Making it draw 3rd person view
An early screenshot from making it draw 3rd person view. Here, the camera is in the 3rd person view position, but it's still using 1st person frustum culling. This allows you to "see" under the ground. It isn't until you see a shot like this that you're reminded that outside the rendered scene in a game there's nothing there. If you've ever fallen through the cracks in a level in Oblivion, you know what i mean.
Needless to say, 3rd person now sets the culling frustum correctly, and you can no longer see under the ground.