What can cause an enemy not to teleport?

I’m having a glitch at the end of Map 18: Mill on TNT Evilution. In the cyberdemon area, I believe there is a zombie that didn’t teleport in for some reason. I am missing 1 kill, and the whole map is clear except for that I can hear a lower tier enemy grunting and groaning whenever I walk near the chaingunner/hell knight teleporter, which is right next to a wall with a hole (like an inaccessible room that they are stored in before teleporting). What might cause him not to teleport? I’m gonna do the map again but I don’t want the same thing to happen because it’s a longer map and this is at the very end before the exit! Thank you! 

1 hour ago, LucidLocomotive said:

I’m having a glitch at the end of Map 18: Mill on TNT Evilution. In the cyberdemon area, I believe there is a zombie that didn’t teleport in for some reason. I am missing 1 kill, and the whole map is clear except for that I can hear a lower tier enemy grunting and groaning whenever I walk near the chaingunner/hell knight teleporter, which is right next to a wall with a hole (like an inaccessible room that they are stored in before teleporting). What might cause him not to teleport? I’m gonna do the map again but I don’t want the same thing to happen because it’s a longer map and this is at the very end before the exit! Thank you! 

Perhaps the linedef in the room outside the map for the monsters to teleport is one-use only?

I looked at the map in an editor, and see nothing wrong with it.

Occasionally monsters walk back and forth for a while and don't cross a teleport trigger line, but they usually do it eventually.  You may have just had that happen, though if it went on for a really long time (minutes) then I don't know what it could be.

If it happens again, you can use the automap cheat to show where it is and where it is going, it will be the green triangle.

4 hours ago, andrewj said:

Occasionally monsters walk back and forth for a while and don't cross a teleport trigger line, but they usually do it eventually.  You may have just had that happen, though if it went on for a really long time (minutes) then I don't know what it could be.

This is definitely what happens sometimes and it's especially notable with zombiemen due to how slow they move, as well as lost souls and such. Sometimes you get two monsters who line up with each other and go back and forth for some reason.

One way I found to coax them (assuming you have iddtx2 on and can pinpoint where the problem monster is) is to go to an area beyond the closest corner of the teleporter closet. So say the monster is going back and forth in an E/W style, and you go to an area beyond the SW or SE corner and stay there. The monster may either go E/W again once it hits the closest corner or decide to go N/S.

A good way to alleviate this if you're mapping teleporter closets is to make another WR teleport linedef that's perpendicular or at least angled in a way so that the monster that goes back and forth will inevitably come in faster. There's of course other ways too.

7 hours ago, andrewj said:

I looked at the map in an editor, and see nothing wrong with it.

 

Occasionally monsters walk back and forth for a while and don't cross a teleport trigger line, but they usually do it eventually.  You may have just had that happen, though if it went on for a really long time (minutes) then I don't know what it could be.

 

If it happens again, you can use the automap cheat to show where it is and where it is going, it will be the green triangle.

Well I’m playing on the PS4 version so I can’t really do that unfortunately. I’ll just go through it again

I just went through the whole map again, and quicksaved at the end. One time it worked and everyone teleported in, but then I reloaded and did something slightly different, went somewhere else while they were teleporting or something, and then  the same problem happened again. So something must be triggering him to not teleport

9 hours ago, LucidLocomotive said:

Well I’m playing on the PS4 version

Is that the same as the PSX one?  I think that port has a bug which corrupts the blockmap occasionally and allows monsters to walk around outside of the map -- which would explain what happened to you.

54 minutes ago, andrewj said:

Is that the same as the PSX one?

No. You seem to be quite behind the curve, we have classic ports of the PC Doom1&2 with console support for downloading select mods on the Switch, Xbox and PS4. For several months now, this isn't exactly recent. 

10 hours ago, andrewj said:

Is that the same as the PSX one?  I think that port has a bug which corrupts the blockmap occasionally and allows monsters to walk around outside of the map -- which would explain what happened to you.

No it’s just the original pc version porter to PS4 via the “classic doom” source port by Bethesda 

Don't know the reason for this case, but I found something with mass 90 or less, probably anything less than 100, can pass over a teleport line without teleporting sometimes, at least when shoved by a rocket or berserk punch, in vanilla doom.exe.   Haven't had this trouble with any ports.

Only thing I can think of is something blocking the teleporter itself, but that'd only apply to the player's telefrag invulnerability (except on MAP30). Monsters will happily telefrag each other.

18 minutes ago, Dark Pulse said:

Monsters will happily telefrag each other.

Nope. Only happens on MAP30.

2 hours ago, Edward850 said:

Nope. Only happens on MAP30.

Then if something is blocking the portal, that could be why.

On 4/27/2020 at 3:48 AM, LucidLocomotive said:

What can cause an enemy not to teleport?

• Teleport linedef being unreachable
   
• Teleport linedef being non-repeatable
   
• Teleport destination being blocked
   
• Poor teleport closet construction causing severe delays, or getting monsters stuck in a loop where they don't cross the teleport linedef again

These are the usual reasons, and any other inconsistency is usually some sort of variation thereof.

Stuff like "doesn't teleport at times due to not having enough mass" sounds "iffy" to me, and I'd like to see some actual proof for this kind of theory instead of anecdotal evidence that says "well, sometimes it happens, and sometimes it does not". Might as well be the case that these observations have been made when a destination was blocked, which the player couldn't see at the time, or the monsters being accelerated to a point where linedef skips occur (in which case "mass" is not the main reason, but merely a contributing factor to said acceleration).

There are no "triggers" required to fuck up the functionality of a teleport closet. It's all down to how well the closets are built, and many maps, even modern ones, employ fairly poor closets, which don't provide consistent results. That being said, the older the map, the more likely it is that some parts of it aren't constructed particularly well, or at least not "ideal".