Thanks Daniels118!
I've tried this many times in the past months.
Probably I've not tried hard enough. I will keep trying, fail and learn. [:-/]
The plugin I working for intend to be an three actions plugin.
At least two of them have to use the boolean operations.
I've found at least 3 different libraries specialized for this.
The best results was with commons-geometry 1.0 when was used as jar library in an stand alone application.
Using sources in the same context have more poor results.
Using this library into a plugin make the plugin relatively huge(1.6Mb) comparing with actual 153kb.
On all the cases the problem is the input data (vertices values of objects).
The resulted object will need have the values like it's position is at zero center but we will see it let say at x: 1.2m /y: 2.3m /z: 0.6m
based on where the selected furniture are.
Probably the CopyAsNewFurniture plugin hide the solution. I will see.