Making zombies come out of the ground [L4D]

Hello there, I am currently making a map where I want the zombies to be able to dig themself up out of the ground, I have managed to do this by simply making a brush that has no collision, and then adding a player clip over it so it gives the illusion that you can walk on it.

It works pretty well but I am wondering is there anyway to make the zombies only be able to go up and not down, the way it is right now the zombies climb up but as soon as they run over the area they fall down and have to climb up again. Is it possible to change this? I am still learning mapping :smiley:


Zombies are retarded, They fall into holes. It seems very logical to me.

No but i mean they fall in to their “graves” again, i have made graves from where they “climb” up from there are many corridors under each graves so it looks like they are climbing up from their graves but really they are just running in a underground corridor and then climbs up trough a brush without collision. Im sorry for being bad at explaining :o

Don’t think it’s possible to do one-way collisions.

Can’t you texture the top side of their brush with clip and the bottom with nodraw?

Maybe make it player_clip, and make the top surface the dirt texture. Would that work?

To the above 2 posts, NO


You would have to do something with the nav mesh so they would avoid that area.

Is it possible to have a trigger set off once a zombie climbs out of his “grave” and once it’s triggered it causes a npcclip brush to appear

Yeah, just make a trigger around his grave that has only the NPC tab checked, and when triggered makes a nodraw brush on top of the grave. This could give you problems if another NPC triggers it before the zombie climbs out, but idk if there’s a better way to do it. Well, actually if ur using scripted sequences to make the zombies climb out, you can add an output to them so that when the sequence is over, the nodraw brush appears.

Player clip and func_illusionary? Func brush w/o collisions?

Just mark the mesh around the hole with “mark AVOID” and make sure that the mesh is only connected from down to up, this way they can only climb up and not down.