airblast det flare = super jump. why?

[@SpectraPhoenix]

“This creates a memory leak, too bad!”

[@seronymus]

Too based*

[@NicolasA346]

This creates a compression of the whole universe on itself. *TOO BAD!*

[@HazmatPyro]

//USE AN EPSILON DAMMIT!

[@whoisanarnb]

@@HazmatPyro //FUCK NO

[@caav56]

"Actually, we need two memory leaks, or we lose the default string."

[@flamingscar5263]

Now this raises the question How many reflected detonator flares does it take to crash TF2 by overflowing the memory

[@TinyDeskEngineer]

Probably more than enough to crash the server because of the edict being full before then

[@ok-tr1nw]

How many flares to sprunk tf2?

[@bagelmaster2]

I have no idea how it would work under the hood, nor am I a comp sci major, so anyone correct me if I'm wrong. If the flare ID were to take up something like a single byte of server memory, the total amount of flares needed to crash the server from a memory leak would be how ever many bytes of RAM the server had left to do whatever with. If the server had 2 gigs of RAM free to do whatever it needed, it'd you'd need to reflect something like 2 billion flares to crash it. That's my guess, anyway.

[@TheFrenchmanBehindYou]

396. I checked

[@Moddingear]

it probably can't, most arrays are dynamic so they don't have a fixed size, but the number of ids is limited, so you'd have more than once the same I'd, removing itself from the list

[@ckay11002]

Now I want a team co-op puzzle map based on this """mechanic"""

[@user-un2pf4ht9l]

There is a jump map for this wep but only the normal jumps

[@paille-boy]

a coop jump map for tf2?

[@ajdude9]

That's genius.

[@christianroot6287]

it makes a memory leak

[@alex.g7317]

@@christianroot6287 k

[@jonsku6662]

Pyro vs Pyro normally: Use shotgun to kill the opponent Pyro vs Airblasting Pyro: Use detonator as a "get away from me" tool and send them to a different map

[@irregularassassin6380]

"You've activated my trap flare!"

[@jakubpociecha8819]

Send them to Brazil

[@thomaswang2223]

But the air blaster has to aim down

[@rickydo6572]

@@jakubpociecha8819 They'll cap the point

[@EquinoxWasTaken]

Pyro Vs Pyro normally: Use Flamethrower to kill the opponent

[@purplehaze2358]

This is probably the first time the words “memory” and “leak” have been used in the context of TF2 without being in reference to something downright disastrous.

[@leaderboard354]

in programming, memory leaks are almost always disastrous. A memory leak in your computer's kernel will easily brick your entire system, this is just an extremely minor leak that gets resolved by the flare hitting a surface

[@aSmallGreenDot]

Unless you're talking about the unusual effect :)

[@Nirual86]

@@leaderboard354 it depends, its very hard to avoid any kind of memory leak. Just usually its minor enough that won't affect the average user before they stop using a given program or restart the device, or some other measure kicks in that properly cleans up the memory rather than waiting for specific instructions. Its part of why server maintenance cycles exist (and why everyone should restart their devices once in a while). Of course, your example is one of the most dangerous ones considering how fundamental it is. Memory leaks in games or other programs usually just tank the performance or cause a crash, but they can't affect parts of the RAM that's reserved for the OS (unless you really mess with those settings).

[@kormannn1]

@@leaderboard354 memory leak turns my GUI into powepoint presentation, without anything able to open or interact with?

[@Nirual86]

@@lucaswenzel1765 I wouldn't say they lied, its more just lacking nuance. Programmers should definitely try their best to avoid memory leaks in their coding.

[@jackw536]

Huge props for always making everything so easy to follow with the detailed graphics and breakdowns

[@uhhhhhhidkkkkskamsksk]

Yeah it reminds me of some programs that allow you to make code with "blocks"

[@vivelespatat2670]

@@uhhhhhhidkkkkskamsksk Scratch ?

