Weird demos

I think I got it now. The version number (0x6f) in the header should have tipped me off. This must be a longtics demo, isn't it? No wonder it makes vanilla and LMPC freak out. Boom-LMPC doesn't seem to read it correctly either, even with "-l".
But you have nothing to worry about. Your demo will play properly with any engine that supports longtics demos - the v1.91 hack, Prboom-plus, Choco and Eternity.

Yes, it is longtics. Thanks:)

Interesting. Not sure how longtics contribute to this, can anyone verify it works with shorttics as well?

The -longtics parameter seems to change the gliding rules, check out my Resurgence demo in the glide thread for another example: http://www.doomworld.com/vb/post/1300609

Maybe bruteforce could find an angle which matches with the longtic movement because the physics should be the same. Only the angle of movement is extremely sensitive?

Edit:Nvm, there are quite many different angles where the void glide happens.... but bruteforce time anyways :-P

Heh, Doom1 E2M1.

Turbo was used.

ripdoom.zip

Interesting indeed.

(And they are both built runs if it wasn't clear)

e1m8-hmm.zip

Looper said:

[e1m8 demo]

Well that's one thing checked off the bucket list, though not in quite the way I'd imagined.

Looper said:

[e1m8 demo]

Is it possible to do the same thing on e2m5?

Kpa6 said:

Is it possible to do the same thing on e2m5?

No because of the height difference.

Got it.

Looper said:

[e1m8 demo]

I guess this will save further time in an E1 TAS, since you can skip the two boxes of rockets that e1uv-345 picks up in E1M6 (or pick them up and spend rockets more freely in E1M7)?

(Speaking of those two boxes of rockets, not that it matters now, but I wonder if it would be faster to get them in the swastika room in E1M4 instead of E1M6?)

Fredrik said:

(Speaking of those two boxes of rockets, not that it matters now, but I wonder if it would be faster to get them in the swastika room in E1M4 instead of E1M6?)

No because the better way is to force one of the monsters to open the door for the player which means you don't have time to pick useless things :D

improcket.lmp - Heroes' Tales MAP23 -complevel 4
"-skipsec 23"
An Imp takes a flying lesson from an Archie

necroimpse.lmp - Switcheroom E1M5 -complevel 3
"-skipsec -75"
An attempt at a Pacifist run ends in something indescribable


upthestairs.lmp - XAOS.WAD MAP07 -complevel 2
"-skipsec -25"
An extended death slide *up* a long curving staircase.

You can also watch the extended versions here.

edit: Replaced attachment. The original Necroimpse video was giving me headache with 3rd-party content warnings and ads. Replaced the audio with a slowed down version - problem solved. ;)

weird-2015-03-08.zip

I have a TNT 32 tyson attempt, where a demon is continuously biting a trapped revenant and keeps missing it. I knew bullets can miss like that, but I didn't know melee attacks can also miss. It was very strange when suddenly there was a continuous bite sound coming from somewhere. This is probably not worth your time, though. It takes 32 minutes until it happens.

tnt32-continuous-demon-missbite-happens-at-around-32-minutes.zip

Lol, the glide happened again.

e3m1-again.zip

Haha, that's one way to end a run

Aqfaq said:

I have a TNT 32 tyson attempt, where a demon is continuously biting a trapped revenant and keeps missing it. I knew bullets can miss like that, but I didn't know melee attacks can also miss.

That's interesting, since the normal running-around code calls P_CheckMeleeRange() to see if it should go into the melee attack state, and then the Demon bite frame also calls P_CheckMeleeRange(). The only thing I can think of (without watching the demo) is that the Revenant just barely got close enough to make the Demon go into bite mode, but immediately moved away again before the Demon actually bit (similar to how you can avoid Demon bites yourself by backing up before it connects).

It is because there's so little room around the skelly to move, blocked by walls and the demon, so the attack speed and the tiny movement pattern got in a perfect sync to force the demon always attack instant but never hit. So basically what Linguica said.

