Last time I saw it was in 1 of the wilderness forts, the trench around a couple of tents and tower with a bunker. The loot room has bulletproof glass walls so it was very clear to see. I don't know which is the intended side since either path was open. I came through the hydroponics room, the other side is the kitchen.
I tend to follow the path since I feel like I am missing out when I don't. Sure it's fun when the zed just stands there oblivious and waits for me to walk right up and smack it when I come from the wrong side but it feels broken. Granted even obvious trap is easy when you just plop down 2 QL6 turrets in a chokepoint and watch the fun.
When you get within 4 blocks of a zombie volume the game will select sleepers and place them. You might see them appear if you're in the right place, but usually a designer tries to hide them behind something so that from a distance you don't see them appear. That's just normal zombie volume behavior.
A normal volume can be an Attack volume, which will wake the zombies upon entry, though the zombies may not know where you are. If it's a relatively small volume you might be so close they can't help but see you. If you're shooting a gun they will quickly figure it out. A stealth player can break contact, re-engage stealth, and lose them.
With a Min Script, there's some kind of triggering event, like a door being opened, a button being pressed, or the player entering a trigger volume. I'm not entirely sure of all the blocks that can trigger events as I'm relatively new to using them. The Min Script can do a variety of things, including triggering other events, spawning zombies, pausing, pausing until there are only a certain number of zombies left, and playing sounds. I'll bet at some point it will have some integration with all the bizarre Twitch things.
It might be impossible to tell an attack volume from a trigger volume apart if it just involves zombies, unless you get the zombies down to some number and then all of a sudden there are more zombies or you know you did something like open a door, press a button, etc. A trigger volume that just activates some sleeper volumes would play out like an attack volume.
I think. I might be missing something in there.
The Min Scripts allow those POIs to do some interesting things, like make barrels explode. You could have a fight start with zombies to the front and then 10 seconds later activate zombies behind. I've not checked, but perhaps even opening the final loot chest could be a trigger.
If you've got my modlet installed, the Tier 5 Ranch has a Min Script that tries to mimic a tripwire, though sadly it doesn't look like a wire. As the script plays out it beeps like a Placed Charge for a few seconds giving you a chance to say "what's that" (or flee if you have your wits about you) before a block explodes. That's pretty deadly, specially if you flee towards the exploding block. I worry about that as even a player with the Perk to avoid mines can set that one off. Somebody might not think it was fair.