With the sky.scene flag, the texture size can "be bigger than the texture size limit of the 3D card." I understand that to mean that even on old voodoo cards with a 256x256 limit, I could still use a gigantic sky texture.

Does this still apply to 6-sided sky cubes? Generally, how badly is bitmap size going to impact performance? For instance, is a 1024x6144 map as insane as it sounds to me or are these sky images a lot less expensive somehow? (I'm trying to keep my texture usage very low).

Edit: Well, I tried the 1024x6144 map and my Quadro4 couldn't even generate it--not to mention how unbelievably huge the bitmap was. But that makes me wonder . . . could an old voodoo card could even handle a 256x1536 panorama?

Edit2: With this panorma I could actually just re-use the same bitmap for the North, South, East and West. Then a 2nd for both the top and bottom of the cube. Is there a way to feed just two separate bitmaps into a skycube? Or do you have to use all six of them stapled together? Maybe I can use a normal sky cylinder for the walls and a separate sky dome for the up--then reverse it for the down?

(This level takes on walkways in the middle of an infinitely tall machine room--it's not really a normal level).