[@uhhhhhhidkkkkskamsksk]

@@vivelespatat2670 yep

[@jonathanhoward1499]

Its not that good. Just an explanation

[@-YELDAH]

i don't think people appreciate the outro gaben enough, every time it breaks my legs off

[@ethangoldd]

sometimes it really strangles me until i die

[@ThatNerdGuy0]

oh wow.... *super* jump

[@icedlemongamer]

you.. ok?

[@-YELDAH]

@@icedlemongamer no, I bled out a few hours ago

[@-YELDAH]

@@ThatNerdGuy0 ayy you got the pun in breakleg time

[@crazydog2174]

0:12 the deatail on that reload animation its actually good

[@engi3583]

The fact that source can be this weird is amazing

[@macrro]

It's like discovering a new country full of oil

[@seronymus]

Would you like some code with that spaghetti?

[@whoisanarnb]

First time?

[@KnightMinson]

@@macrro excuse me did someone just say OIL

[@LividImp]

Welcome to the mind of the Gen X programmer.

[@AzzieEquinox]

I genuinely wouldn't mind if this stayed in the game. It's really fun to use the detonator stomping exploit along with this to drop from the sky and essentially market garden people. I've played many hours of Pyro only doing that on Hightower alone.

[@champagnesupernova1839]

@@ColourlessGreen-b5z "alone" in this case referring to the map selection, Hightower.

[@oktayyildirim2911]

@@ColourlessGreen-b5z Just to let you know, the past tense of shoot is "shot".

[@alex.g7317]

@@oktayyildirim2911 shotted

[@puddin555]

you take around 170 self damage from this glitch, so even if you survive the initial damage you will still die to fall damage

[@AzzieEquinox]

@@puddin555 I haven't been able to watch the video yet, since I'm working, so I'm not sure if he mentioned this, but this also works with pipes. That allows you to control the jump a lot easier and while having an opportunity to take less damage.

[@itchylol742]

2000 hours and I didn't even know this bug existed. I hope they never fix it

[@Kerrmunism]

hi

[@kommentier9884]

Theres a very high chance they won't

[@seronymus]

@@kommentier9884 it took 8 years to fix the iron bomber projectile

[@engi3583]

​@@kommentier9884 Maybe this will be fixed in the source 2?

[@Coxick]

the weird tf2 contractor who is working on tf2 for some reason, is probably fixing it right now

[@Mic.vencer]

I love how you personify the code and mechanics of the game, it makes it very simple to understand, great work man

[@shizamikaze]

im not a programmer but i find the production of your videos really great, is easy to understand what is happening with the visuals. :3

[@tameimpalafan17]

Thank you for explaining the team fort game 2nd once again mr shounic

[@QuazzleTheQaz]

Does the penalty for self-damage ("+50% damage to self") go away when this bug happens, or does it stay intact despite the ownership change?

[@koth_harvest_final]

given that the flare's owner changes i would imagine it still counts as self-damage

[@kerbonaut2059]

No you get hit with a different bug entirely and take 170 damage instead. Thanks Source!

[@VanessaMagick]

Because the Flamethrower has an internal 'damage' number that doesn't actually matter one bit for flame damage. Airblasted explosives and whatnot do much higher damage than they're supposed to because its reading the Flamethrower's base damage, not the launcher.

[@kerbonaut2059]

@@dkskcjfjswwwwwws413 any reflected projectile that adds to killstreaks - aka everything except rockets.

[@no.nomoreidontcare]

Wrong, they deal higher damage because of minicrits on reflect, and it's an intended feature.

[@pastalavista5784]

I think my favorite part of these videos isnt even learning about the specific tf2 related things and more learning about all the systems that multiplayer games have that make sure that every little thing is accounted for. Makes all the technical issues seem a lot more reasonable.

[@Lemon_Inspector]

I'd like to think this TF2 is an abnormally bad example of multiplayer game programming, but, well... everything I know about programmers says that's probably not true.

