Change F_SKY to display a different sky.

[Wadanny]

This seems like a very simple thing but somehow I can't seem to find a definitive simple description of how to do it (I've been through the forums with several searches). Basically I want to be able to change the sky which is displayed when the F_SKY texture is used in Doom Builder 2.

So for instance, in Doom 2 where there is one sky displayed for the levels set on earth (i.e. Factory, Suburbs) and then there is another displayed in the levels set in Hell (i.e. Nirvana).

I don't want to do anything fancy - just to change which sky texture is being displayed in the simplest way possible.

Any help appreciated!

[Gez]

It's a common question because the answer isn't very intuitive. Basically, the choice of sky texture is hardcoded in the engine and depends on the level; though advanced ports offer new features to control this behavior. Here's a recap of what is available as options to change the sky in a map:

Gez said:

The sky is made up of a texture: SKY1 in the first 11 maps, then SKY2 up to MAP20, and SKY3 for the remaining.

So you can:
1. Change the texture itself with a texture editor (will work in all cases)
2. Change the patches used by the sky texture (simplest, though it can break if people play with a Final Doom IWAD instead)
3. Change the association of texture to sky (requires some sort of MAPINFO, so not compatible with everything)
4. Use the MBF sky transfer special (requires compatible ports, but also allows to have several different skies in a single map)

[Kappes Buur]

n'jed by GEZ

All information needed is given in http://doomwiki.org/wiki/Sky .

Note:
Before you load the images into your pwad, make sure that the size of the textures is 320 x 200 and that they tile properly.
The image will be repeated for each major compass point, that is NESW.

SKY1, SKY2 and SKY3 are the texture names, but RSKY1, RSKY2, and RSKY3 are the patch names used for those textures.

Some ports support truecolor images, in which case png images are okay. For the rest, like DOOM.EXE, PrBOOM, the images
must be converted to the DOOM palette, which can give some ugly results.

Once you have read and understand how DOOM2 assigns the different sky images, have the 3 new sky images handy.
Open a new archive in Slade3.



Now, simply copy/paste, or drag/drop, the new images to UNSAVED (wad)*.
If not already named so, rename the imported images as RSKY1, RSKY2, RSKY3.



Save the archive as, for example mySKYS.wad.

Now, drag mySKYS.wad onto the icon for whichever port you are using.

With a bit more complicated method you can also make a non-repeating 1024 x 128 sky texture consisting of 4 256 x 128 images.



http://www.mediafire.com/watch/etf9xmmnumzkxtn/sky_2.mp4

[edit]
Of course, in DOOM2.WAD the sky images are 256 x 128.

[Blastfrog]

Skies are 256 wide, not 320. Also, safer to use 128 height, as 200 won't display consistently across all engines.

[Gez]

Sodaholic said:

Skies are 256 wide, not 320.

Skies are 1024 wide and will tile if the texture is a smaller power of two. Tiling will fail badly with 320 pixel wide. 256 is what id used, but in Final Doom you can find skies that are 512 and 1024 wide and it works just fine.

[andrewj]

Gez said:

in Final Doom you can find skies that are 512 and 1024 wide and it works just fine.

They work, but are a pain to create -- if you try to save a 1024x128 sky as a single patch texture if will fail because of 16-bit offset values in the patch format.