Oh the memories of doing Eternal DOOM (not to be confused with DOOM Eternal) co-op run in 90s LAN parties. The amount of times the sentence 'oh, it was you? sorry' was uttered...
I love that Doom has this surprisingly in depth implementation for its fuzziness effect, then its RNG table is just 255 random values with no real logic or weighting to it. What a fascinating game
Shaders weren't a thing back then (because graphics cards weren't a thing). I played Doom on a 386 (under 40 MHz) for example. That CPU had to do EVERYTHING -- not just collision, player input, and enemy AI but rendering. They simply couldn't do complicated algorithms to mimic shaders outside of table lookups. It is impressive that they accomplished what they did.
There IS a weighting to the RNG table! It's a rough bell curve with a slight bias towards the high end. Decino has shown plots of it in previous videos.
Important to note for GZDoom types: You may notice enemies do NOT spot you by default. However, in vanilla, enemies will still spot you through the power-up. Heretic's Shadowsphere DOES have the GZDoom style mechanic in its vanilla game though!
Honestly always liked the enemies not spotting you with partial invisibility. I began playing on Gzdoom and was disappointed when i moved to other sourceports that didn't have that
Funnily enough, one of the recent GZDoom versions (4.12, but seems to be fixed now) somehow broke angle randomization completely. So you would have enemies attacking you as if you didn't have it.
Also important to note pretty much the whole ZDoom family of ports has this, including ports like Zandronum. The change in behaviour came when ZDoom got Heretic support, because the code for that behaviour from the Shadowsphere was intentionally added to Doom's Blursphere. The early days of advanced Doom ports was a wild west of changing the game's behaviour, keeping the vanilla game as is in more advanced ports largely started with PrBoom and its descendants, with their features like complevels.
If you play around with it in GZDoom you'll notice that sometimes the enemies notice you anyway. They have a random chance of spotting you if you get too close or move too fast, so keep your distance and move slowly (slower than walking speed) and you'll remain hidden for as long as the powerup lasts. This is also taken from Heretic's Shadowsphere.
Fun lore fact Spectres are pinkies with a cacodemon eye put inside of them giving them psionic abilities in doom 2016, if we apply this logic to the classics then the invisibility sphere is a cacodemon eye.
Processing... Initializing... New headcanon accepted. Error... Cursed thoughts detected. Are we just chomping down on that powerup, or do we just crush it in our hands to achieve power?
As a kid, I couldn't understand English very much, but I knew what "Invisibility" meant, so when I picked it up and the monsters still saw me, I thought the demons use thermal vision like a Predator or something. Didn't even notice how it works, because I was a stupid child and strafing was something I didn't do at all, so it should have been obvious. Yes, I struggled with the Cyberdemon, how could you tell?
Can Maulataur in Heretic be beaten on lowest difficulty skill by using arrow keys only? With Ring of Invulnerability, yes. Maybe this is why my mom liked Heretic more. You should try Heretic, it's easier than Doom I guess.
@@CsubAzUrmedve Szia Csúb! I also started with Heretic, I was like 3 years old when I played it on a Windows xp that didn't had any audio card and I played using the arrows and for slower movement I used the mouse. I love Doom and I'm also planning to make a total conversion Doom mod similar to Ashes and Hedon!
“The Revenant’s homing missile doesn’t care for your partial invisibility” has the same energy as “The missile knows where it is because it knows where it isn’t”
I'm pretty certain I've seen maps that force you to get a partial invisibility and have to run past a room full of Cybies lobbing rockets at you. Talk about evil.
I HATED the Invisibility power up. I was already good at dodging rockets 🚀 and fireballs 🔥 but with the Invisibility power up I start to zig and I get hit because I should have zaged. I end up running into projectiles. Would piss me off with a passion.
yeah I just avoid it most of the time cause its easier to just dodge predictble firing pattern. could be good in areas woth not enough room to move around, but thats it. For hitscans, its always good though.
