the dimension will use the projected value instead of the linked  value.

Properties

 * 1) The MeasureType property of a linked Dimension will be changed from "Projected" to "True".

Scripting
TechDraw API and FreeCAD Scripting Basics.

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