Recently RayforC4D had an update to version 1.9b that included the V-Ray Layered Shader.

You can now layer together materials and textures to make more complex surfaces fir V-Ray rendering. The thing is, that it is not entirely intuitive. Here Josef Bsharah provides an overview for using the new V-Ray Layer Shader within Cinema 4D, getting you oriented in creating layered materials for your renders.