How the hell do the stair builder line actions work???

[CNDLWYX]

I just can't seem to wrap my head around them and it's bugging me cause I've been trying to use one but it won't cooperate.

[Stabbey]

The stairbuilder operates on a few conditions.

The first is that you tag only the starting sector (or sectors for multiple flights) of stairs. The second is that all the stairs must have the same floor texture as the initial sector; any sector with a different floor texture gets skipped for the stairs.

 

Once the action is triggered, all lines facing into the sector which have the same texture on their sector will begin to raise to 8 (or 16) above the height of the previous stair. Each of THOSE sectors will then check for lines facing in from sectors with the same floor texture, and the process will repeat until either the stairs reach a sector which has no lines facing in, or no adjacent sectors with a different floor texture.

Edited April 5 by Stabbey
third condition... doesn't exist

[Caffeine]

Worth adding that Stabbey's explanation is for vanilla Doom: if you are using Boom or UDMF there are other methods.

 

Boom has generalized stairs that allow you to control them more precisely. For example: generalizing up or down, 8 or 16 units, speed, whether or not the stairs reset to their initial state, and whether individual steps need to have the same floor flat. https://zdoom.org/wiki/Generic_Stairs. Other than that, they follow the same building behavior as the OG Doom type.

 

UDMF supports Boom's method, but also has action special 27 (among others) that offer even greater control. Sectors in UDMF can have several effect types, including 26 and 27 which are required for the UDMF stairs action specials. The sector tag indicates which is the first step: from there, the engine looks for adjacent sectors that have alternating effect types of 26 and 27 but still going from "line front" to "line back" to find them. This way, sectors can have wildly different properties although I believe the floor height must still be the same. Anyway, this is nice because you can have a ton of sectors that might otherwise be triggered by the stair builder, but due to the constraint of those new effect types, stay put. In other words, it is more difficult to screw up although it does take more work to set up.

[Gez]

If using ZDoom UDMF, you may find this example map over there useful.

[zokum]

The steps do not need to have the same height as the starting sector. The four raising stairs switches on Doom 2 map 21 is a good example of how this can be done.

[Stabbey]

24 minutes ago, zokum said:

The steps do not need to have the same height as the starting sector. The four raising stairs switches on Doom 2 map 21 is a good example of how this can be done.

 

Okay, I didn't have that one in initially, but after someone suggested it, I thought it might be the case and I didn't feel like making a test map to try it.

[Chameeleoh]

Check out ChubsDoomer tutorials! This guy is super thorough.

 

https://youtu.be/rFPPKNFum2w?si=L2n2tcrlJV9mQvrf