In this tutorial i will show you how to create a simple flag in blender, & how to simulate it in Unreal Engine.
NOTE: In this tutorial i use a PLANE, if you want your flag to be 2 sided, use a cube.
https://dev.epicgames.com/community/learning/tutorials/Xm6P/unreal-engine-how-to-create-cloth-in-blender-simulate-a-flag-in-ue