Advanced use of a very rare bug in speedrunning

[Hugh Everett]

Could it be possible to improve some runs using the clipping bug introduced in hrodd27.lmp? Use your imagination: just run (straferun/slide/walk) 10 000 000 times towards various infinitely tall objects to make a hilarious quantum jump trough bugspace! And then ofcourse: press the end switch.

[Grazza]

The bug is very rare and I don't believe anyone knows of any reliable way to trigger it. There are also severe limits on what the player can do when this bug occurs.

In fact, that demo is itself a pretty good example of those limitations - if the player had been able to exit, I am sure he would have done.

[admin]

The player definitely cannot trigger the exit line when noclipping. I'm not sure if pressing a switch is even possible either.

IIRC this bug is so obscure PrBoom doesn't even recreate it.

[VinceDSS]

I remember reading some stuff about that (maybe from cph, not sure tho). It said that when this bug occurs the memory starts to get trashed / corrupted, making everything noclip being a symptom of the memory corruption. So if the exit switch code gets trashed, you will not be able to trigger it
It prolly happens all the times tho I don't remember anybody exiting when that bug happens, it happened a couple times to me ... never been able to exit.

[Opulent]

there is only one instance of this working in the player's favor.
Ledmeister on Blacktwr -- he dies in the exit-level slime to get an unbeatable, unbelievable time.
You cannot 'use' anything when this bug occurs... it is a cool thought though.  :)

[VinceDSS]

thanks Op ! I actually never seen that demo just heard about it.

So if someone could trigger that bug in e1m8, he could crush Adam's time with a nice margin

[admin]

Vince: maybe... though OgreSlayR has the UV speed record nowadays

I also remember cph speaking about the cause of this bug being memory corruption.

So basically what we have here:
- a bug which happens very rarely AND entirely randomly
- the noclip player not being able to trigger anything
Hardly any useful, isn't it 8)

I also have a MAP01 DM where this happens, pretty funny stuff.

I only experienced this bug once in my career, BTW, it was HR MAP19, I was walking noclipped around for a couple of minutes, then DOOM crashed and didn't write a .lmp  >:(

[Radeg]

It happened to me twice, DooMII map03 and map24, it always had something to do with chaingunners, maybe I still have got the demos, i'll let you know...

[Grazza]

Here is the post where Op quoted cph's explanation of this bug.

I mucked about recently with another "player becomes ghost" phenomenon, in which the player can use switches. However, this requires the player to have exited a previous level as a zombie, which requires a voodoo doll. There aren't many of those in the compet-n maps, and AFAIK they are not in a place where they can be "usefully" damaged (just used to collect items for the player, or to be telefragged outright).

[VinceDSS]

personally, I got it in coop map03 and a couple times in NM e1m3.

[AdamW]

first time it happened to me was e1m4, don't remember the second...

[df]

Happend to me at least 6 times ... always when we where doing long 4-way dm's on map01.
(Back in '98 or somthing?)
(Of the times it happned, none of us could use the exit switch.)

[Yet another Compet-n fan]

So, this clipping bug seems to be mostly useless. Nevertheless, I had an idea: because of the interesting fact, that all the monsters start clipping, lv30 pacifist run might be possible. Just make the bug happen and let the monsters kill the romero-head-thing. Crazy me...  ::)

[myk]

It does seem to be related to there being many gunners (Shotgun guys, Zombiemen Heavy weapon dudes, or the Spiderdemon) on the map. And if it is, then it won't happen on Map30.

[Grazza]

That does seem to be the case (though in blackbug.lmp it didn't need too many hitscan shots to be fired for the bug to be triggered). But anyway, even if the bug did somehow occur on map 30, I don't think you could use it to kill the boss brain, since you can't actually reach it. As I said above, there are still restictions on ghost movement - it's not pure "noclipping".

[Jaakko]

Speculation:
You can trigger the bug using your own chaingun. (This has been left unnoticed because advanced players very rarely run towards walls guns blazing. It is sick to do such a thing!)

Facts:
1. E1m8 has a chaingun and an exit slime.
2. Nobody has the patience to try these kinds of things anymore.

[xit--vono]

I do believe in requiem map04 it's possible for a fireball to go through a wall and injure a ghost.  Anyone want to look into this?

[Johnsen]

only if you promise to look into the barrel of a loaded shotgun held by someone suffering the occasional finger twitch.

[VinceDSS]

LOL, andy is an eternal joker !?  ::)

[AltimaMantoid]

I've actually had this happen a very few times, usually with maps that have a lot of monsters. It's happened to me three times on HR24, once on H227 (recently, I just suddenly fell through the floor and off the map), and then a few other levels I don't remember, but I remember once on lv02...

As far as my explanations, I don't have a clue...