How to use UE4 terrains brush in game?

I’m trying to create the brush you see in the editor but during the game.I don’t want to actually create the functionality of the brush just the look as I move my mouse over different terrain. Basically this but I would obviously change a lot of the look , just looking for a place to start.

Thanks in advance!

A decal would probably be the best starting point. Add some mouse-to-world position logic, and you should have something useful.