Material: Color dependent on actor rotation

[Rapscallion]

[SOLVED] Changing property in Vector Transfor nodes from World to Local worked.

Okay, so basically I want to create a material which color will be dependent on actor rotation, to be more specific I want "simple" thing: all horizontal surfaces should be black and all vertical should be white. I have started with something which is visible below. It works, but only "once" - at the creation of object. The problem is that the colors aren't changing when I rotate the actor. Anyone knows how to achieve mentioned effect?