Converting Images into Doom Graphics

[Melemesh]

Hello, I've been confused about this for a very long time, and no matter how hard I try, I can't seem to find anything relating to this on the internet. Doom seems to use a specific file format for its textures, and while PNGs do work with ZDoom, they don't seem to work with vanilla, and since I want to make my map compatible with vanilla, I want the correct file formats. In SLADE, there is a button which supposedly can convert things to Doom graphics, like flats and such, but I tried using it, and nothing happens. I'm really confused about this and would really appreciate any help. If this is important, the texture I'm working with is a skybox.

[gwain]

its a bit weird you need at-least 2 images to do it 

https://drive.google.com/file/d/1eD1-a-1sJnCWioAxQ27o-cHMVBBr9Czk/view?usp=sharing

I used ctrl a in the video to select all if it wasn't clear

[Melemesh]

Huh that's pretty weird... Ok, thanks, I'll do that!

[Btyb88]

In Slade, when you try and convert, do you have it set to from "existing" to "doom"? It defaults to "existing" to "existing" which won't convert the png correctly

[Melemesh]

Ok so I finally got around to trying it out, and at first sight it seems to be working fine, but then there are these weird lines where the textures connect, and the yellow line on top of the texture. Any ideas on what might be causing this? Does it have anything to do with this being in Heretic?

[Borg]

Sky textures are a bit different. 256 x 240 is a normal dimension. You will have 4 vertical seams that need to tile properly. I have used 512 x 240 and 1024x240. The 512 will have 2 seams and the 1024 will have 1. The yellow line is a new one for me. Have never seen that one.

Doomkid has a tutorial for textures.

Maybe some clues in there.