Mysteries of Doom

[Looper]

geekmarine said:

Oh yeah, I don't know why I forgot to mention him. I always felt so bad for the poor bastard. Never had a chance, AND he's trapped next to a barrel of highly volatile chemicals (what is that nukage in the barrels, anyway?).

That shotgun guy is insane sometimes. If you see him shooting, he will keep shooting as fast as possible. I'm not sure when he starts his shooting spree but if you don't take him down ASAP, he will take you :P

[Jaws In Space]

geekmarine said:

Why is there a barrel stuck halfway in the wall in MAP02? That one drives me mad to this day. Part of me loves it, but part of me wonders how it was missed when it's so obvious.

For some reason the entire map was shifted in version 1.8 to be closer to the 0,0 coordinate, along with all of the things. It caused some issues though as some of the floor flats became misaligned. So in version 1.9 the map was shifted again, but they forgot to move the barrel & shotgun guy.

[dew]

Da Werecat said:

Linedefs are being activated when the center of the object passes them. I don't think that boundaries matter in this case.

This. If there are positional checks, they don't apply to the whole bounding box. Effectively, skips seem unreliable and their difficulty can range from trivial to impossible/TAS-only. Orthogonal lines are definitely the most susceptible, so their "range" for trigger checks must be the smallest. In this 1024Claustrophobia demo I manage to skip two linedefs a few units afar at once (then one on the way back again, hehe).

Non-orthogonality certainly helps hide the issue, but it's not a complete fix. Just a few days ago, I accidentally skipped a (just slightly) non-orthogonal west-east linedef while sr40ing more or less north. The famous rambobones/Sylvain Chabert Doom 2 TAS movie features a rocket boost over a linedef tilted by 45deg in map08, but that's deemed purely inhuman. So yeah, skips are a little bit mysterious and it'd be nice to have one of the source wizards do a little code diving. :)

Looper said:

That shotgun guy is insane sometimes. If you see him shooting, he will keep shooting as fast as possible. I'm not sure when he starts his shooting spree but if you don't take him down ASAP, he will take you :P

This happens oftentimes when monsters get stuck over edges (so over lifts in vanilla). It's like the engine realizes they can't move, so they do the only action left to them. Then again, it's rather inconsistent, so I dunno.

[jmickle66666666]

Hurricyclone said:

i never found an explanation as to why when you kill imps/zombies on high ledges, they sometimes fall forward towards the player. seen it happen very often myself.

When doing a speed demo for d2twid map02, it was necessary to shoot one of the zombies off the ledge towards you, triggering a linedef. I found that this is reliable when the enemy is moving towards you when you kill it.

[Gez]

Hurricyclone said:

i never found an explanation as to why when you kill imps/zombies on high ledges, they sometimes fall forward towards the player. seen it happen very often myself.

It's a very deliberate effect. We had a recent thread about it, so go read that for more detailed explanations.

[NuMetalManiak]

seriously? it's just randomized?

also I didn't know that Doom was inspired by Westerns. Cool.

[fraggle]

Gez said:

It's a very deliberate effect. We had a recent thread about it, so go read that for more detailed explanations.

I wasn't even aware of this. Cool.

[40oz]

Never heard of linedef skips. I watched the demo Grazza linked to and watched the part he described over and over, I didn't get what was happening until I read this thread over a few more times.

Linedef skips are when the player manages to cross a line (one that should do an action, to confirm for sure whether or not it was skipped) without the engine recognizing that he had crossed it?

Am I understanding that correctly? I think I managed to do that once in my FDA of Jimi's Mercuria Experiment on that level that resembled Caged. I stepped onto a teleport pad I had used once before, and it didn't work until after I stepped off of it and stepped back on again. Would that be an example of a linedef skip?

[4shockblast]

40oz said:

Linedef skips are when the player manages to cross a line (one that should do an action, to confirm for sure whether or not it was skipped) without the engine recognizing that he had crossed it?

Am I understanding that correctly? I think I managed to do that once in my FDA of Jimi's Mercuria Experiment on that level that resembled Caged. I stepped onto a teleport pad I had used once before, and it didn't work until after I stepped off of it and stepped back on again. Would that be an example of a linedef skip?

Yes, what you did is a linedef skip. Teleport linedefs are relatively common to skip (probably because they are often orthogonal).

[didy]

40oz said:

I stepped onto a teleport pad I had used once before, and it didn't work until after I stepped off of it and stepped back on again. Would that be an example of a linedef skip?

This happened to me too.

My Mystery:
the shaft (sector 39) in map01 when you enter the secret room (sector 28), it's like the shafts in the khufu pyramide for me, which functionalties are not yet fully known.

[Doominator2]

I'm still wondering why the Doomguy is immune to his own rockets.

[FTM]

Doominator2 said:

I'm still wondering why the Doomguy is immune to his own rockets.

I think its because otherwise its own rockets would explode on him the very moment he fires them.

[General Rainbow Bacon]

Map 04 "Wormhole" in TNT has two random crushers outside the map that do nothing from what I can tell.

[Koko Ricky]

If I recall, those crushers make for some pretty scary ambient noises in the PSX version.

[StevieWolfe]

General Rainbow Bacon said:

Map 04 "Wormhole" in TNT has two random crushers outside the map that do nothing from what I can tell.

They're just to make machinery type noises in that underground section so it sounds like a generator is running down there. Its a simple and stupid trick I've found works well in maps where you want that "idle engine/running backup generator sound effect.

