So, as a graphics programmer directly working on mobile games, I haven't really played with the recent trend that I see everywhere regarding material layers, an example is Unreal Engine 4, and more specifically the following article:
http://www.unrealengine.com/files/downloads/2013SiggraphPresentationsNotes.pdf
I understand the need for this and it's awesome! What I haven't grasped yet is, is each layer a separate pass? Can someone explain this to me please?
Many thanks!