Thanks, it's appreciated, and I also found your shaders on sharecg.

However it takes a little too much time for me search and go through all this, since in the end I want to do quite different things, so I assume the relevant node I am looking for is the Fresnel Node?

Actually I think I misunderstood the Fresnel slighly and wasnt aware that it really already does give a light angle dependent shade.

But why does the ToonBsdf not render in Firefly when I connect it directly to the CyclesSurface Surface input like mentioned above?

I want to keep the basic toon shaders a simple as possible, cause in the end I want a hybrid look where a lot of other stuff goes into the flat materials and the toon is just for making a "posterize" effect and outline.

So I try to avoid cycles if possible since the structure gets large quickly, and especially since I have this bug where the modules jump around on screen...

I also missed the LightPath module, so, can you also use this with the PoserSurface Node? oder Do you need to use CyclesSurface when you use this?

I am a little bit confused which modules and renderers are compatible and which are not.