Let’s merge 2D and 3D together! In this lesson, you will see different possible workflows to combine the power of Unreal Engine with the spontaneity of 2D animation. You will have the opportunity to do several practice exercises, like creating 2D FX or using Decals to create fake 2D shadows.
https://dev.epicgames.com/community/learning/talks-and-demos/v7X1/odyssey-2d-animation-in-unreal-engine-day-3