When I import my own tree in order for using as “Place Tree” feature, It rotates 90 degrees. Why?
When I use it as a regular object in my scene it’s ok.
Unity and Max use different coordinate systems, but Unity will automatically rotate your imported meshes so that Z is pointing up the same as in Max. However Unity uses Y as up in the Terrain Engine no matter what.
In Max you need to rotate your tree so that it is aligned in Y and then import that into Unity.