Simply draw on the surface below. Then press SPACE to extract the triangulation from your picture and embed it into Box2D and see what happen. Press ENTER to clean and play again.
The algo is fast and accurate for almost all pictures. It naturally manages holes and interlocked shapes.
How does it work ? Just few lines of code with the help of Daedalus Lib. Have a look to the wiki page if you need to be conviced !