Things about Doom you just found out

[Frost-Core]

I found out that these are the same, just slightly modifiied (i may be wrong) :

[nrofl]

35 minutes ago, Frost-Core said:

I found out that these are the same, just slightly modifiied (i may be wrong) :



What do you mean by the same, do you mean the hand sprite?

[Frost-Core]

Just now, nue said:

What do you mean by the same, do you mean the hand sprite?

Yes, of course

[Optimus]

I noticed all UAC cylinders in this area (and also in a previous room) had few pixels cut near the C. It was so identically that I initially thought the default texture is wrong, but later I opened the editor and they all had the same texture offsets that created the effect, copy paste of the exact same prefab.

 

[RetroAkaMe]

Petition to make this topic pinned. This is genuinely pretty cool to check and deserves more attention.

[Dragonfly]

With 10 years of content across over 300 pages, I don't think anyone's had trouble finding this thread.

[Maes]

There's a an official (?) UV-MAX run of CYBIE.WAD:

 

 

[Lippeth]

I just found out that monsters go back to their idle state when loading a game that was saved out of their sight line. I can't believe I never noticed that.

[peach freak]

On 4/23/2022 at 12:34 AM, Lippeth said:

I just found out that monsters go back to their idle state when loading a game that was saved out of their sight line. I can't believe I never noticed that.

 

They do go back to being idle, but I believe the saved game will remember whether or not the monsters had been idle at the time of your saved game, so any monsters that were active (either they saw you, heard your gunfire, etc) will re-awaken on your first shot after loading a saved game, even if there are sound-blocking measures between you and some of the monsters.

[thiccyosh]

When in Ultimate Doom or Doom 2 a monster opens a door, the player is unable to close it again until the door has fully opened, probably a band-aid fix from Id to prevent Doorfighting. In Doom 64 however, you can always just slam the door shut when any demon tries to open it.

 

That was your Doom fun fact of the day.

[RjY]

The only visible instance of GRAYTALL in the whole of doom2.wad.

[Faceman2000]

1 hour ago, RjY said:

The only visible instance of GRAYTALL in the whole of doom2.wad.

Fascinating! I’m surprised they missed that one when they were cutting the barely used Doom 1 textures. The early version of Doom 2 Romero shared had GRAYDANG, BROWNWEL, and COMPTILE (and maybe some of the Doom 1-exclusive TEKWALLS?) all used once but they were cut before release in what I assume was an attempt to reduce the file size.

[zokum]

On 4/23/2022 at 6:34 AM, Lippeth said:

I just found out that monsters go back to their idle state when loading a game that was saved out of their sight line. I can't believe I never noticed that.

If I'm not mistaken, monsters have their current target as a memory pointer to another object, like a player or monster. When saved to disk, all these fields are set to null as these pointers would not be valid when loading a game as the memory locations would be different.

 

Save scumming in Doom makes the game a lot easier because of this effect and it is probably one of the most gameplay affecting logic bugs in the original game.

[Graf Zahl]

49 minutes ago, zokum said:

Save scumming in Doom makes the game a lot easier because of this effect and it is probably one of the most gameplay affecting logic bugs in the original game.

 

Oh yes. I remember how much I abused that thing back in the day.

 

It seems that people back then had difficulty saving a pointer. Blood has a similar issue with its AI states - and to compensate the game partially reinitializes all its actors which can screw up the entire save.

And Shadow Warrior went totally wild with it - they included a compiler's map file in their game data and used that to look up what data or function something pointed to. That was really fun for making the feature work with source ports...

 

 

 

[Gez]

Multiplayer was implemented very early in Doom's development, but of course it wasn't fully functional right away.

InsanityBringer said:

It kinda sucks since the alphas don't actually unlink a moving object from their old sector and relink them to the new sector when they cross sector bounds, so the moment a player leaves their spawn sector, they become invisible. Oh well, I just wanted to know how much worked at all.

From here.