[@amberglass7397]

tf2 is actually surprisingly stable and well made for a multiplayer game of it's age that has kept getting updated. minecraft is another example. bugs like this will arise in any game, the reason they stick around is because tf2's issues are due to a lack of people actively maintaining it (which may not be the case anymore, given recent bugfix updates)

[@Nirual86]

@@Lemon_Inspector it is running on a pretty old engine and all the additions over the years only made things more complicated. The lag compensation system for one didn't really age well, and the melee hit registration system clearly wasn't designed with Demoknight, medieval mode etc in mind.

[@NickYea]

I love these videos, they are always so informative! Thanks as always shounic!

[@shounic]

:)

[@JoeyCheerio]

thank you shounic, this FINALLY answers my question!

[@Rob77niner]

well obviously, the airblast simulates the malicious railcannon and the detonator simulates the core eject grenade

[@joltenx1014]

yes.

[@RisenSlash]

machine

[@Unluckydood]

This was one of the first videos I watched that introduced me to tf2, (besides meet the team videos and sfm) and it’s one of the most high quality videos I’ve seen on tf2

[@MarkRosOfft]

yeah this guy makes cool design videos

[@ytgumby]

your clean illustration of this confusing dilemma makes it easy and funny to understand and I appreciate that

[@wgkgarrett]

The craziest thing is that I learned a niche pyro bug from someone other than Sketchek

[@kritz9997]

Where were you in my life when I was assigned to make a breakdown video for my group project back in highschool, this is so detailed and easy to follow!

[@lilithFGC]

The visuals are so helpful for understanding what’s going on! It makes all this source spaghetti make sense!

[@diegodankquixote-wry3242]

This is pog level infinite. Now almost every jump map can be beaten by pyro now. Unfortunately not on any normal jump server so any pyro only players will forever be unranked :(

[@isylvia]

i need this guy to analyze the code in my games to figure out the bugs

[@polyhex]

oh perfect timing, i just got done watching half of your channel again for the 3rd time

[@JustFrameParry]

Wait, does the superjump only happen if the original pyro tried to detonate the flare or regardless of that?

[@lanfour4444]

If I understood correctly after it gets reflected the original owner can't detonate it anymore.

[@OmegaRC59]

@@lanfour4444 no, the original owner can detonate it but it gets deleted shortly after that's attempted. So you can input multiple explosions within that time frame because the flare was never removed from the list of active flares from the original shooter

[@spad_overolls]

@@lanfour4444 the original owner can detonate it more than once due to the flare failing to remove itself from the original owner's list upon detonation (the flare will be deleted from the game world during the engine's next deletion check since the first detonation, but the flare's id will remain in original owner's list because the flare failed to remove itself from that list) tl;dr: after being reflected, flare and original owner have one-sided communication where original owner can communicate to flare, but flare cant communicate to original owner

[@StackMan]

It might be that, when the flare hits the ground, it will explode multiple times, but it's not clear.

[@rayhatesu]

My understanding given the language Shounic used is as follows: 1)The flare tries to remove itself from the list but can't. 2)The flare attempts to delete itself, which is the actual "damage calculation" happening. 3)Because of the issue with step 1, step 2 repeats as often as it can within the detection window, likely leading to between 2-3(just going by the visual indicator) detonations worth of damage and knockback being generated in this instance. Were this window of time extended slightly such that further signals could be sent through the server, say during a server hiccup, this multiplication could likely become strong enough to kill the pyro outright, if not send them on a trip reminiscent of using a Detonator for jumping while on a x10 server.

[@banananana2]

Can you do a video on what happens when certain situations happen simultaneously? Like if you shoot the same frame you get kritz from a medic or other another weapon that get kritz such as the diamondback or frontier justice. Or if you get hit the same frame you activate bonk or get ubered. Shooting the same frame you die? I'm just interested in which outcome takes priority.

[@lanfour4444]

He already has video on that. In summary when things happen at the same frame they usually prioritize who joined the server first, sometimes who joined last but also can be random, there's no telling until you test a specific condition.

