COD5 "Nazi Zombies" Barricade system?

I’ve got a simple, sort-of-working system for a “Nazi Zombies” type map, pretty much, you enter a trigger, and three frozen boards appear one by one in the way of the door. But, you can keep doing it, and you have like 20 boards all inside of eachother, which fucks up the purpose of the map.
What I want to know is:

  1. How do I make a point_template only able to have one spawn at a time? (Meaning, it won’t spawn if it already has an existing spawn, ex. I have two lower boards, but not the top one, so I try to rebuild it, and it only rebuilds the top one instead of making two more boards inside the other ones.
  2. How do I make a trigger where, once entered, it will begin doing actions, but once you exit, will stop? I don’t like using simple “OnTrigger”, because you can run into it and run away and the actions will still be going on. I also tried using “OnTouching” but that didn’t even work at all.
  3. Why won’t my zombies (npc_zombie) attempt to break the boards? They usually attempt to hit physics props that are in their way, but this time they aren’t. Is it because they know the props have motion disabled? What can I do to make the prop fixed in a certain spot, but considered by zombies to be throwable?

1, math_counters, timers
2, have the triggers disable and enable new ones.
3, add a npc_target?
or an ai_relationship (i have no idea if that would work)

I dunno about your current issue but here’s another workaround:

Start off boards placed somewhere. Assuming you can pick them up (Depends on the game) you can put a trigger once/multiple with trigger_teleport sharing the same place. Add a filter for the trigger_teleport to only teleport boards, and then use an info_target as the destination. This way you can add rotation and it looks cool.

Parent a npc_bullseye to the boards before you teleport them. Start it off disabled, and when they are teleported in place infront of the door, enable the bullseye. This will make the zombies want to break them.

Yeah my way was pretty sketchy… use neds

I tried your way, Ned, and it works, but the zombie doesn’t seem to want to attack the bullseye. He just walks around like there’s something in the way of hurting me. I have it parented to a func_physbox named ‘board’, and it’s pretty much inside it, and the bullseye set to filter things named “zombie” (I have a npc_maker that spawns npc_zombie’s called ‘zombie’), and I have it so once the board is set in place the bullseye is woken.
I think it’s either that I should use a prop for the board instead of a func_physbox, or that I need to use something else other then Sleep/Wake to make the bullseye an available target.

[editline]10:38PM[/editline]

I just tried putting an ai_relationship in and setting them to hate eachother (lol boards hating zombies just as much as zombies hate boards) and the zombie shuffles around the board, stops in front of it sometimes and faces it like he’s going to attack it, then, as if he can’t, goes around the other side of it and it repeats.

[editline]11:50PM[/editline]

And, I see a problem with that. How am I supposed to get several “settable” boards?

Somebody help, please

Does nobody know?