TechDraw LengthDimension

Description
The Dimension Length tool adds a linear dimension to a View. The dimension may be between the distance between two vertices, the length of one edge or the distance between 2 edges. The distance will initially be the projected distance (ie as shown on the drawing), but this may be changed to the actual 3D distance using the tool.



How to use

 * 1) Select the points or edge which define your measurement.
 * 2) Press the  button
 * 3) A dimension will be added to the View.  The dimension may be dragged to the desired position.

Limitations
Dimension objects are vulnerable to "topological naming" issues. This means that if you modify your 3D geometry the faces and edges of the model may be renamed internally; if a dimension is attached to an edge that is then modified, the dimension may break and not longer display the correct measurement value.

This means that in general it is not possible to keep the projected 2D dimensions synchronized with the actual 3D objects if the latter are modified. Therefore, it is recommended that dimensions be added towards the end of the model creation process, when the model is no longer being modified.

Data

 * : Horizontal position of the dimension text relative to the View.
 * : Vertical position of the dimension text relative to the View.
 * : Allows additional text to be added to the dimension text. Dimension value will replace %.2f (or other valid printf format specifier).
 * : Length,radius,diameter, etc. Not normally manipulated by the end user.
 * : "True" - based on 3D geometry or "Projected" - based on the drawing. Not normally manipulated directly by the end user.
 * : The amount by which the piece may larger than the Dimension shown.
 * : The amount by which the piece may be smaller than the Dimension shown.
 * : "True" - ignore actual value and display FormatSpec as value. "False" - use actual value.

View

 * : The name of the font to use for the dimension text.
 * : Dimension text size in mm.
 * : Dimension line weight.
 * : Color for lines and text.

Scripting
TechDraw API and FreeCAD Scripting Basics.

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