Questions about Zombie behaviors

[Apocalyptical Survivor]

I build a decent horde base that provides ramps for the zombies to ascend, and funnels them into a narrow bridge to my elevated bunker, allowing me a good opportunity to shoot them as they approach. When they inevitably fall off the narrow bridge, they land on a walled slab of concrete from which they usually can't escape my guns and molotovs. My bunker sits atop mountains of concrete and is multiple layers thick, so I'm well protected and able to just shoot forward safely in my bunker. The bridge is pretty straightforward, made of steel with steel barriers for them cross to slow them down on their way towards me. Works well.

 

But I've noticed some odd behaviors and I'm trying to understand how zombie behave. Some of them, when climbing the ramp, stop and try to destroy it, which seems very counter productive since it's their only way to me up in my cage. Als0, they don't always funnel correctly and sometimes just stop along the way and try to destroy walls that will get them nowhere. Are they really just randomly motivated or are there some reliable rules of engagement in directing them toward a specific objective?

 

What factors influence zombie behavior. I appreciate any insights or suggestions, thanks!

[zztong]

I've noticed similar. My guess is destroying the ramp eventually cuts them off from your intended path. Once your intended path fails, the next best path is to knock down the tower upon which you stand. So, while most run through your abattior, the quirks give you the fun of having something else to plan for.

[Crater Creator]

They have a 'destroy area' mode which they're primarily supposed to use when they can't deduce a path to you. This is handy for example if you're on a raised platform with no way up: you must have a pillar somewhere supporting that platform, which is what they'll theoretically attack. But they don't think through the consequences of destroying blocks; they just start destroying.

 

I understand more randomness has been introduced for the sake of making them feel more natural, and less like every zombie makes the same beeline as if they're controlled by a hive mind (they kind of are). In cases where they do have a path, I don't know the particulars of when they may start attacking instead of taking the path.

Edited July 11, 2022 by Crater Creator (see edit history)

[theFlu]

16 hours ago, Apocalyptical Survivor said:

Are they really just randomly motivated or are there some reliable rules of engagement in directing them toward a specific objective?

They're somewhat random, but destroyArea should mainly be triggered when they either

1) can't find a path to you or

2) fail at following a path (fall down)

 

If it's common in your base, then you likely have a setup where they can't always find a path.

 

I don't know the specifics, but the zeds do see each other in their pathing as well. For example, if there's a dog standing next to a 2-high wall, zeds can use the dog as a step up, and climb the wall from there. Same goes for walking across moats, if you have a moat (narrow and shallow) that has zeds running at the bottom, others can cross the moat by walking on them.

 

I think - this part is a whole less obvious, but might be applicable - that the zeds also see each other as some kind of "horizontal block" as well. It's not clear cut what they do with that, but it seems that sometimes a "jumping obstacle" can prevent others from following. Basically imagine a straight one-wide path with an extra block on it for the zeds to jump on; with a zed standing on the obstacle, the ones behind don't see it as a path anymore.

 

The pathing updates are not instant, so the ones behind won't all react to the blocked path, just when it happens to be blocked while they update their pathing. This would explain it being somewhat rare, but constant.

 

All of that is highly speculative, being derived mostly from intuitive base building, with some limited testing involved... but it might help

 

To test, try thinking if the path to you is easily blocked by a zed, and try to give the zeds more options on the same path - if you're using a jumping obstacle as I described, give them a walk-around at that point, with a piece of sturdy wall blocking the path at the obstacle. That might lure them in on your intended path even while it is temporarily blocked.

[8_Hussars]

I thought I just recently read here a hint at a 40 block limit for zombie pathing, otherwise rage mode or they forget where you are.

Which I took to mean if they cannot path to the player within 40 blocks they go into "rage mode" (destroyArea) and then recalculate pathing again. 

Edited July 11, 2022 by 8_Hussars (see edit history)

[Roland]

The length of the path that zombies can sense is variable. Some see paths to you from a great distance and others don't. A Short Pather is more likely to go into destroy area mode since they can't detect a pathway to you. In A17 all zombies had the ability to see very long paths as well as many alternates and could even break obstacles specifically to make a path. That has been cooled quite a bit and while there are plenty that can find their way to you there will be some Medium Pathers and Short Pathers that will struggle or completely fail and just go into destroy mode. On horde night it is quite apparent which ones are dumb but that isn't the only time. When exploring POIs you will find that some zombies can navigate anything and wind their way through several rooms and across catwalks and relentlessly stalk you while others will be right in front of you but turn to a window or wall and start banging on it because they can't see the path to you, bless their hearts.

 

Damaging a zombie that is in destroy area mode is supposed to kick them out of it and put them back to trying to reach you.

