Use custom skies (PrBoom)

If I want to use another sky texture than the usual sky texture in the episode, how can I do it?

e.g. as it happens in Claustrophobia 1024/ 1024 2.

Lindef type 271 - MBF Sky Transfer

Thanks!

272 is also a sky transfer type. One reverses the texture, as DOOM normally does, and the other does not. Which is which, I don't remember.

Why does Doom reverse its sky textures, anyway? Is it a bug, or bizarre intentional behavior that only Carmack or someone else at ID could ever pretend to understand?

esselfortium said:

Why does Doom reverse its sky textures, anyway? Is it a bug, or bizarre intentional behavior that only Carmack or someone else at ID could ever pretend to understand?

So very much this. It makes no sense.

esselfortium said:

Why does Doom reverse its sky textures, anyway? Is it a bug, or bizarre intentional behavior that only Carmack or someone else at ID could ever pretend to understand?

I'd guess that he took a normal geometry class, where angles are measured counterclockwise.

Sodaholic said:

It makes no sense.

Makes perfect sense to me.

tempun said:

Makes perfect sense to me.

It makes no sense that anybody would think that it makes sense. Seriously, where's the logic in rendering the sky backwards??

tempun said:

I'd guess that he took a normal geometry class, where angles are measured counterclockwise.

This was always my assumption as well. The 0 column of the image is rendered to the north(?), and every subsequent column is rendered counterclockwise from that. I haven't actually bothered to check into the sky code myself, though, so I'm not sure if that's all it is.

Quasar said:

272 is also a sky transfer type. One reverses the texture, as DOOM normally does, and the other does not. Which is which, I don't remember.

272 reverses the texture. I only recently noticed the reversal in Chocolate Doom when adding text to a sky texture.

@Sodaholic - DON'T PANIC! The sky isn't falling, that's just the way it's rendered.

And how to use this action?

I made a quick wad to demonstrate how to use this feature:

http://www.mediafire.com/?351oysmscn4fg6a

What you need to do is make an inaccessible dummy sector off the edge of the map and give all lines type 271. Make sure you set their front side, upper texture to your desired sky.

For ease, you can use tag 0 to apply it to all the sky sectors in your map, but you'll have to add more type 271 lines with appropriate tags if you need to make a moving sector with a sky texture.

Assign a tag number to the sector or sectors you want to apply the Sky Transfer to, then select a linedef (in one of the sectors or a dummy) and add to it -

• The sky you want - as an upper texture
• Linedef type 271 or 271
• The sector's tag number

Stuff like outdoor teleport sectors which already have tag numbers will need to be given their own Sky Transfers, so you don't wind up with holes in the sky. The demo map linked below (which I seem to keep recycling) might explain things better than the text above.

http://www.mediafire.com/?59pr17shh2g7tdg

Ninja edit - beaten to the post by skillsaw.

Thank you, skillsaw! I didn't expect that you will help me! :D

Katamori said:

Thank you, skillsaw! I didn't expect that you will help me! :D

No problem, I'm always happy to help!

Something that still trips me up (because I'm an idiot) that might be worth mentioning is that you'll want to make sure all of your sky texture alignments in your dummy sector are aligned to 0 (both x and y). If your only using one tag, this isn't a problem. But more than like you'll have to split up your sky transfer line to accommodate extra tagged sectors that use the F_SKY1 flat. If you don't set the alignment to 0,0 for those extra transfers, this happens :P (for some reason I keep forgetting this, even after being told how it works on numerous occasions)