GBRUnion - Cutlines Option

When the output geometry requires an island area there are several ways of creating the island. The preferred method varies depending on the output format and the target software.

  island formed by a cut line going into and back out of the shape and wrapping around the island.  

One way to form an "island" is to use a cutline. The shape's boundary basically goes into the shape and wraps around the island and goes out the same path. This is a common way to generate such islands in the GDSII data format.

Note: if you use cutlines for AutoCAD DXF output the resulting closed polylines cannot be extruded along the Z axis. Instead, use the butting option.