Nonsense. The skellington just watched PRO DOOM MONSTER STRATS and learned how to bait the hungry mouths of those unrelenting shit heads.

dew said:

PRO DOOM MONSTER STRATS

No wonder revenants are so agile and cunning...
http://i.imgur.com/FlIWiV1.png

Shameless plug?

Not weird but imho not so obvious, in vanilla doom player's corpse can conserve momentum!
I died while pushing against imp and sergeant,
and when sergeant moved aside my corpse was propelled forward.

mm24_corpsemomentum.zip

Today i was recording a demo for doom 2 beccause i wanted to show how i played, shooting things in a row, popping behind walls, and so on. But this failed beyond belief and i ended up with an awkward fluke because i was not used to prboom its mouse handling and compatibility levels anymore. It looks awkward and to me comedic.The attached demo shuld work but if anything is wrong, let me know.

ffrn-001.zip

Spoiling my work here, plays back with doom2
One demo shows all ghost bug happening in map04, other shows me being able to die and exit at the same time in map02, this one surprised me I didn't know it was possible

ns01wut.zip

Never_Again said:

upthestairs.lmp - XAOS.WAD MAP07 -complevel 2
"-skipsec -25"
An extended death slide *up* a long curving staircase.

Now this is truly weird: I see a different map than the one on your YouTube run, you shoot some chaingunners and after a while you die, then you try again, shoot them again, etc. But after a while, it desyncs. You sure you got the right map here?

Never_Again said:

necroimpse.lmp - Switcheroom E1M5 -complevel 3
"-skipsec -75"
An attempt at a Pacifist run ends in something indescribable

o_O

At what point, roughly, does it desync? Doesn't "-skipsec -25" work for you? It's a lazy FDA, with something like ten deaths, perhaps you mistook lame playing for a desync? ;)

Aaah I missed the -25 instead of 25 (25 is in the middle of a death sequence lol). Thanks. Funny thing is, I actually did think it desynced because you died and kept pushing walls. After a while though, I was convinced, because it seemed to get worse and worse. ;)

Ancalagon said:

being able to die and exit at the same time

That's cool. Having TASed many old console games, I can say that this is a very common type of phenomenon. Doing something on the same frame as something else is happening can often result in glitchy behavior. In a TAS environment such tricks and glitches are very easy to find and reproduce, but this is extremely rare when playing normally. Hypothetically there could be a wad where this trick saves time as it refills health and gives 50 bullets.

Ancalagon said:

all ghost bug happening in map04

At gametic==6911 when a sergeant at (-499, 1127) kills another at (-600, 1124) there is a massive intercepts overflow. The kill shot adds nearly two hundred intercepts - three dropped shotguns are added over sixty times each(!)

Further investigation shows P_PathTraverse getting stuck in a loop on one blockmap square (9,6) == [(-848,1016),(-720,1144)] due to some kind of numerical error in the code stepping across the blockmap squares covering the trace line. Neither ((yintercept >> FRACBITS) == mapy) nor ((xintercept >> FRACBITS) == mapx) is true, so mapx and mapy are never updated, and the thing loops until it hits an arbitrary limit of sixty-four iterations.

Ancalagon said:

die and exit at the same time in map02

User input is processed in P_PlayerThink (calling P_UseLines once when it first detects a use key press) before P_RunThinkers processes every other mobj. So the exit line is activated, setting gameaction to "level completed", but this is not processed until we return to G_Ticker at the start of the next gametic. In the meantime the rest of the current tic (gametic==4022) is run, during which the sergeant, unaware the world has already ended, shoots the player. It's just a very precise case of timing.

Aqfaq said:

Hypothetically there could be a wad where this trick saves time as it refills health and gives 50 bullets.

I am sure it could be exploited, but requires the first use key press ticcmd to appear on exactly the same tic as the damage is taken. I imagine this would be prohibitively difficult to those not blessed with superhuman reaction times -- or more likely, available only to demo builders.