my solution is straight-forward. It is the same technique
as in the old editor, I just had the wrong values. And
smoothing simply didn't work.

we need to know the normals that equate to the 18 sides in
Godwin's diagram:

http://ar2.eclipsemods.com/godwin/faces.gif

It doesn't matter if this isn't how normals are really
done, it is dictated by how you guess the facings of a
voxel.

We need:

bottom -
top -
left -
right -
front -
back -
back, top, left -
back, top, right -
back, bottom, left -
back, bottom, right -
front, top, left -
front, top, right -
front, bottom, left -
front, bottom, right -
left, top -
left, bottom -
right, top -
right, bottom -

Now I know this isn't perfect, but it based upon the
technique for guessing facings of voxel models, not on the
actual method used by WW. A more accurate model with
better granularity can be developed for those importing
from a polygon model.