L4D: Zombies not spawning on rooftop

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L4D: Zombies not spawning on rooftop

Post by Doc_Brown » 29 Jun 2017, 14:55

The finale map I've been working on is set at an abandoned rescue zone, a rectangular fenced-in area with a building forming one of the sides. The idea here being that even if you put your backs to the wall, the zombies can climb over the fences or drop down from the rooftop.

However, in practice the zombies simply refuse to spawn on the roof at all, making the finale painfully easy to beat. As far as I can tell the nav mesh is set up correctly, and I've played around with various combinations of Obscured, Finale, Battlefield, etc, but nothing seems to work.

It doesn't seem to be an issue of distance, either, as you can see zombies spawn in on the complete opposite side of the map (which is further away in units than the roof of the building is from the ground). Am I missing something? Is there any way to force a spawn location preference?

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Re: L4D: Zombies not spawning on rooftop

Post by thekiller901 » 29 Jun 2017, 21:14

I have little to no experience programming finales (and you've probably already checked these) but;

Is the navigational mesh on top of the building connected to the navigational mesh of the play area?

Is there anything like a tool brush or something that's too low on the top of the roof which would make the area too small for Infected to spawn to that location?


If these don't help, would it be possible to ask for pictures of the area both from the editor and in game?
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Re: L4D: Zombies not spawning on rooftop

Post by Doc_Brown » 30 Jun 2017, 22:26

Well, here is what we're dealing with:

Image

The area with the red light is where the trigger for the finale is, and with that being the only non-fence boundary, players are likely to try holing up there.

Image

This is a view of that rooftop from the editor. I've hidden a few elements for visibility, but the skybox runs along the very top there. That would leave 128 units of space on the upper area, and 256 on the lower sides.

Image

Finally, above you can see the nav mesh and the various connections. I thought maybe the connections were in the wrong direction, but even reversing them or linking the areas in both directions didn't change the end result.

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Re: L4D: Zombies not spawning on rooftop

Post by thekiller901 » 01 Jul 2017, 04:16

I won't swear to it, but I think the 'EMPTY' tag might be causing the problem.

Maybe try removing that tag and marking your roofs 'NOT_CLEARABLE'?


Although I wouldn't recommend doing so, if all else fails and you really want to have Infected spawning up there, you might be able to get away with using a couple ‘info_zombie_spawn’ entities connected to a ‘logic_timer’ entity.
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Re: L4D: Zombies not spawning on rooftop

Post by Doc_Brown » 01 Jul 2017, 20:59

Unfortunately I've already tried without the EMPTY tag, and it didn't help. I just worry it might be some particular combination of attributes, because finding the right grouping would be a matter of sheer luck.

I may give info_zombie_spawn a try, though I worry it won't work very well with the cadence of a finale (pauses between hordes, the tank battles, etc). Thank you for your help, though, I do appreciate it.

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Re: L4D: Zombies not spawning on rooftop

Post by Rectus » 09 Jul 2017, 16:09

Try using a scripted finale, and setting your finale script to have the DirectorOptions PreferredMobDirection set to SPAWN_LARGE_VOLUME and ZombieSpawnRange high enough to cover the distance to the roof.

It's also possible that the Director isn't considering the drops of the roof vaild and doesn't generate the nav flow from there. You could try adding a way down with smaller steps in between.

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Re: L4D: Zombies not spawning on rooftop

Post by Doc_Brown » 10 Jul 2017, 13:20

One of the reasons I'm hesitant to rely on a scripted finale is that the players could just as easily choose to hole up on the complete opposite side of the map. If I'm forcing most of the horde to spawn on the roof, it would make putting your backs to the fence the easy way out. The ideal would be the director being smart enough to spawn close to the players regardless of where they make their stand.

I will give the step-down option a try, though. Part of the inspiration for this finale was the third map of Coal'd Blood, which features a crescendo event set on a large descending lift (meaning that the zombies spawn up top and then come raining down on the players). It's possible the director is being fooled by the initial nav_mesh into thinking it's only a short drop. Maybe that's the trick--literally tricking the director...

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Re: L4D: Zombies not spawning on rooftop

Post by Rectus » 10 Jul 2017, 14:47

Having a finale script won't really change any of the spawn logic by default. Unless you use a gauntlet finale, the Director can spawn infected in any part of the FINALE area. I'm not actually sure if ZombieSpawnRange does anything in finales, but PreferredMobDirection = SPAWN_LARGE_VOLUME is used in the Dead Center finale, so it might help the director to choose areas above the survivors.


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