I would like to apply the outline that the toon material produces on my entire scene without having to link it to all my materials.
Is it possible to just apply the toon material to all the materials I have already set automatically (manually this would take a very long time), OR can I take a render where it only shows the toon material lines?
The properties there matches the toon material properties, and this section acts like a global toon material.
In fact what really happens is exactly the opposite. The contours effect in V-Ray is a post effect. The toon material only enables selective application of this post effect - e.g. it is a local override the global post effect
Sidenode:
the material is improperly named “toon”. The name was chosen only because it was named this way before the global “contour” effect exists. The correct name would be “contour override material”. However that would make a lot of people pass over it.