Btw. - realtime raytracing doesn't exist in any full fledged game engine yet.
Upcoming BRIGADE can do the trick:
But notice the specs; two powerful NVidia desktop graphics cards; and still, the performance sucks. But it's definitely the future.
I'm educated 3D animator, so I'm looking very much forward to realtime raytracing.
But there's another solution; voxel-cone raytracing. This SHOULD have existed in Unreal Engine 4, but was taken out, due to performance issues on latest generation consoles (XBox ONE and PlayStation 4). UNITY can do it, however, so it IS coming, and when it does, it's gonna be an important step towards true raytracing.
The solution that's used now, in all modern 3D engines, including Unreal Engine 4 and CryEngine, is called screen spaced reflections. Sure, they look ok, as in they're a huge step over plan texture baking which was modern 10 years ago; but now, the time is coming for raytracing.