The Opening Section boundary can be exported from Unwedge to a DXF file (AutoCAD Drawing Exchange File) using the Export DXF option. To do this:
Make sure the Opening Section View is selected.
Select Export DXF from the Export sub-menu of the File menu.
You will see a Save As dialog. Enter a name for the DXF file and select Save. The coordinates of the Opening Section boundary will be saved to a DXF file.
The Opening Section boundary can also be imported from a DXF file into Unwedge, using the Import DXF option.