If by "of the shelf" you mean the libraries that are in the SDK to draw and texture polygons then yes.  

Just saying, theres a lot ignorance in this thread. The engine switch will increase development speed. FF13 ( FF13 only took 2 years to develop, rest was engine) and 14 spent long amounts of time in development but half that time was spent developing the engine along side the game.

Another obligatory bitch and whine about SE thread, even in light of them making a smart move.

ugh they made their own engine and now they use another one instead?

It's not so much that them switching to a third party engine is a bad move, it's just mind blowing how Square has been developing games.  This is their second failed engine and between this and the crystal tools, have probably lost them serious cash.  Enough cash that Tomb Raider and Hit Man selling higher than they ever have, haven't been able to cover the costs.

I thought SE has their own enigne?

They have a bunch of them. But aparently they decided UE4 was better. I am sure they will add a lot of their own tech to it tho.

They do! 

History lesson:

Since the PS1 days SE has developed a new egine for every installment to FF. Hell,most Japanese developers did this and it wasnt untill last gen that reusing engines caught on there. SE knows that their game development nowadays has been slowed by this tradition so their ditching it. Notice how a few Japanese developers are using UE4... Its to jump right in to development and cut time and cost.

'off the shelf' as for example the pre-built unreal engine that you license from another company to use.

Yeah, Square Enix, and most Japanese Devs, never did.  They'd technically build the engine with every game.

So no Source Engine switch?