How can I achieve this? [wall lowers once a certain enemy is dead]

[Subatomic]

I'm using Doom Builder to create a new map for Doom 2. There's an idea I had that I'd like to implement, but I'm unsure of how to do so. Basically, I want to trigger a section of wall that will lower to reveal a yellow key. The part where I'm unsure at is that I want the wall only to be lowered once a certain enemy (Cyberdemon most likely) is defeated. As long as he's alive, the wall remains raised. Once you kill him, the wall lowers and you obtain the yellow key.

Is this possible?

[Remmirath]

Well, it cannot be done with vanilla doom unless you're going to use a mancubus, and it must be on MAP07.
Otherwise it can be done with ZDoom ACS scripting with this basical function

script 1 (OPEN)
{
while(thingcount(T_CYBERDEMON,monstertid) > 0)
delay(70);
Floor_LowerToNearest(tag,speed)
}

[Subatomic]

Ah, bummer. I don't know anything about ZDoom (I use Doomsday/jDoom) or how to use its scripting features. The section of wall was going to be at the far end opposite of where the player enters at, so I might just "disguise" it with textures that match the surrounding walls. Once the Cyberdemon is dead, the player can freely search the room then.

Thanks for the quick response though, I appreciate it.

[esselfortium]

A common way for this to be imitated, while it's not quite what you have in mind, is to create two or more switches, all of which must be hit to make the key accessible (by opening however many doors or bars are in front of the key), which are placed in such a way that it's difficult to push all of them while dodging fire. This way, the player won't have to kill the monster to access the key, but they will have to at least fight it and dodge its fire for long enough to push two or three switches scattered around the arena.

Alternately, for Boom, (caution: advanced techniques ahead) you could give the Cyberdemon the A_KeenDeath codepointer in one of its death frames using DeHackEd, and place a voodoo doll (an extra player 1 start, which appears as a Doomguy that the player doesn't have control over) in a dummy sector somewhere outside the map, with a scrolling floor beneath it...then put a small door in front of it with tag 666 (or was it 667? I forget which tag A_KeenDeath opens), so that it will open when all Cyberdemons in the map have been killed, and put a walk (W1 or WR) trigger on the other side of that door that lowers the wall you want. This wouldn't have the intended effect if there were other Cyberdemons in the same map, though.

For Doomsday, I think you might be able to do something with XG scripting and/or DED files, but to be honest I know next to nothing about them. :X

[Grazza]

esselfortium said:

Alternately, for Boom, ...

Or indeed vanilla/limit-extending. This isn't a Boom feature. (Not intended as a nitpick, but as a useful clarification since not all ports have complete support for Boom features.)

esselfortium said:

tag 666 (or was it 667? I forget which tag A_KeenDeath opens)

666

If you wanted to have other cyberdemons in the map, then I suppose you could replace a monster you are not using (WolfSS?) with a "special" cyberdemon, that has the Keen codepointer aassigned to it. Though it would then lack the "Boss" features of immunity to splash damage and roaring loud.

[esselfortium]

Grazza said:

Or indeed vanilla/limit-extending. This isn't a Boom feature. (Not intended as a nitpick, but as a useful clarification since not all ports have complete support for Boom features.)

Yeah, I thought of the fact that some aspects of that setup could be done in vanilla, but he specifically said he wanted a wall to lower, which needs the conveyor belt.

[swordgrunt]

Grazza said:

Though it would then lack the "Boss" features of immunity to splash damage and roaring loud.

Would those abilities be acquired if the monster ID# was changed to the Cyberdemon's? I think that needs to be done to change the attack type (from the nazi's hitscan to the cyberdemon's rockets) in DeHackEd as well; otherwise it would be a nazi with the sprites and sounds of the Cyberdemon without altered behavior.

[gggmork]

I asked this here myself awhile ago, and an easy, less advanced, way to do it is make a doombuilder 'zdoom doom in hexen format'. Then simply select the cyber and give it an action tag (action happens when it dies). Disadvantage is you have to use zdoom. (remember to enter a speed and such for the action as hexen actions are a bit different).

An alternate rough equivalent is have a really tall sector constantly lower then try to time it so its all the way down approximately when the cyber should be dead anyway (or similarly have a dummy player1 start outside the map on a scrolling floor. A linedef near the cyber triggers a block to go down and the dummy scrolls down a long corridor similarly timed.