public void clear()
{
processChanges();
for( int i = bodyList.Count - 1; i >= 0; i-- )
removeBody( bodyList[i] );
for( int i = controllerList.Count - 1; i >= 0; i-- )
removeController( controllerList[i] );
for( int i = breakableBodyList.Count - 1; i >= 0; i-- )
removeBreakableBody( breakableBodyList[i] );
processChanges();
}