Setting to enable exporting trees, grass and detail meshes from the Unity terrain data.
Trees are exported under Trees game object, which is the child of the generated terrain game object.
If there are chunks, each chunk will have Trees game object as the parent.
Exported trees are the original prefab instances, and their transforms are read from the terrain data.
Details are exported under Details game object, which is the child of the generated terrain game object.
If there are chunks, each chunk will have Details game object as the parent.
Exported details are mesh prototypes for detail mesh, or quad meshes for grass.
Exported grass has a Billboard grass rendering feature but doesn't have color variation, distance fading and wind features yet.