Boolean cutters don't like sprites..that was my first idea..but early terminate of the render ended that chain of thought. The sprites are wrong just grabbed one off the cd for testing and the action was also done in haste as it wa getting late and I wanted to test the overall effect idea. Will clean it up and post as time allows. I often get these ideas right before I should be shutting down so they are often rough tests .
the boolean without sprites was going to expose a crumbled version simliar to this post..use imagination...
http://johnl.inform.net/pages/boolmorph.htm