Sky Transfers

[xaekin]

There's a couple boom linedef specials for changing the sky used in a map, and you can use them to set most textures to be the sky if you choose.

 

Is there a way to change the sky texture mid-level? As in, is it possible for a boom format map (say, complevel 11) to have an area that starts with sky1, and then after hitting a switch, turn the same area to sky2?

 

I can think of ways to fake it with silent teleports, but it would help sell the progression I intend to create.

[Gez]

You need to change the texture on the line doing the sky transfer. AFAIK, there's no effect for that in Boom; you'd have to use ACS or alternatively perhaps FraggleScript. There are switches that alternate between one texture and the other, but the sky transfer line will already have a sky transfer effect, obviously, so you can't give it an S1 effect.

 

Something you could try is to define a pair of very tall sky textures (you may need to go 512px tall to be safe). Put both skies one atop the other, so you end up with a sky texture that's like 1024-px tall. Then use one of the Boom line texture scroll effects to make the texture scroll 512 units up exactly once.

 

With software rendering it should work, even ZDoom with freelook will only display about 512 vertical texels' worth of sky. GL renderers may not work as intended, though.

[xaekin]

On 4/8/2020 at 5:32 PM, Gez said:

You need to change the texture on the line doing the sky transfer. AFAIK, there's no effect for that in Boom; you'd have to use ACS or alternatively perhaps FraggleScript. There are switches that alternate between one texture and the other, but the sky transfer line will already have a sky transfer effect, obviously, so you can't give it an S1 effect.

 

Something you could try is to define a pair of very tall sky textures (you may need to go 512px tall to be safe). Put both skies one atop the other, so you end up with a sky texture that's like 1024-px tall. Then use one of the Boom line texture scroll effects to make the texture scroll 512 units up exactly once.

 

With software rendering it should work, even ZDoom with freelook will only display about 512 vertical texels' worth of sky. GL renderers may not work as intended, though.

 

While constructing the sky texture is easy enough, there doesn't seem to be a way to actually scroll the sky, since the scroll texture boom action doesn't apply to tagged lines, only the linedef that has the action. So yeah, I couldn't do it without ACS or similar. Since I'm not terribly keen on trying to learn fragglescript for this project, and faking the transition with duplicate locations and silent teleports is definitely doable. Thanks for the help, Gez