There are three Boolean operation defined in CAD: Union; Subract; Intersect.

How to access GC_BOOLOP in GstarCAD

* When using 2D Drafting workspace, find Home > Modify > Boolean (GC_BOOLOP), shown as below,

* When using GstarCAD Classic workspace, find Modify > Pline Boolean, shown as below,

* Or just enter GC_BOOLOP command, shown as below,

After executing the command, the following Boolean Operation Option dialog box will pop up,

Union:

With Union option, you can combine the total volume of two or more mass elements into a composite object.

Intersection:

With Intersection option, you can remove the common area of one mass element from another.

Subtraction:

With Subtraction option, you can remove non-overlapping portions and create a composite solid from the common volume.

Sometimes, users are unable to successfully generate regions, the reasons probably are possible intersection or unclosed objects.

Step-by-step tutorial: How to use GC_BOOLOP command

Select the option “Union” and uncheck the “Delete the second selected entity”, shown as below,

Select the exterior circle and then the small circles around it, it will keep all small circles around enabled for the next operation and you will get the first polyline as shown below,

Start again the Boolean operation, select option “Subtraction” and check “Delete the second selected entity”, as shown,

Then select the interior circle and then the small circles around it, then the small circles around it will be automatically deleted and you will get the final result as shown below,

Please note: it may be easier for you to hide some of the objects during your operation.