Amon, you can flip a terrain, for making the roof of a cave. You would create one terrain for the floor, and another for the ceiling, and build your cave out of that.
For rendering terrain in the editor, I will use vertex alpha, since it is the simplest. For rendering in the engine, I will either use vertex alpha or a texture mask for non-shader cards, and a shader when it is available.
For rendering terrain in the editor, I will use vertex alpha, since it is the simplest. For rendering in the engine, I will either use vertex alpha or a texture mask for non-shader cards, and a shader when it is available.