cmNodes plugin is a free node based shader system plugin for Cinema 4D.
You can see similar in 3D Studio Max and Blender and in various compositing
software out there.
Why is it useful? Propably you have to use same effect on other channel
like bump map effect on diffusion or copy channel again and again with
Cinema 4D native material editor. Often this kind of repetitive
workflow makes shader work slow and tedious after hundreds of repetitions.
CmNodes will save you time when you can just checkmark any new
channel then just wire the node it where you want it to be copied.
This kind of referencing will save a lot of time in your shader
cmNodes textures examples
I made a custom layout for cmNodes which makes it easier to create new textures
and drop them onto shader window much faster.