This node setup allow you to offset your normal pass on the X,Y,Z axis. It could be use for several cases (relighting is one of them for sure, so I thought I would share this node. All you have to do, is to “Append” this node in your blend file and your are done. It use a normal pass as input, and would output the new normal pass.
I received a mail the other day from Martins Upitis, who asked me really nicely if he could use my Cubic Lens Distortion Shader code into one of his GLSL shader. He was asking me if he could copy & tweak it a little bit. That was really funny to me since Martins is probably the guy who made me wants to learn shader in the first place after seeing one of his first shader he posted on blenderArtist, and also because he didn’t figure I was the same person asking him thousand of noobs questions on that same forum :p .
Of course I was so proud that I said yes, and he made it look so coooolll !!!
His shader create vignetting, chromatic aberration, cubic distortion, depth of field, and a really smart animation texture based on 1bit alpha store in each RGBA channels (which gives a lot of frames – so smart)… it looks really great !