How would you make a realtime toon edge using ramps?
I want to make an outline that is variable width and doesn’t require double the geometry.
If ramps don’t work, is there another way of doing this, besides the double mesh version?
Maybe you can find something useful here.
Captain Oblivion provided a nice node setup (comment #5).
If you use glsl, you can make a node shader, and plug the mesh normals into a ramp shader, which when set to the right settings and combined with the diffuse color, makes an outline- something like the attachment. It’s a bit hacky, and only works on smoothed meshes, but it usually gets the job done.
Nice model btw 
This is what I got with that technique.
Attachments
you need to make the lines thicker by adjusting the colour ramp so that there is more black then transparent, in the node setup.