How do I get the sky texture to work in-game?

[DoomMan007]

UPDATE to this question, so it looks more like they made a skybox?  In the Chex Quest 3 wad, E2M1, there is the normal sector you run around in, and another sector, which looks like a copy, but of only a few main rooms.  They did use F_SKY1 as the ceiling texture in the other sectors, but in the sectors you run around in, the ceiling texture is that CJFCOMM5 texture.  I used F_SKY1 for my texture, but it brought up a sky filled with mountains.  I wanted to hopefully get the city skyline to show up, but again, I just don't know how.  It's been so long since I've map edited, so any help on this is really appreciated.

 

For example, if you are making a map in Doom, all you have to do is, place the f_sky texture as a ceiling texture, and you'll have a room that appears to be outside.  In Doom 2, if you want to use that orange looking sky texture, it's not even in the list of available textures.

 

In Chex Quest 3, in E2M1, you begin outside.  So I am just starting to make a new Chex map, and I've run into a roadblock.  In the Chex Quest 3 wad, in Doom Builder 2, the ceiling texture used to make it appear you are outside is, CJFCOMM5 <--- (yes, but I think they used a skybox).  In the map I am making, I have selected this ceiling texture.  Now, I was told that Chex Quest 3 is Doom (hexen in zdoom) format, when you open it in Doom Builder.  I have selected this option for making my map, just to try to stay as close as possible to the original format.  Problem: The ceiling texture is not showing up as being an outside texture.  Instead, it's just a flat ceiling.

 

Question: How do I get the ceiling texture to actually show up as a sky like it does in the original Chex Quest 3 game?

Edited September 7, 2018 by DoomMan007
I don't understand how the original developer did this.

[how to delete account]

Depends on format of your map.
2 most popular formats are boom and udmf, both of them have their own way to do such effect
For udmf its as easy as defining sky2 in your mapinfo file
Like this:
map map01 "levl"
{
    levelnum = 1
    next = "map02"
    sky1 = "(here goes your sky)", 0
    sky2 = "(here goes your another sky)",0
    cluster = 1
} 
And then selecting all of the sector you want your second sky to appear, and adding a sector special "200 SKY2(mapinfo)" to them.

For Boom it can be done with drawing a line, giving it a "Sky Transfer" action, tagging it, choosing the texture for your sky and pasting it on the upper side of your line, and then assigning sector tags to be the same as your sky transfer lines tag.  

Heres some screenies, just in case

For boom






For udmf

 






Good luck with mapping!