[@banananana2]

@@lanfour4444 Wasn't that video about capturing objectives? The situation I described is different

[@TheFlynCow]

@@banananana2 it depends on each players userid

[@leaderboard354]

@@banananana2 it was, but the distinction isn't important. the server will always go to join time, ping, or uid to decide what to do first in any situation. source isnt THAT terrible.

[@Nirual86]

@@banananana2 he also did one on kills (who gets credited, who lives if two people tauntkill eachother at the same time etc). Same system applies.

[@unscblackbeltgi5893]

I've only recently discovered your channel but your explanations of game mechanics and the underlying algorithms are concise, to the point, well-illustrated and make perfect sense. I'm glad KZbin decided you'd be a channel I'm interested in because I certainly agree.

[@The_D_ray]

I just love to see videos on how messed up codes can be in this game. I'm not joking, is really interesting and entertaining.

[@SioxerNikita]

I find it interesting that the detonator don't just "detonate all" followed by emptying list. Seems weird that it wants the go ahead from the projectile

[@TheCrappyCompletionist]

Wow. Interesting to see these kinds of functional videos where broken mechanics are explained. Keep it up!

[@Flynn217something]

I cant wait for the TFtuber video "Detonating a server with reflects"

[@ThePlayerOfGames]

Excellent presentation! A visual treat overlaid a fine technical explanation!

[@FrappuccinoAlfredo]

I love that I keep learning new things about the game 15 years after launch

[@johannalbanschopfer5856]

Dude, you are amazing at visualizing programming concepts. You should create educational material for a living!

[@pyropyropyro8549]

watching these videos is always worth it for those gabe quotes at the end

[@valdericecosta3636]

This channel feels like Marblr but covering the superior game

[@Engineer12798]

Does every flare have a unique ID? Would it be possible for someone else to fire another flare with the same ID, and then you detonate it through the stale ID? What about for other projectiles, objects, or even players?

[@leaf5216]

yes everything has unqiue IDs, thats the entire point of IDs. identification.

[@DanielLenrd]

detonator sends a request to player "Detonate Yourself"

[@GGreenHeart]

@@leaf5216 IDs are often only unique within a certain scope. Each particle in a visual effect has a unique ID, but they're unique to the vfx- they might overlap with, say, the IDs of voice lines for the heavy. If the ID context for the flare is, say, all Detonatables fired by that player, then it's possible that the ID of another player's flare could match with the ID of something *You* fired.

[@leaderboard354]

the whole point of an ID is for it to be different than other IDs lmao. what is this question in your very strange hypothetical, though, for you to detonate a flare, YOU have to be the owner of the flare. the flare could still share the same ID but it would not be tied to you, so no.

[@Lemon_Inspector]

Stupid "by definition" arguments aside, the "handle" used seems to be a combination of an index in a global list of entities and a serial number. So the new flare would have to both end up at the same slot in the list *and* be exactly the 1048576th object created after the first flare to convince the game that it's the same object.

[@playday663]

Literally Ultrakill

[@TinyDeskEngineer]

The detonator feels like the kind of weapon that would only allow one projectile to be shot out at a time.

[@sqilluy]

"oh wow, super jump" -GabeN the quotes at the end are always so funny. idk why.

[@sooperdude22]

Soldier: "Screaming Eagles!" Pyro: "Mmph huh huh!" Translation: _"Hold my Phlog."_

[@Bifstak]

I'm going to use your style as inspiration for my presentations at work now.

[@lorenzodepaoli3642]

just to show how good the editing is, I fully understood the video even without volume

[@Hobobatman1000]

Too bad you'll never see this in game since every pyro uses the scorch shot instead

[@moosedog___6372]

Bro the detonator is so fun I really wish it wasn’t overshadowed by the scorch shit. Doesn’t mean I’m gonna stop using it to get into weird places or chase people down.

[@K_NERVe]

"It just jumps" - Todd Gaben (1908, colourised, probably)

[@uhh12131]

We have got to push this gimmick to the limit!

[@Yeast3]

I feel like this man knows everything, he makes me feel like shit. Not like I had brain cells in the first place.