 

I, personally, really miss the Terminator like zombies of A17 that never stopped coming for you and knew (even better than you did sometimes) what routes to take to get to your brains. But, admittedly, it wasn't very zombie-like behavior even if it was frantically horrifying fun at times.

[Kyonshi]

I build ramps/staircases access to my horde base and I've observed that some of them destroy the base of it when zombies ahead of them are so packed up on the first step of the staircase. It prevents the ones below to climb of it for a certain amount of time, triggering their destructive behavior since they consider the access unreachable. There's so many zombies in the constant flow of a 64-zombies hordes that some of them remains trapped at on ground level for so long that they'll just start hitting what's in front of them.

[Syphon583]

Unfortunately without seeing what you're dealing with (preferably in video format) it's just a guessing game as to what's causing the issue. As good as the zombie AI is in the game at knowing structural integrity, their pathing mechanics sometimes cause a bit of head scratching. Trying to "control" a zombie's path is almost a mini game in itself and it really just comes down to trial and error. What you're describing should work as intended. But there are a lot of other factors to consider like block strength, integrity, placement, surrounding obstacles, height, wind speed, temperature, celestial alignment, etc. (ok, those last few might not matter) but again, it's really best to just see what works what doesn't, and make adjustments from there. As far as I understand the AI pathing, a zombie's first goal is to get to the same level as you, then after they reach that level, find the path of least resistance. So any obstacles you put on that bridge might complicate that.

 

If it were me, I would avoid making any sort of additional obstacles on that bridge. If they're climbing over other blocks, that makes it harder to get clean headshots (it also could cause the AI into thinking there is a better path to you than the one you want them to go). If you want to slow them down, I would recommend replacing your ramps with just regular old cube blocks. That way they're forced to jump up to the next level. If possible, make those paths up at least 2 wide so if they somehow manage to destroy one of the "steps", there is still an open path to you. Also if possible, make more than one "staircase", like one on either side. Slowing them down on the way up gives you an opportunity to toss mollies (assuming that path is close enough to you) so you might not need that pit or whatever it is at the bottom. I always prefered giving the zombies a loop so in case they do fall, they might decide to come back up the steps instead of going into destroy everything mode (if the fall is more than 5-6 blocks high, I think the chance of them going into destroy everything is higher)

[Crater Creator]

12 hours ago, Kyonshi said:

I build ramps/staircases access to my horde base and I've observed that some of them destroy the base of it when zombies ahead of them are so packed up on the first step of the staircase. It prevents the ones below to climb of it for a certain amount of time, triggering their destructive behavior since they consider the access unreachable. There's so many zombies in the constant flow of a 64-zombies hordes that some of them remains trapped at on ground level for so long that they'll just start hitting what's in front of them.

 

I know you're probably sharing this just as an example of how they behave, but I wanted to mention... I've used similar designs, but I often build in redundancy. Instead of one staircase/ramp leading up to the raised platform that takes zombies towards me, I'll build a staircase/ramp on three sides of a pillar (technically I use a coarse 'staircase' of full blocks, because jumping is slower). I don't play with 64 zombies, but the number that beat on my structural supports stays minimal.

[doughphunghus]

On 7/12/2022 at 12:38 AM, Roland said:

I, personally, really miss the Terminator like zombies of A17 that never stopped coming for you and knew (even better than you did sometimes) what routes to take to get to your brains. But, admittedly, it wasn't very zombie-like behavior even if it was frantically horrifying fun at times.

If the bandits can do this, that will be a nice touch. basically "they're human so they can navigate right to you". especially if there are wandering bandit hordes or similar so they all come up/into buildings as a gang.  it would also be kinda neat if they had helmet/gun/flashlights so you could see them searching and when they got right in front of you the lights kinda blinded you (like a brief debuff) or were hard to look at if in the dark (like real flashlights do when shined in your face) if you weren't wearing the sunglasses.  I think they should be able to put down the wooden ladders/stairs/lattice in front of themselves to scale walls to get to you, only breaking doors/blocks when you're sealed in. then those ladders would remain for zeds to get to you unless you broke them down.

Edited July 17, 2022 by doughphunghus (see edit history)

[Roland]

39 minutes ago, doughphunghus said:

If the bandits can do this, that will be a nice touch. basically "they're human so they can navigate right to you". especially if there are wandering bandit hordes or similar so they all come up/into buildings as a gang.  it would also be kinda neat if they had helmet/gun/flashlights so you could see them searching and when they got right in front of you the lights kinda blinded you (like a brief debuff) or were hard to look at if in the dark (like real flashlights do when shined in your face) if you weren't wearing the sunglasses.  I think they should be able to put down the wooden ladders/stairs/lattice in front of themselves to scale walls to get to you, only breaking doors/blocks when you're sealed in. then those ladders would remain for zeds to get to you unless you broke them down.

Devious!  I love it!!