TerrainEngine current Features.
Multi-threading, LOD, Mesh Batching, Grass , Climbing Plants/Grass, Realtime fluids, Procedural world ( with editor tools/gui ), Colliders, PathFinding ( Ground/Aquatic/Flying path), Fully interactive world, remove add plants, manage all events and play any effects (like falling leaves or snow when tree fall).
Project : http://forum.unity3d.com/threads/1745...