I never really cared about the partial invisibility powerup until that one map in Plutonia where you pick it up and this huge window opens and you're surrounded by monsters, a lot of them hitscanners. I thought I was done for until the chaingunners opened fire and they missed almost all of their shots. I took the initiative and started cleaning house. That was a pretty memorable fight, and it goes to show that good item placement can really elevate a map, just as much as where a mapmaker places his enemies.
It's a pixel shader before shaders were a thing! Might be a fun little exercise to implement it in GLSL. Maybe I'll give it a shot when I get back to my computer.
Imagine how much data should operate PC while running this game. Never before thought about it, till watched this video. And it's huge work was made on dawn or game industry by people, without any ai helps and tricks.
The irony is, in most shooters a blursphere or similar item would be unambiguously good, because you had no chance of dodging all the bullets anyway. You're basically hoping the enemy misses you, so a higher chance of that is never bad. In classic doom (especially nowadays) that's only true for hitscan, or in rare cases where there's just a comical amount of enemies shooting you. It's an item that makes sense in every fps except the one it's in.
Magenta does have a significance in the works of H.P. Lovecraft that inspired Id Software (at least John Romero and Sandy Petersen), but I'm not sure if the people behind Eternal Doom were familiar with it, at least none of their map names reference any of Lovecraft's works.
The Revenant missile knows where it is at all times. It knows this because it knows where it isn't. By subtracting where it is from where it isn't, or where it isn't from where it is (whichever is greater), it obtains a difference, or deviation. The guidance subsystem uses deviations to generate corrective commands to drive the Revenant missile from a position where it is to a position where it isn't, and arriving at a position where it wasn't, it now is.
the idea of a power up that scales in power based on how *gaudy the background is* is deeply, deeply hilarious to me. like imagine if a new weapon were to get released in smth like Fortnite or Splatoon or Third Example Of Contemporary Shooter Game With Any Emphasis On PVP, where it has an ability directly correlated with how much *plaid* is in your surroundings. gotta love a weird engine quirk like that. ;P
Curiously enough, this still is an issue in modern games. As an example, some fighting games have banned some characters' alternative costumes because they would remove or hide certain visual cues.
Tournament bans also extend to stages due to visual noise or other issues - IIRC there's a Street Fighter 5 stage (a flying plane) that's banned in organized play because the swaying background can give you motion sickness.
It's hilarious how the level Dead Simple has several partial invisibility spheres but pits you against enemies whom the effects wont benefit you from. It's like even the guys at id didn't even know how they worked
Yeah, because PSX Doom didn't have a specific entity for invisible Pinkies, so technically there's no specters in PSX Doom, just Pinkies with the translucent flag on applied to the map thing directly. There was also a flag to make any entity subtractive and double their HP, that's how they made the Nightmare Specter, but you can apply that flag to any enemy. There were Nightmare Imps during development but were discarded, there's a magazine scan with a screenshot of one in E2M6, but you can easily make any Imp a Nightmare Imp by enabling the flag on one of them. Barons look pretty neat with that flag too!
An interesting exercise would be to combine hitscanner attack accuracy data with their rate of fire and get DPS numbers (given the player doesn’t break line of sight the whole time). Could be valuable for mappers who wish to provide tight and precise challenge.
That's definitely the most annoying thing when you pick up partial invisibility when you've been playing Classic DOOM for so long. You're so used to dodging projectiles and your muscle memory kicks in and you dodge right into their projectile. Also thanks for showing us the mechanics behind partial invisibility.
Just the other day I saw in a Corridor Crew video that they use yellow text in their thumbnails because it's an eye catching color. But Decino is miles ahead of them
On the Super Nintendo version of Doom, the partial invisibility power actually makes you invisible to monsters. You can walk right in front of them and as long as you’re not inches away they won’t see you. On the SNES the Partial Invisibility sphere is one of the best power-ups in the game. The SNES version had to cut some serious corners but this is one instance they actually improved on the original game.
