Yes, there are bones, but I don't use them (model isn't animated BTW).
I've converted example from AUM, where grass where reacting for player and moving randomly by faked wind.

Slin@ grass is highlighted (as well as trees), and yes, still from time to time I get low framerate.

Pappenheimer@ it's same jerking from 59-60, when I get in grass sometimes I get this 20-40 fps.

TechMuc@ thank you for offering your help, we'll see may be tomorrow I'll send it to you.