Sketcher External

From FreeCAD Documentation

Sketcher External

Menu location
Sketch → Sketcher tools → Create external geometry
Default shortcut
Introduced in version
See also
Sketcher ConstructionMode


The Sketcher External tool projects edges and/or vertices belonging to objects outside the sketch onto the sketch plane. The projected geometry is called "external geometry". It stays parametrically linked to its source objects. External geometry edges are marked with a dedicated color (default magenta) and (introduced in version 1.0) linetype. Similar to construction geometry, external geometry is not visible outside the sketch, it is intended to help define constraints and other geometry inside the sketch itself.

The two magenta lines are external geometry linked to edges of a pre-existing Pad. They are used to constrain the circles.


See also: Drawing aids.

  1. There are several ways to invoke the tool:
    • Press the Create external geometry button.
    • Select the Sketcher → Sketcher tools → Create external geometry option from the menu.
    • Right-click in the 3D view and select the Create external geometry option from the context menu.
    • Use the keyboard shortcut: G then X.
  2. The cursor changes to a cross with the tool icon.
  3. Select an external edge or a vertex. See Notes.
  4. External geometry is created.
  5. This tool always runs in continue mode: optionally keep selecting external edges and/or a vertices.
  6. To finish, right-click or press Esc, or start another geometry or constraint creation tool.


  • Only edges and vertices from objects within the same coordinate system can be selected. The sketch and the object must be in same Body, or the same Part, or both in the global coordinate system. Use a Binder to bring a copy of the object into the current coordinate system if required.
  • Circular dependencies are not allowed. You cannot link to an object that depends on the sketch itself.
  • Links to elements from other sketches are possible, and encouraged, as they are more reliable than links to generated (solid) geometry. The latter can suffer from the Topological Naming Problem. See Advice for stable models.