[@iminumst7827]

You know what would be super cool? If Pyro could reflect his own flares. Imaging shooting any flaregun straight up into the air then reflecting it forward after it comes back down, would be stylish as heck. And it would actually be useful if they made his detonator and scorch shot jumps amplified if reflected.

[@Dazllingston]

1) Too niche 2) Too broken with right angles

[@caav56]

Sounds like Projectile Boost in Ultrakill.

[@scutula]

+PBOOST

[@kapsaysin]

Never even knew this existed. That's really cool tbh.

[@ryankhorwell]

Flying with the Axtinguisher is now taken to another level thanks to this Because just IMAGINE someone airblasting Detonator flare, surviving this multiple damage, somehow setting enemy on fire and then hitting him with the Axtinguisher. That would be crazy as hell

[@johncronk8867]

If there’s a way to replicate this solo, Pyro will suddenly join Soldier, Demoman, and Demoknight in the “Aerial Superiority and Superspeed” club.

[@puddin555]

you would need the survive the initial 170 damage and then survive fall damage

[@no.nomoreidontcare]

If you do this mid air (like before landing) then its alright

[@Davtwan]

Hearing Gaben say “super jump” made my day. (Also hooray for Pyro shenanigans.)

[@angrypicture6155]

Idk how many people tell you this, but the gabe bits at the end are hilarious!

[@DeuxisWasTaken]

"the spaghetti zone" lol, I love your descriptions

[@tulsatrash]

As soon as I read the title I clicked because I wanted to know the answer. Thank you for giving me the answer.

[@sqbuilder1328]

"This causes a memory leak...." Too bad!

[@lawrencebermudez]

1:54 Very interesting, would you happen to have a metaphoric visual representation to explain how the game checks for detonated flares every 0.015 seconds?

[@EnigmacTheFirst]

Framerule moment?

[@DrMonty-ng5fo]

The 0.015 seconds is referring to how the game runs at 60 frames a second. One frame = 0.015 seconds. Think about it like this: if the game had to calculate literally everything every 0.001 seconds, no computer would have the processing power to run it. So, the vast, vast majority of video games instead calculate everything every 1/60th of a second. So basically, the bug in the video is caused by someone being able to input detonations faster than 1/60th of a second, which is too fast for the game to check each one, causing it to explode multiple times. Does that make sense?

[@poopman8624]

@@DrMonty-ng5fo I think he was making a joke referencing framerules in Super Mario Bros. There's certain things (such as finishing a level) that the game only checks every framerule (21 frames), so time can usually only be saved in increments of one framerule. In the speedrunning community bus schedules are often used as a metaphor to explain how framerules work, so much so that it's become a meme that every time someone mentions framerules, they go through the entire bus schedule metaphor.

[@Spartan_Tanner]

1:42 NGL that looks sick

[@Thegentechgamer]

shounic + marblr = legend

[@wilma_wessels]

I remember seeing a guy do that in a pub match. nice to know how it happened after all this time.

[@SodogeWow1337]

Hey Shounic, do you know that weird glitch (mainly on 2fort), where when you kill someone there is a chance their model that plays the death animation will teleport to the middle of the bridge and then disappear? Do you think you could explain it?

[@Winasaurus]

I can just imagine new bots bullying noob pyro players by constantly airblasting their flares, slowly lagging him out as his detonator holds thousands of uncleared flare IDs, and he has no idea why.

[@JoeyGames123]

I never realized that the detonator projectile was a fire work

[@KenonArtulii]

Huh, I had thought this was due to the damage value of the flamethrower being used like reflected pipes. It's interesting to see it be caused by multiple detonations instead.

[@Vinci480]

"Oh wOw Super JUmp" - Gaben, 23.08.22

[@yazidefirenze]

"Oh wow, Super Jump." - GabeN

[@redstonewarrior0152]

I want to see delfy doing some really stupid crap with the infinite detonation crap. That seems fun

[@chilchuck.]

oh yeah it all coming together

[@Guruc13]

My eyebrows shot up high as that jump!