Yeah, the SNES version was the first one I owned, then playing other formats made me wonder what was broken about the invisibility. The SNES version did have a couple of interesting aspects with the weapons - I believe the shotgun was just a single shot with a heavy damage multiplier over bullets, making it more like a long rifle, and the BFG worked differently, with a big splash like a souped up rocket launcher. Plus there was a fun bug where the backpack gave you ammo for weapons you didn't have yet and you could trick the game into giving you a single shot with "ghost" weapons by switching and pausing weapons.
The partial invisibility probably works that way on the SNES to compensate for monsters' lack of sprites that aren't front-facing. Which means it's outright impossible to ambush them.
@@NerfPlayeR135 yeah, for sure - it was a very cut down version, but given that it was on a system a lot less powerful than the other ports, it was a bit of an amazing feat to have so much available in the first place
@@BPCRevere SNES Doom was what happened when a miracle-worker has a passion project. That cartridge was so overstuffed with hard work and mad talent that it's a wonder it didn't explode.
It was quite a strange experience when I made my friend play Doom for the first time, since when he picked up a partial invisibility he said "This is quite useful for dodging!" I was so taken back I almost jumped out of my proverbial socks.
The thing is that it messes with muscle memory of seasoned players who already know the patterns and dodge instinctively, often preemptively. A new player, on the other hand, tries to avoid incoming fireballs on the fly, reacting as they appear to the new changed angle and it is easier for them since the projectile doesn't fly directly at player.
I remember reading a post in the Doomworld forums about someone "fixing" the fuzz effect so it didn't overdark already drawn pixels and it looked extremely cool.
I always found it funny once you're good at doom the shadowsphere actually hurts you because you constantly get shots leading your strafe. I really like how Brutal Doom upgraded it, so you aren't noticed from a distance until you attack.
The more you get into decino's yellow thumbnail videos the more you realize what an absolute technical marvel this game was for something in the early 1990s.
@@simonsoupshark8009 everyone knows that in 2024. But in 2001, a 8 year old me who didn't even know how to read properly had the right to be frustrated
Genuinely didn’t know about the top:bottom row pixel quirk, and I try to collect obscure facts about the renderer like that. It makes me wonder if the fuzz effect could make use of the transparency maps in Boom, or define what row of the palette to use. It’d be pretty cool to have something like a red spectre that’s slightly easier to see but still has that classic slightly janky fuzz going on.
Amazing what the DooM founding fathers did back in the day with the technology they had all cooped up in a house. No Scrum or Agile methods needed. Just a handful of talented computer nerds who believed in their project. Thanks so much for breaking it down for us, decino. These videos make me appreciate DooM and whole lurch forward that videogames did in the 90s even more.
Linguica analyzed the fuzz effect some years ago, concluding that the "stacked darkening" is a bug, and gave us a look at a "fixed" version. (DW post ID: 1335769) A while before that, he also theorized that id were trying to replicate the "warping effect" seen in 80's The Predator, and gave us a look at it too by removing the darkening from the fuzz effect altogether. (DW post ID: 1335541) I tried commenting this a few hours ago, but I guess YT keeps banishing comments with URLs, so I resorted to providing the Doomworld post IDs instead.
Finally, after all these years, I now understand what this really does. Back in the day it always felt like the powerup is broken because enemies still spot and attack you like normal. Never really noticed the weird angle changes and different projectile flight patterns.
"Okay invisibility, great for first time players, a fucking curse for veterans, because what it does is makes monsters more inaccurate and they have a harder time hitting you, so muscle memory kicks in and you dodge right into their projectiles" Civvie 11's video on The Ultimate Doom
The blursphere is one of those nuanced powerups that mappers don't seem to know how to use to its fullest extent. There are more uses than anti-hitscan protection or extra challenge in a projectile-based arena. For example, a combat puzzle where your movement is restricted so dodging projectiles is harder could benefit much from a blursphere secret before it - not as broken as an invuln but still a big help, similar to the radsuit secret in Stardate 20x6's Vehelits, that makes the last ambush a lot more manageable. Oh, there's also yet another name for this powerup: Quantum Stone. Credit to Zeppelin Armada for this one.
