Incomplete article. It's a beginning, not yet a definitive guide or howto. I'm trying to take it there, but need to get my own ideas implemented fully before it can become a howto.
Add some cool sketches with anisotropic shading to show examples? Some painting styles will also have this relationship. Many sketching styles will have darker edges for sharper surfaces. I don't have a working digicam right now or I would draw some quick sketches with this kind of shading behavior.
At this point, I actually have none. I've thought a lot about edges but haven't made enough progress in understanding traditional multipass to begin piping output of the 3D scene analysis to a 2D post-process. Thus, any code you will have to add yourself or wait for...or help me learn multipass and how to use the compositor etc for post-processing