There is a way, Russ, but it's not perfect. I would like to have an 'angle shader' that can be softened to cover a whole mountain side, instead of all tiny sides within, say, a northern slope. The latter can be obtained by using a 'get normal (in texture)' and a 'convert blue' or 'red to scalar'. Adding a 'rotate Y vector' for , well, rotation of that normal.