I really like the chill music as it sets a very good learning environment. It's interesting how much RNG is in this game and how it adds up to the complexity we're still looking at today. It's simple but very complicated once when multiple actors are involved. I guess you could say it's like Chess... but the pieces move around in real time and have to check a 10 page table of values for everything... and one of them has a super shotgun.
at first I thought the video was a joke since the audio played but the video didn't load so I just thought that was the whole joke that the video was "invisible" then I realized that no, youtube is just messing up once more
@@decino Well, at least we got one member of the family still there, the possiblity for a family reunion is still possible! Also I do got a question. I know you're very unlikely to do anything regarding DOOM 3 because, well it's doom 3 (though I did get it recently, still looking forward to playing it!) But I am curious if you're ever going to tackle the modern doom games a bit more in-depth. More specifically, if you're ever going to tackle DOOM 4. Since more leaks and stuff were found regarding it and it's made me realize just how much of DOOM 4 survived into 2016. Was just curious if that's something you plan on talking about on the channel down the road. Also loving these videos still! Seeing these quirky things like the effects the magenta room has at the end of the video, and the effect at 12:11 has been inspiring my map designs in other games! Sorry for the long comment, just a big nerd is all, lol.
@@decino Fair enough! I am admittedly more interested the horror side of doom and honestly, the art direction of DOOM 4 and 2016. Gameplay wise, I'll be equally as blunt, they're awful. But man, I do love the horror ideas they were trying to go for. Kinda wish eternal went in that direction in all honesty with it's art. To me it's a side of DOOM that's getting more lost as time goes on, which is ashame. Because now we really have the tech to do that kind of art direction justice.
Wowowow, it never ceases to amaze me how many details I didn't know, despite thousands of hours playing and hundreds of hours in the code. Love this series. ❤ I especially liked your explanation of the color map, and the funky exploits you can use for evil level design, as if randomized offsets wasn't interesting enough. Very well done.
The engine internally runs at 35 fps, but not all of them may be drawn on screen. 15-20 fps were typically what you get from the hardware of that time.
Fun facts: 1) The easiest way to see the fuzz effect "freezing" is to have partial invisibility, pull out the shotgun, and then decrease the screen size by 1 (so the green border is surrounding the screen). This only applies to the original 320x200 resolution. 2) Heretic's translucency effect incorrectly cuts itself off at the top/bottom of the screen despite not needing to because those lines were erroneously left in as a leftover from the fuzz effect.
This is fascinating. Doom truly was inovative for its time, and still manages to amaze even more than 20 years later. That's why it is my favorite game franchise ever.
I wondered about some stuff about partial invisibility. Like why Demons face different directions from where they shoot. But this also does make me wonder something else. If you were to set the angle offsets of the demons face target angle to be the ones used for projectiles, instead of another random angle offset for the projectiles, if that'd have made the Partial Invisibility much more useful against projectile based monsters, as it would mean you get a slightly clearer idea of where the demons about to shoot. And it doesn't fuck with muscle memory as much. I personally like that idea more then just making partial invisibility prevent demons from seeing you until you do something to alert them.
4:30 - Except in some very old versions of the vanilla engine, in which the pinkies' attack worked like hitscan, and could therefore cause infighting under the right circumstances ;)
Watching this video after recording a demo for more than an hour feels very relaxing One thing I particularly like a lot is that if you pause the game, the ONLY thing that remains animated are entities with the partial invisibility effect XD XD
The first time I played No Rest For the Living, I had issues with the chaingunners in Map 4 being rather effective snipers. That is until I found the secret partial invisibility, and suddenly they weren't such a challenge at all. I can only imagine the evil laughs that were had when placing them everywhere in Dead Simple, though.
