Play with light path node in Blender Cycles

Videofile: 

Using Blender's Light Path Node for Cycles

Ok... this Is a quite advanced technique and I posted mostly as a bookmark form Myself...

You will need this to control how the light will interact with your materials in your blender - cycles scene..

I'm gonna experiment with this settings mostly to achieve the "perfect" look for my upcoming short movie "Odysseus - Nobody" , but you could actually need even for your architectonic rendering ..

What we see in the real life are not objects themselves, but the refraction of the light on them ... so, think how this can be important in a 3d rendering engine, that is nothing else than the artificial recreation of our vision...

This tutorial, from blendercookie, is about the material node "light path node" ... If you ignore what is a node, I recommend you to start with some basic tutorials...