Hi: could anybody explain how
 

Hi:
could anybody explain how to use the BoxToCell?
it is from example of dam breaking:
boxToCell
{
box (0 0 -1) (0.1461 0.292 1);
}
and my question is what does (0 0 -1) (0.1461 0.292 1) these two special point mean in this case? it seems that they were not the two endpoint of specified diagonal line?and how to ues it?
by the way,could anyone tell me how to patch a 3D circle cylinder zone in the field?
thanks!