Questions about engine

Hi everyone,
I would ike to say UE is an amazing Game Engine, i have developed a few Academic projects for my University. and now for my graduation and as a challenge for me, i’ve decided to develop a mini game engine, i’ve reseach UE uses PhysX as Physis Engine, and i have adapted to my mini engine and my question is wich animation SDK does UE4 use ?, principal goal is to simulate the aim-offset to make a FPS game, maybe it is a Inverse kinematic or it is Blending animation, thank you all

UE4 uses its own custom-written animation system. Also as a side-note: the engine can be compiled without PhysX.