Purely Node Based Materials A while ago, I was searching for a leather texture online, when I came across a thread on Blender Artists where someone had made an extremely respectable leather texture with just Blender nodes. This was the result on the material preview sphere:



The only actual texture they used was a Wave texture. The rest was just Mapping nodes and other assorted math and vector converters. The person included two screenshots, from which I reproduced created the described node setup. The one modification I made was to add a Mapping node immediately after the Texture Coordinates node because I needed the texture for an elongated cylinder at the time. Here are the two shots:



Main setup.



Leather node group.

My question is: How does this node setup actually work, and could the logic be employed to make other textures? Does anyone know of other examples that exist or could be created (would love to see them)?

Also, as I realize this could be a pain to create (it was for me), I am including a .blend file with the node setup and some other gizmuhwhichets that I built at the time.
Does anyone know of other examples that exist  


blendswap have alot of those procedural materials,
some examples:
-procedural wood
-procedural leather
-fabric
-clouds
-polystyrene
-metal