I've been trying to develop a camera based shader where half of the area of an object is in one color and the other half of is in another. It has to function the same way after a deformation, which is where the issue is. I've drawn some sketches to demonstrate what I'm imagining: The rotations in this image would happen as deformations, not as object rotations.
In the associated blend file I've put my best attempts and a mockup of how this would work:
The issue with this mockup is that I've had to create a separate material and a ghost camera to go along with it. This is no good because I'd like to have just one material that I can put on any shape.
Since I'd like to use this for characters it might be better to to base it on the UV map instead of the normals? They already have a direction built into them. Like so: I also tried this theory with Greater Than/Less Than nodes but I can't figure out the mathematics for it.