Start Actions on map beginning in UDMF

You need a script.

Script 1 OPEN

Floor_LowerByValue (tag,speed,height);

Something like this. Not at my computer.

you need to select the activation boxes below the actions. here's a full UDMF tutorial playlist by lazygamer. this one is about doors but the same goes for teleports, platforms(those are elevators in UDMF) and every other kind of action.

21 hours ago, Soupcan pyro said:

So I'm making a map that takes place underground in Ultimate Doom Builder. And I want to start the map with a elevator going down, but I don't know how to activate actions when starting the map.

https://youtu.be/2L76CxQ6T-Y

This, but in reverse. Right?

Video starts at 3:30.

The first example here shows an ENTER script:

https://zdoom.org/wiki/A_quick_beginner's_guide_to_ACS

and use maybe one of these:

https://zdoom.org/wiki/Elevator_MoveToFloor

https://zdoom.org/wiki/Elevator_LowerToNearest

https://zdoom.org/wiki/Generic_Lift

Reference:

https://zdoom.org/wiki/Script_types

The OPEN script type runs once when the level loads.

The ENTER script type runs once for each player when they enter the level.

The difference is subtle and mostly matters for multiplayer. If two players exist then the OPEN script runs once, while ENTER runs twice, once for each player.

Some ACS functions are only available in one or the other script type. For example: functions that modify players will not work in an OPEN script. Functions that affect sectors such as lowering the floor like you want should work in either script but belong in the OPEN script.