Alright. So I made a terrain, and planted trees on it. I planted a few Palms and some Thin Trees, however, my problem is happening without the thin trees as well. Basicly, when I walk close to the trees they move from a few inches in the air to down in the ground a bit. does anyone know why? and if I can stop it?
The reason for this is simple, actually.
The terrain uses several Texture2D maps for its various properties.
A height map for topography, splat map for terrain texturing and a tree map for, well, trees.
The reason why you get these floating trees is because you have a tree painted on the tree map in such an area that does not quite sync up with the height map. You will most likely see this occur on a slope.
karl is correct in placing manual trees in places, however since these trees aren't terrain trees you lose the ability to billboard and such automatically through the terrain object.
These trees are painted onto the terrain and attached at their registration point/pivot, the bottom of the mesh. A potential fix could be to build custom trees, extend the trunk a little ways below its pivot which should give you a more attached look in those tricky areas.
[EDIT]
I took the Alder.fbx model into Maya and extending the trunk down a bit, past its pivot on the Y-axis. Upon taking the model back into Unity and correcting some textures and stuff I see that the terrain indeed attaches the tree at it's pivot, allowing some of the trunk to sit below the terrain. This, however, did not do the same for the billboards and therefore some floating may still occur in that case. My advice to you is to simply play with your settings in which trees fade to/from billboards and find a happy medium there.
Hope that helps,
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Is this using the demo project?
This is a new scene under the demo project, yes. Eventually I would like to remove the scene from the demo project, however, I have been worried about breaking the scene so have not done it. Thank you for you answer Karl, I suppose iwill have to plant them all manually.
You can avoid this by manually placing trees, but I'd like to know a way to avoid this while using the mass tree placement terrain tool too