Not sure I fully understand the question. Are you looking for a program to automatically do this for you? If so, and you find one, it sure would be nice
If your looking for a program for you to do this with, I use Sketchup with a plugin from here http://www.phlatforum.com/viewforum.php?f=97
Works GREAT. As most foamies mostly contain larger pieces it is a rather easy process to maximize the foam sheets.