Not sure how well it works in UE4 or if we even have something like this in UE4 but touch bending vegetation is nothing new, Crysis 3 and the old Cryengine 3 had this implement as a standard feature. Back in the days they handled it like in this tutorial…https://youtube.com/watch?v=L0fD_CCbjnI
Something similiar like this in UE4 would be nice.