In this post I will demonstrate three AutoCAD commands related to AutoCAD regions: INTERSECT, SUBTRACT and UNION. In a previous post I introduced the AutoCAD region command. I have also already introduced other basic AutoCAD commands, such as e.g. AutoCAD POLYGON, AutoCAD SPLINE, AutoCAD XLINE etc.

I will be working with the following object:

I first enter the UNION command and select the entire geometry object displayed in above figure. I press ENTER and receive the following result:

If I instead choose the INTERSECT command and select the first two circles then I will get the following results – only the intersection between the two circles remains:

If I instead use the SUBTRACT command and first select the first circle, press ENTER, and then select the second circle and press ENTER, the following result is displayed:

For the drawing displayed in above figure I now use the UNION command on the remaining sequence of circles. After that I change to 3D mode in AutoCAD. This is what you will see:

I can now e.g. use the EXTRUDE AutoCAD command on the two regions that were returned by the SUBTRACT and UNION AutoCAD commands.

This completes my introduction to the SUBTRACT, UNION and INTERSECT commands in AutoCAD. In other posts I e.g. introduce pyautocad, a module for developing Python scripts for AutoCAD.

Linnart Felkl

Data scientist focusing on simulation, optimization and modeling in R, SQL, VBA and Python