When using the ARCamera with the Cardboard the camera view is narrower than the usual Cardboard barrel distortion viewport rendering. This is likely due to the aspect ratio of the Galaxy S6 camera I'm using. The issue is that the Unity Terrain is not clipped by the narrower Vuforia camera masks. You can see that in the attached photo. The water is clipped just fine but the Terrain is not. The Terrain is filling out the whole Cardboard viewport.
How can I achieve that the Unity Terrain is masked/clipped by the narrower video overlay?