I'm using the Terrain Assets package from the resources page ( http://unity3d.com/support/resources/ ), trying to use the fern object as a plant with the terrain paint tool. The problem is that the entire fern object moves and flows around. It doesn't stay put; it isn't planted.
How do i fix this?
Thanks!
Unislash
You have your fern set to the grass render mode, which is why you get that "unplanted" swaying motion.
- Bring up your fern's details. It's the same place where you edit your healthy and dry colors.
- The last detail you can edit is the render mode. Click it and change it from Grass to VertexLit.

Your ferns won't be unplanted anymore!
However, this rendering mode may not be ideal for your ferns.
When I tested this my ferns came out as blocky leaves with no transparency, while it works perfectly well for my rocks.
However you could treat your fern as a tree, which will keep it from moving and allow you to place them with a brush. It seemed to work fine for me.
The other option, of course, would be the slowest method : placing the individual ferns one-by-one onto the scene.