Hair dynamics does not affect all grass stands, some are frozen I'm using hair dynamics to simulate grass blowing in the wind. When hair dynamics is activated, some hairs do not move at all. About 1-2% stand still. I don't understand and cannot find a explanation for this after searching the net. Hope someone here can advise?
I fixed the problem by deleting the emitter and particle system and re-creating it. When I made my emitter more complex (not a flat plane) and added more hairs it all worked fine.