[Scypek2]

On 4/24/2022 at 9:29 AM, peach freak said:

 

They do go back to being idle, but I believe the saved game will remember whether or not the monsters had been idle at the time of your saved game, so any monsters that were active (either they saw you, heard your gunfire, etc) will re-awaken on your first shot after loading a saved game, even if there are sound-blocking measures between you and some of the monsters.

 

The monsters reawakening is a result of how sound propagation works. Once gunfire reaches a sector, it becomes "a sector in which monsters wake up to chase you" forever. Since monsters don't normally enter new sectors without already having been alerted, there aren't really downsides to this, and it helps the monsters stay active after saving and loading a game, too. The monster pointers still get messed up in all kinds of ways, and ambushing monsters are one notable example - just like shooting in the first place, reloading won't make them chase you as normal, they'll just stand around with a 360 degree field of view until you're in their line of sight.

[Gibbon]

I usually play with darker settings to mimic a crt.  Earlier I played with the gamma bumped up and noticed another drop down chute on Doom 2 map 2 that takes you into the blue key room.  I had no idea and thought there was just that one drop down place….

 

man oh man…

[Gez]

20 hours ago, Scypek2 said:

Since monsters don't normally enter new sectors without already having been alerted, there aren't really downsides to this

That was true until ports invented ways to do just that (spawning monsters via scripts, or teleporting them from a conveyor belt). And note that monster spawning is not necessarily dynamic, Void for example used scripts to spawn monsters that it couldn't, back then (in the time before DECORATE), place directly on the map.

[Scypek2]

Yeah, I could've specified vanilla. Zdoom plays by its own rules in a multitude of ways, anyway. I think even the "shooting in a sector changes it forever" rule can be customized in zdoom now, though I don't remember if it's a compatibility flag or something for the modder to change.

 

8 hours ago, Gibbon said:

I usually play with darker settings to mimic a crt.  Earlier I played with the gamma bumped up and noticed another drop down chute on Doom 2 map 2 that takes you into the blue key room.  I had no idea and thought there was just that one drop down place….

 

man oh man…

 

Wow. That's an interesting omission. Come to think about it, I don't remember the last time I jumped down that leftmost hole.

 

I wonder what's the most obvious Doom thing I missed for a long time... Maybe it's the fact that the arrangement of the teleporters in Doom 2's MAP19's secret hub correspond to their destinations - the northeastern teleporter takes you to the northeastern corner of the citadel, and so on. I also couldn't figure out the yellow key at all and instead completed the map by going to the teleporter hub and trying to guess which teleporter will take me to the blue skull. That may not be THE most obvious thing, but still kinda silly.

Edited April 26, 2022 by Scypek2

[Revenant100]

Most shareware versions of Doom come with a README.EXE which is essentially a digital version of the game's physical manual, the text of both being nearly identical. However, there's one interesting change: In the enemies section, in lieu of being able to provide illustrations of the monsters, this digital manual provides brief text visual descriptions that haven't appeared elsewhere.

 

Here's the complete list:

• Former Humans (dudes in filth-covered combat suits)

• Former Human Sergeants (dudes in black armor, also filthy)

• Imps (brown thorny hominids)

• Demons (pink horrors, vaguely humanoid)

• Spectres (vague, half-formed shapes)

• Lost Souls (flying skulls)

• Cacodemons (gigantic floating one-eyed heads)

• Barons of Hell (you'll know 'em when you see 'em)

Important information to take away from here:

• Zombiemen and Shotgun Guys are canonically filthy.
• Imps are canonically hominids, a far cry from the insect-like depictions in later games.
• Demons are canonically pink, which is obvious, but here's the explicit confirmation if you've ever needed a citation from an official source. This also means Barons are unquestionably pink as well.
• Spectres are canonically indistinct forms. Despite the emphasis on visual descriptions here, there's no comparison made to the Demon.
• Cacodemons are canonically considered heads.
• Although we already knew this from the actual descriptions, here's further reinforcement that Lost Souls fly while Cacodemons float. An important distinction to keep in mind!

 

[BGreener]

Autorun is possible in vanilla by setting the “joyb_speed” to 29 in the config file. I would’ve loved to have learned that forever ago.