Perfect timing, Decino! I was genuinely just playing a level where a blur-sphere was particularly detrimental in a Cyberdemon fight. (Arrival, Map04: Free Press) Maybe this video will help me git gud 🙏🏻
I had an idea to make a map where dummies pick up partial invis every so often to ensure the player is partially invisible throughout the map rendering circle strafing and other typical gameplay skills much less useful.
"After all, why else would you click on that illusive yellow thumbnail, right?" I dont know about anyone else, but i have been pavlovian conditioned to click on any Decino video with that color yellow, once i have gone at gotten my nice headphones and a bowl of popcorn. Though I am also interested in partial invisibility, so, please, go on.
Meanwhile in a private boxing ring. BMD: you got to understand you fight great but I’m a great fighter. Decino: you want to ring the bell Apollo? BMD: all right ding ding. Both throw their first punch. It’s the eye of the tiger it’s the thrill of the fight rising up to the challenge of our rival Dwars: so who won the fight? Decino: he did.
Command & Conquer has a similar but more elaborate effect on its Stealth Tanks, but, notably, they did _not_ include proper range checking, meaning it will read outside its buffer on the bottom of the screen. But given the lax memory management in DOS, this rarely gave any real issues in the game; it just showed some messy glitchy pixels and that was all. That is, until the Win95 port got re-released on Windows XP, and suddenly _everyone_ was getting these crashes, and community hackers had to figure out how to fix it in the game's bytes.
TES: Arena; Daggerfall: "It's called *_Chameleon;_* it works best when stationary." Yep, just dropped that reference; *_Illusion sorcery_* is a strange wonder indeed.
the normal invuln is already partial! you just have to get hit by something that does over 1000 damage in an instant. the only thing that can do that in vanilla doom is a telefrag
I'm always amazed by how Doom was programmed with all the little details that went on with monster behavior and many more things, just next-level for its time.
I did like in the Brutal Doom version that the invisibility sphere does make it so (most) enemies can't see you if you're quiet but that demons/spectres will still find you regardless as if they were hunting you by smell alone. It was a nice touch
The magenta part was interesting, and if it weren't for ports being able to replace the fuzzification with a different transparency method, I'd smell a WAD that _abuses_ this to be as painful as you demonstrated...
Back in the 1992-1993 when the game was developed, no one played still maturing FPS games by zooming through the maps, strafe running in circles around enemies and spamming rockets all in the same time. Most players used arrows and keyboard only for playing, turning in place and standing during shooting. Then Partial Invisibility had much more sense, as it was crafted for mostly static or not much mobile targets.
"The Revenant’s homing missile doesn’t care for your partial invisibility" Makes sense as your are partially invisible in the visible light spectrum while the homing missile would use infra-red radiation to track you.
I've been on a massive classic DOOM kick, and these mechanic explanation videos are so fascinating to me. Always wondered how that fuzz effect was done :0 Hoping for a video on the DOOM alphas someday. I remember you and Dwars asked Sandy about the dark room with a skybox in E2M7 having a ceiling, and it actually did in the alphas! A lot of skyboxes in Hall-Petersen maps were originally ceilings, actually...
Great video as always! One aspect that wasn't covered was how (if I'm not mistaken) invisibility is interpreted by sleeping enemies differently in different source ports? I remember playing certain maps/ports where monsters don't notice you until you shoot them or bump into them, even when standing right in front of them?
@@decino Makes sense. A weird deviation in "core logic" for a port to make. I remember feeling like it was more of a bug than a feature when I discovered it the first time.
It's a quirk of ZDoom family of ports. It's actually because partial invisibility in ZDoom uses code from Heretic's invisibility powerup. ZDoom got support for Heretic fairly early on, and back then making changes in behaviour like this were commonplace in advanced ports, even the Boom family used to make changes like that before PrBoom and its descendants. GZDoom has been working to undo many of these changes for a while now with compatibility options for these gameplay changes
I absolutely love this one and generally how you make the process of coding these things really easy to digest, you're really helping preserve the craft
Great video! Editing and visuals were on point, love the work you do with getting the in-game footage at various angles and with useful examples. Top quality stuff
