From FreeCAD Documentation
- To add features:
- Press the Add feature button.
- Select a feature in the Tree view or the 3D view.
- Repeat to add more features.
- To remove features:
- Press the Remove feature button.
- Do one of the following:
- Select a feature in the Tree view or the 3D view.
- Select a feature in the list and press the Del key.
- Right-click a feature in the list and select Remove from the context menu.
- Repeat to remove more features.
- If there are several features in the pattern, their order can be important. See PartDesign PolarPattern.
- Specify the mirror Plane:
- Vertical sketch axis: The Y axis of the sketch (the plane passes through this reference and the Z axis of the sketch, only available for sketch-based features).
- Horizontal sketch axis: The X axis of the sketch (idem).
- Construction line #: A separate entry for each construction line in the sketch (idem).
- Base XY plane: The XY plane of the Body.
- Base YZ plane: The YZ plane of the Body.
- Base XZ plane: The XZ plane of the Body.
- Select reference...: Select a planar face in the 3D view.
- If the Update view checkbox is checked the view will update in real time.