Seamless skies from ceiling to walls?

I was wondering what the trick was to creating skies on walls that blend with ceiling skies... There's a part on my map where there's a low wall that's supposed to look like it separates the map from the city sky texture, but the area behind it doesn't blend with the actual sky and just looks like a big tapestry. The perspective doesn't allow tricks like extending the sector behind it really far for it to just make the ceiling visible.

I've seen this trick done before in the Momento Mori series, and I recall that it had something to do with creating a dummy sector that extends past the linedef where you want the actual sky texture to be. I don't remember the details, though.

Thanks for any ideas :/

Adjacent to the room with your F_SKY ceiling (A), place a sector (B) with the same floor height and with a lowered ceiling and F_SKY for ceiling texture. This will give you all-around sky. For something better, do this: sector A floor/ceiilng height = 0/128, ceiling texture = F_SKY; sector B floor/ceiilng height = 32/32, ceiling texture = F_SKY, fill lower texture of border but leave upper texture empty. This will give you a all-around sky but with a small wall blocking the horizon.

Of course, as with all simple stuff, you could just load an original map in your editor to see how they have done it there. That's the best way to learn basic stuff.

Good luck!