Foliage collision + foliage bend on collision- In engine feature?

[CommunistSquared]

@;91355

Just gave it a quick try and came up with this simple material. It’s using the UVs green channel to prevent the grass base from being moved away. There are 2 parameters to adjust radius and strength of the bending effect.

GIF: http://abload.de/img/grassbent01a7bs0q.gif

I got this to work, but does anyone know how I could possibly modify it to keep the grass in the bended position for some time (or permanently)?