I'm working on a workflow to make duotone illustrations. I like to work with emission shaders for this, because they eliminate all lightbounces, thereby it requires almost no rendertime and gives me a vector-like illustration. In the image below I put a Fresnel Node in the Mixshader to seperate colors, but what I actually want is to replace this Node for the information of the lighting in the scene. Got any ideas?
I also tried to use a Toon node and a Glossy node with roughness to 0, but I really like the Emission shader because the color isn't affected by background or lighting. Maybe there is a way to convert a material node to color data and to set a colorramp on that?