We integrate our Solid Geometry engine sgCore and Bullet physics Engine
For example, with sgCore you can build such object (one boolean operation):

and insert this object in your scene:
http://www.youtube.com/watch?v=83oDbOwN ... r_embedded
You can download Sources of this demo from our site - http://www.geometros.com/sgcore/tutorials/index.htm
Just for Windows only. Comming soon for iOS.