This command is used to subtract one or more polygon pour objects from another 'base' polygon pour.
With two or more existing polygon pours moved into overlapping position, this command is accessed from the PCB editor by selecting the 'base' polygon (the pour to be subtracted from), right-clicking then choosing the Polygon Actions » Subtract Selected Polygons command from the context menu.
First, ensure that new polygon pours are placed (or existing polygon pours dragged) so that they are overlapping a 'base' polygon - that is to be subtracted from. Then select this 'base' polygon.
After launching the command, you will be prompted to select the polygon(s) to be subtracted from the base polygon. Click on each required polygon (not the base).
Right-click, or press Esc to complete the process. The portion of each polygon overlapping the base polygon will be substracted from the base, resulting in a new, single polygon shape, that will present after repouring.
- If the Repour Polygons After Modification option is not enabled on the PCB Editor - General page of the Preferences dialog, you will need to repour manually to see the resulting single polygon.
- Subtracting polygons allows you to more easily create cutouts within polygon pours. Subtracting a polygon pour that is completely within the area of the base polygon will result in that pour becoming a polygon pour cutout region object.