Get Altitude in Texture
Provides the "Altitude in Texture" of the current Render State. The Render State is affected by any shaders which were called before this function is called, among other things. Get Altitude in Texture provides the signed difference between Get Position in Texture and Get Position in Geometry in the direction of Get Normal in Geometry. For a planet this basically means the altitude of the current texture coordinates.
The input connection is not used by this node (consistent with all Get nodes).