[femm] What happens with 0 side length for blocks?

[istokesrees@xxxxxxxxxxx]

I have worked out how to specify mesh size using the 3 controllable
elements:
i) Max degrees per segment
ii) Element size along line
iii) Block Property side length

And I see how the size of the circle around the block property point
indicates
the approximate size of the mesh (or at least the relative mesh size
for that
block), however I don't know how to "expect" what specifying zero will
do.

Obviously, seeing the mesh is the easiest solution, but I'd still be
interested
to know what it is doing. Simply using some default?

On another note, I don't understand when you would define Nodal
Properties -
wouldn't field or current density only ever apply to regions? Or does
this
allow an arbitrary specification of some field or current distribution?

Thanks,

Ian.