[Sneezy McGlassFace]

On 4/23/2022 at 6:34 AM, Lippeth said:

I just found out that monsters go back to their idle state when loading a game that was saved out of their sight line. I can't believe I never noticed that.

I thought only chocolate still does that, and the other ports addressed that

[Lippeth]

51 minutes ago, HrnekBezucha said:

I thought only chocolate still does that, and the other ports addressed that

I was referring to vanilla Doom and didn't think to mention it because I thought it was a given based on the context. I usually don't save for fear of "vanilla" compatible wads making me go deaf from save game buffer overflow, and don't save when playing the original game because the maps are short enough that I don't mind replaying if I die. Of course none of this is applicable in most ports.

[Sylvester]

On 3/20/2022 at 5:57 PM, ImproversGaming said:

Not sure if this was mentioned but I remember finding out that WAD stands for "Where's All the Data".

I remember it vividly as it was only five minutes ago.

I have l known that WAD stands for „Where‘s All the Data“ since like forever but since I‘m not a native English speaker I never knew that „wad“ is a word in and of itself until a few days ago (like in „a wad of tobacco“). Now id‘s choice to name a WAD‘s components „lumps“ makes more sense as well.

[Impeller]

On 4/20/2022 at 10:51 AM, Optimus said:

I noticed all UAC cylinders in this area (and also in a previous room)...

Not really something you wouldn't have noticed but I always liked the idea that those are the Spawning Vats as the map's name says. They seem like they'd house some kind of mechanically engineered demon that hell has been working on. Also, that texture SHAWN1 is a mess in Doom 1. There's part of STONE on the edge, making it impossible to use along a wall. It was sloppily "fixed" in Doom 2 and still isn't very usable.

[ludicrous_peridot]

That you could put secret exits in plain sight in Doom 2 to have a vanilla-compatible megawad spanning 32 maps and not 30 even though with a weird progression... well, if scrapping "proper secret map" was acceptable for your megawad, of course.

[Rampy470]

I was yesterday years old when I found out that it's "degreelessness" mode and not "degresslessness".

 

Don't ask me what a degresslessness is I have no fucking clue.

[MrGigglefingers]

On 5/9/2022 at 4:17 PM, Revenant100 said:

Imps are canonically hominids, a far cry from the insect-like depictions in later games.

 

I always pictured them like spiky bigfoots covered in brown fur so this pleases me. Maybe it was the vaguely cro magnon-y heads they have.

[printz]

Holy shit, I just found out that damaging floors act when your weapon bobs to each extreme side! I learned about it from a YouTube comment here: https://www.youtube.com/watch?v=ltFw-PgbtiY&lc=UgzuZ7z67NkIdCWPc3R4AaABAg.9bIJV8oXNF29bIO8GcAOb_ and I checked it live, it confirmed! So there's a way to time your runs over damaging floors to minimize damage!

 

[Gez]

35 minutes ago, printz said:

Holy shit, I just found out that damaging floors act when your weapon bobs to each extreme side!

It's a coincidence from using the same timer and the same timing.

 

Damaging floors act every 32 tics, using a bitmask of 31 with the leveltime variable:

	if (!player->powers[pw_ironfeet])
	    if (!(leveltime&0x1f))
		P_DamageMobj (player->mo, NULL, NULL, 10);

Weapon bobbing is less straightforward:

    // bob the weapon based on movement speed
    angle = (128*leveltime)&FINEMASK;
    psp->sx = FRACUNIT + FixedMul (player->bob, finecosine[angle]);
    angle &= FINEANGLES/2-1;
    psp->sy = WEAPONTOP + FixedMul (player->bob, finesine[angle]);

#define FINEANGLES		8192
#define FINEMASK		(FINEANGLES-1)

So with FINEMASK we have a cycle that loops back every 8192 "units". But this unit is obtained by multiplying leveltime by 128. 8192 / 128 = 64. So we complete a bob cycle every 64 tics. During that cycle, it goes from one side to the other then back, meaning that it is at the apex of either side every 32 tics.