How add own custom sky?

I want take one picture from internet and make this on doom sky. How can I do?

I had taked one picture and made a size like RSKY1. After that import into SLADE and convert on doom. After testing I see, that these texture have negative look or they are cuted on half and looks ugly... I tried take two same picture. One of them I had mirrored horizontal and connect with other picture. The result is same... I need good explain how can I do.

I use only SLADE

The colors have to be within Doom's color pallete. IIRC, Slade has a feature where it converts a picture's colors to the closest alternative in the color pallete.

And don't forget to convert the picture to Doom format.

If admin read it, please move this thread on doom editing page :/

2 hours ago, Voros said:

The colors have to be within Doom's color pallete. IIRC, Slade has a feature where it converts a picture's colors to the closest alternative in the color pallete.

And don't forget to convert the picture to Doom format.

I did it, now I have another problem. I see, that this texture dont take on full picture. Its looks like cut on half size...

Why?Is a size wrong? I dont understand...

Here is a look what I wanted.

I'm trying to do the same thing.  My plan is to look into TNT.wad (evolution) to see how they did it with their e2 Sky.  Think that a sky for a non zdoom port has to be 128x256 hence the cutting off at what appears to be 256 pixels wide.  Try breaking the image down into 2 or more sections and defining them as they have in TNT.wad

I did it!!! Look at nice sky :)