With V-Ray for Unreal you get the best of both worlds - real-time and ray tracing. These video tutorials will get you started in no time. Step-by-step tutorial breakdowns and assets are available.
This video tutorial covers the basic workflow for rendering a simple scene with V-Ray for Unreal.
This tutorial demonstrates the basic workflow of importing a vrscene file and rendering from Unreal Engine with V-Ray for Unreal.
This Video with go over some advanced material workflows including vrscene materials as well as materials created outside Unreal Engine.