how to rotate the landscape spline in whole.

hello,greetings.
I would like to rotate a landscape spline that I created.
but it doesn’t allow me to.
and I tried to find the spline on world outliner.but the spline wasn’t there.


I’m only able to rotate the spline points.I hope to rotate it like an object.

Thank you.

From within the landscape mode, this seems to be impossible.
However, the splines are accessible in the --selection mode–, you can select them there and rotate them through there.
It is far from perfect, the pivot tends to be off and splines can be combined in odd ways, but it is at least possible.