Sketcher External

Description
This tool pulls solid line geometry into your current sketch. Once these lines are pulled in, they will appear as magenta lines in the current sketch, and you can constrain and dimension sketch curves to them.

This is useful because it lets you constrain you sketch back to nearby solid edges.

You can ONLY pull in lines and edges that are on the same plane as the sketch plane. Only solid lines/edges can be pulled into the sketch, NOT 2D sketches or draft lines.

One can use this to dimension one sketch off of another using the following order of operations:
 * 1) Make sketch#1
 * 2) Pad or extrude it to make a solid, solid#1
 * 3) Make sketch#2 on the same plane as sketch#1
 * 4) Pull in solid#1 lines into sketch#2
 * 5) Pad or extrude sketch#2 to make solid#2



Use

 * Start a sketch to the previously selected face of a solid.
 * Activate the tool External Geometry.
 * Select, on the object existing, the line (segment or curve) that you will use.

In the sketch appears a new magenta line.

External Geometry can be used in a similar way to a Contruction line, for example to produce symmetries or parallels.

Example
The magenta lines are External Geometry selected on two objects of the same extrusion products with previous sketch. In this case they are used to create the constraints of tangency with the circumferences. The line on the smaller rectangle is not used. The active sketch with the basic forms hidden and external geometries visible.

When the sketch is closed, External Geometry lines are not visible.