A Boolean object combines two objects by performing a Boolean operation on them. In 3ds Max, a Boolean object is made from two overlapping objects. The original two objects are the operands (A and B) and the Boolean object itself is the result of the operation.

The fence is operand A, and the cat is operand B.

Upper left and right: A minus B

Second to upper left: B minus A

Second to lower left: Union

Lower left: Intersection

For geometry, the Boolean operations are:

• Union: The Boolean object contains the volume of both original objects. The intersecting or overlapping portion of the geometry is removed.
• Intersection: The Boolean object contains only the volume that was common to both original objects (in other words, where they overlapped).
• Subtraction (or difference): The Boolean object contains the volume of one original object with the intersection volume subtracted from it.