To Subtract AEC Polygons

Use this procedure to subtract AEC polygons from one another in order to create a hole in an AEC polygon. This would be useful, for example, for creating a complex pattern for a curtain wall infill.

To perform a subtraction operation, you need to select AEC polygons that intersect one another. You can choose whether to keep the subtracted AEC polygon in the drawing as a separate unit. For example, you may want to keep the AEC polygon if you need to subtract the same shape from other AEC polygons.

1. Create an AEC polygon from which to subtract a hole.
2. Create a second, smaller AEC polygon to represent the area to be subtracted from the larger AEC polygon.

   You can draw the second AEC polygon within or overlapping the area of the first AEC polygon, or you can draw it in another location and then move it onto the larger AEC polygon.

3. Select the larger AEC polygon.
4. Click AEC Polygon ribbon contextual tab Modify panel Subtract.
5. Select the smaller AEC polygon to subtract from the larger AEC polygon.
6. Enter y (Yes) to erase the subtracted AEC polygon, or n (No) to leave the AEC polygon in the drawing.