Normally, when you get the position of an object, you actually get the position of the object's center of mass. In most cases this is enough, but when the object's center of mass isn't the same as its geometric position, and you want to locate it (or locate something in it) geometricly, just "getting its position" won't cut it.

The trick is to take the vector returned by Get Position and offset it by half the total size of the object ("the offset"), with "total size" referring to the minimum and maximum vectors of the object, added together.

By extension, to set the geometric position of the object, set the actual position of the object to the desired position subtracted by the offset.