[MajorRawne]

Here's a mystery for you. If Carmack was such a genius, and I do agree he was, how come Doom is so full of bugs, errors and weirdness? Part of the charm, maybe, but on some Shores of Hell maps I needed to drop my trousers and slap my cheeks right in the faces of Pink Demons to get them to wake up. I'm prepared to concede that Carmack was entering a new frontier when programming Doom, but even a casual playthrough of Ultimate Doom seems to reveal strange things.

[Marnetmar]

MajorRawne said:

Here's a mystery for you. If Carmack was such a genius, and I do agree he was, how come Doom is so full of bugs, errors and weirdness? Part of the charm, maybe, but on some Shores of Hell maps I needed to drop my trousers and slap my cheeks right in the faces of Pink Demons to get them to wake up. I'm prepared to concede that Carmack was entering a new frontier when programming Doom, but even a casual playthrough of Ultimate Doom seems to reveal strange things.

[dew]

MajorRawne said:

Here's a mystery for you. If Carmack was such a genius, and I do agree he was, how come Doom is so full of bugs, errors and weirdness?

I seriously don't know whether to mock you, pity you or patiently explain how is bug formed.

[40oz]

I'd say its far from full considering its competitors weird 2.5D engines. Maybe you could do a thorough analysis of the physics and rendering properties of games like mage slayer or last rites or witchhaven, pursuit of greed, or duke nukem 3d.

its weird you said that because I was seriously just thinking about how durable the engine is this morning.

[MajorRawne]

There's no doubt the engine is durable, I mean the basic game is still going strong today. I'm a bit surprised there weren't more game companies trying to license the engine.

I never really looked at the state of computer gaming in 1993. The Megadrive, SNES, Master System and NES were doing very well and 2D has always been the best perspective for any platformer. Suddenly Doom appeared with a world you could inhabit. It made all other game types - not just games, but genres - feel obsolete. It's probably a wonder that there weren't more weird bugs and issues, especially when you consider Doom started life more like an RPG than a straight shooter.

Maybe that's Doom's ultimate appeal? There are no missions, no cutscenes, no flashbacks, no upgrades, no levelling up. Doom is pure. It never loses sight of its goal. Nothing whatsoever is allowed to get between the player and the game. No modern FPS can say this; in fact, most modern FPS games tend to spend as much time displaying visual prowess as they do actually being playable, and for some reason, the ones that do allow you to upgrade your stuff often only allow that stuff to be used in multiplayer mode??

[Phobus]

didy said:

My Mystery:
the shaft (sector 39) in map01 when you enter the secret room (sector 28), it's like the shafts in the khufu pyramide for me, which functionalties are not yet fully known.

Its a sound tunnel (from the cage next door) so that the two imps will come out of there and attack if they hear you firing. Joining sectors wasn't a thing back then, so that's how they got round it. It probably also works as a clue pretty well.

[Koko Ricky]

A few of my personal mysteries:

1) What the hell is that green "evil eye" ornament supposed to be? It looks pretty weird when translated to 3D, ala Doomsday's models.

2) Why aren't there more linedef actions in vanilla? It's weird that there's a "scroll texture left" but not "scroll vertically up/down" or even "scroll texture right." There's also some walk once/walk repeatedly actions that I wish had been implemented, to achieve some interesting transformational effects. I also think there should have been a switch function for teleportation. Adding these actions in the original game wouldn't have been difficult.

3) Was there any reasoning behind giving certain enemies different colored blood, or was this purely artistic?

[Maes]

GoatLord said:

2) Why aren't there more linedef actions in vanilla? It's weird that there's a "scroll texture left" but not "scroll vertically up/down" or even "scroll texture right."

The lack of up/down scrolling can be partially justified by noting that scrolling a column-based texture horizonally (and to the left) is far easier, computationally (and easier on the limited CPU's cache), than scrolling it vertically. Vertical scrolling would just kill performance. For the same reason, right scrolling would equally be a "cache troll", though I would find it surprising if it was so bad that they didn't even leave it as an unused feature.

[Ledillman]

1) Sometimes i think is "God's eye" watching our hero beating hell, but it says "demonic eye" or something in DB so people complain when i say it :-P

2) No idea, but I guess ID didn't need them at the time they finished the levels and stuff. I tought the same years ago when i started mapping.

3) Probably a purely artistic thing! and i wish they made green and blue blood falls when you shoot at the barons and cacodemons.

[Krazov]

Ledillman said:

i wish they made green and blue blood falls when you shoot at the barons and cacodemons.

I read somewhere that it was planned but postponed and later there was no time. Mods Beautiful Doom and Zero Tolerance for ZDoom makes blue/green blood. And Doom Retro does it.

[Koko Ricky]

I believe Expanded Doom does as well.

[plums]

There are several ZDoom mods that change the blood colour, there's even one that does that and nothing else if you want more of a vanilla-like experience.

Crispy Doom is another port that changes the blood colour.

[Zed]

plums said:

There are several ZDoom mods that change the blood colour, there's even one that does that and nothing else if you want more of a vanilla-like experience.

I could also mention that if you just search for blood + color/colour in the forums you should get some relevant hits. I personally use this one, courtesy of glenzinho.

[geekmarine]

Correct me if I'm wrong, but you can accomplish the same thing as a sound tunnel by having the sector the hidden monsters are in be the same as the one where you want them to be alerted, right? You know, two separate enclosed areas, all with the same sector label? Assuming I'm not misremembering, I kinda wonder why the the guys at id themselves never figured that out. Just seems a more elegant solution, and in some odd way, more aesthetically pleasing, to just have two rooms have the same sector number rather than making a tiny passageway to connect them and then try to hide it.

[Zed]

geekmarine said:

making a tiny passageway to connect them and then try to hide it.

I'm glad you mentioned this, I don't know if what I'm about to say is related.

I always wondered about this little passage:



Anybody knows why it's there?