Draft Dimension

Description
This tool asks the user for two points defining the segment to be dimensioned, then a third point to locate the dimension line.



Dimension types available

 * Linear dimensions: by picking any 2 points or any straight edge with pressed.
 * Horizontal/vertical dimensions: by pressing after the first point is selected.
 * Diameter dimensions: by picking a curved edge with pressed.
 * Radius dimensions: by picking a curved edge with pressed, then pressing.
 * Angular dimensions: by picking 2 straight edges with pressed.

Usage

 * Pick 3 points on an empty area of the 3d view, or on an existing object.
 * Pressing will snap your point to available snap locations.
 * Pressing will constrain the dimension horizontally or vertically, or, when working on a circular edge, switches between diameter and radius modes.
 * Enter numbers to manually insert a coordinate.
 * Pressing will cancel the operation.
 * Pressing before the first point allows you to choose an edge to measure.
 * An option on the draft command bar allows you to draw several dimensions on one same line.

Constrained dimensions
By picking an existing edge with, the dimension will remember which edge it is bound to. If the endpoints of that edge move later on, the dimension will follow. This is also true for radius and diameter dimensions.