Any Way to Clip Up Through a Ceiling?


Would there be any way to clip upwards completely through a ceiling? I realize that’s there probably isn’t since I’ve never seen or heard of it being done in a run before. However, As you know, clipping downwards through a ceiling is possible from oob without the use of a prop or anything. So that leads me to this:

[font=verdana, arial, helvetica, sans-serif]The downward clip at the end is completely possible and pushes you back in bounds every time(as far as i’ve seen) I only used noclip because demos stop recording when you save/load.

So, in regards to c17_01, if there was some way to get onto the ceiling of the lab it would not only be possible to skip the cutscene, but easy too. Of course, if horizontal prop clip becomes reliable enough this become’s irrelevant.

Also, sorry if anyone’s already found this before; just thought I’d share. Comments are welcome, thank you.


I remember seeing a highlight clip on someone’s twitch where he got stuck in the wall of the elevator shaft during the map change and then started going upwards when he save/loaded


In Old Engine version of HL2 you can save buffer upwards. Also you can clip through ceilings in 4104 versions of Source, but I’m not sure if HL2 was ever offically ported to it. This is called CEOOB (Crouch Entry Out Of Bounds). I’d link a video but I can’t find one.


Found a video


That’s very interesting, I’ll have to see if I can get that to work in the current engine. Would anyone have an idea on how to get CE-OOB to work? From what I got from the video, I’m not sure if you’re just spamming crouch and jump or if there’s specific timing involved.


There’s probably a specific timing to ceoob but you can get it by just spamming crouch. Nobody has done it on 5135 though so it’s probably not doable in HL2.


Z1m kinda did it in Portal, however in a slightly different way and no one understands what happened there.


I did a bit of code digging but all I could find was this
which could potentially teleport you up to 36 units upwards if you get stuck in something while crouching.
but to get through the ceiling in c17_02 you have to teleport a minimum of 45 units so there must be something else going on. I guess I’ll keep digging.


If we ignore the checks the engine does to see if you can unduck (which seem to fail somehow) what could be going on is that you first make a regular duck on the ground, which will move your hitbox down to your feet, and during this move up enough that you shouldn’t be able to stand up (but as I said we ignore these checks) and as you do this you have enough speed from sprinting or jumping or whatever that you reach a vertical velocity >420 (if you go faster than this the engine says you’re not on the ground anymore) when going up the slope and somehow unduck and duck really quickly (before the engine calls [font=consolas]FixPlayerCrouchStuck) you would move your hitbox up to your face (the engine does this if you crouch in the air) so you would essentially teleport 36 units upwards, get stuck in the ceiling, and because of this teleport another 36 units upwards.

[font=consolas]This is just a theory I have and I have yet to find a flaw in the checks the engine does.


^This is probably the most accurate description of CEOOB I’ve seen to date. Unfortunately, it can’t be done on any versions of Source past the May 2010 update. You can do it easily on the 2004 version of HL2, but it won’t do anything beyond pushing your camera through the brush; when I originally discovered CEOOB, I thought this would be a good technique to check if the glitch could be used somewhere, but it was so hard to reproduce that it didn’t matter. I’ve only ever fully gotten it twice, but it was on whatever version of Source Protocol 14 is. Not to mention that it was also on a mod, so that hurts credibility, but I’m sure it could be done on an unmodded version. If you really want to attempt to dabble into it, good luck. The movement just to perform it always hurt my fingers after about 15-20 minutes, so what’s on that video is as far as I’ve ever been. However, don’t even bother attempting it on more up-to-date versions of the game because I guarantee it won’t work. I imagine it could be possible on the 2004 version of HL2, so that might be somewhere to look into.


I got CEOOB on the preupdate version of ep2 in the same place where Centaur1um got it so I can confirm it works on unmodded versions of the game as well.


Just had a thought that maybe you could clip upwards by damageboosting once you’ve got stuck somehow, then saveloading.


Oh, that’s awesome. Do you have a video?


Unfortunately no.


anyone tried doing a quantum crouch and saveloading?


Yeah it doesn’t do anything.


Have you tried that in the older version, too?


You can’t quantum crouch in older versions of new engine.


Oh, balls.


Is there something special you have to do when performing ceoob, like do you just spam crouch or is there a timing to it?