Also updated material densities and added attribute MaxPickDensity to pickaxe, so it's now possible to define a pickaxe that cannot go through granite.
Previously, smooth materials would get extra triangles at the top to create
slopes instead of steps. Now those also appear at the bottom.
Smooth also gets generally smoother at the bottom, while Rough gets rougher
at the top. The new Smoother material is somewhere between Flat and Smooth.
Octagon is like Flat but also gets straight slope triangles.
Sven Eberhardt