I am making a fast-paced space shooter. I have several levels to each area: the entity layer where I put everything that the player needs to interact with (usually shooting it or running in to it), an area below that which is where there are floating platforms and misc. effects and things like rocket turrets, etc.

What I need now is to put in a spiffy background, it needs to go below the platform area; the game is viewed at a 45 degree angle downwards (sort of isometric but from behind the player) so the background would need to extend outward in front of the player.

1. Cube maps are a waste of time because most of it isn't being viewed.

2. I am thinking about using a flat model plane and sync it up to the player's location. In order to avoid it looking like a flat plane with a pic on it, I would have to make it HUGE and far below the player and have it face the camera without allowing it to cut into the geometry and entities near the top of the screen.

I was mainly wondering if there was another way that someone might suggest.