converting cycles textures to pbr maps

I am hoping that this is the correct place to post this.
I have used blender for quite a while and and have developed an interest in using blender to create assets for games. Making models is quite easy but things get messy when it comes to texturing.
I can create some decent textures using the node tree in cycles but is there a way to bake these textures into pbr maps for a game engine like unity 5 or unreal 4.
If this isnt possible (it probably isnt possible since they are completely different rendering engines) then how would you guys recommend i build pbr textures for games in a way that i can have one mesh with drastically different materials (some parts are metal others are plastic or rust and so on)