[转] Edit Terrain foliage/texture at runtime
http://answers.unity3d.com/questions/13854/edit-terrain-foliagetexture-at-runtime.html%3Bjsessionid=56253384979EAB293764FD170409DB79?sort=oldest
http://answers.unity3d.com/questions/13854/edit-terrain-foliagetexture-at-runtime.html%3Bjsessionid=56253384979EAB293764FD170409DB79?sort=oldest