[>BKA< T Wrecks]

No, I suppose not. Basic overviews are done like I described in the thread I linked, even multi-level ones. The more multi-level stuff and eye candy, the more Photoshop is involved, of course.

To get the different slices, all you do is go into overview perspective and change the Zmin value. Then you take screenshots at the desired height levels, and finally you photoshop them all together.
But the height in the overview.txt file is always the Zmax value, not Zmin.