[@orly4672]

I'm smelling a new Octo gimmick video

[@dyscolored]

bro explaining why a super jump works like he doing a powerpoint presentation in class 💀💀

[@bunnyonabunwithagunnicepun5689]

The OG pyro movement tech

[@zstepp6]

Surprisingly great edits wtf

[@blamedrop]

Cool gimick. But I don't really see a good explanation in this video. 1) What do you mean by "when an air-blasted flare gets detonated" by who or what? By collision I guess? Doesn't collision (or detonation which can't work after deflecting?) work so it spawns explosion and deletes itself? 2) Why it gets deleted eventually? Why it doesn't leave a point of never-ending explosions? 3) By what (and how many of) you got pushed away? 4) Ad. this memory leak doesn't it last only until player respawn? 5) And what exactly were pyros doing at 2:33 demonstration?

[@zmaxx123321]

1) The airblasted flare is still in the original detonators list, so the shooter can actually still detonate it with mouse 2 2) When a flares gets detonated it doesn't erase the projectile, it flags it for deletion that the source engine checks every 0.015 Secs, allowing for a reflected detonator flare explossion to occur every game tick between that time, if the original owner keeps detonating it 3) probably 2 or 3 times 4) Probably the list gets destroyed if the player changes class or dies, however it still a potential crash if the detonator player stays alive and gets their flares reflected for a ludicrous amount of time 5) They were testing point 2

[@mrdumpfree8216]

It’s crazy that all this happens in just a second

[@-NGC-6302-]

Outstanding video quality

[@ilmakopad]

As if a flying Demoman weren't scary enough...

[@notanimposter]

"oh, wow, super, jump" Best GabeN quote yet

[@WilliametcCook]

I wish my programming bugs had videos this detailed about them

[@Nikkidafox]

So here's a question. What would happen if the pyro airblasting did have a detonator and currently had a flare active when airblasting?

[@Emma-rw8yo]

He says it doesn't work if the IDs don't match. Given that the IDs are 32 bit numbers, the chance of there being two flares existing at the same time with the same ID is effectively zero (if there isn't something specifically built in to prevent the IDs from overlapping. He used "1" as an example ID because writing an actual example of an ID would be needlessly long and not necessary for the point the video is making

[@GiRR007]

even the GAME knows the detonator needs to be buffed.

[@entothechesnautknight1762]

I kinda hope this bug stays like the civilian bug is. They've been patching bugs left and right lately, but the fact that bug is still here tells me they don't wanna patch *every* bug, just the ones that actually are problematic. Hopefully this tiny memory leak doesn't become a problem. (Also, I think this was a pretty good visualization of what a memory leak is. Like, I knew what the concept was, but just seeing it laid out so plainly really helped me understand the concept better then any in depth explanation I've seen )

[@vert3432]

The memory leak could be fixed without fixing the superjump, just add a function to clear the active flare list upon death and/or match end

[@frostnovaomega1152]

i was super sure this was gonna be the same deal as the direct hit airblast bug, but turns out the source spaghetti never fails to deliver on unique jank

[@Raz-G]

I thought because the airblast converts team colours, it doubles it's value by adding another owner (the one who airblasted) and so since it's not deleting itself, again it creates two of the same shells into a physical value of one. But yours seems like a better explanation...

[@e2b265]

Shounic doesn’t make these videos for us, he makes it for the TF2 devs to understand what they just programmed.

[@saihtama]

Your animations are really good fren

[@andyfriederichsen]

0:00 I have never seen a Detonator jump that high before.

[@Minty_Meeo]

So basically, it should be using the detonation control value instead of the projectile owner value to callback to the flare gun. Combine that with the instant-deletion hiding most of the symptoms, and I can see how this bug would slip in unnoticed.

[@blazernitrox6329]

If the flare marks itself for deletion, but the engine only GCs every ~1/60 seconds, would that not technically be a deferred deletion? Or is this some weirdness where that IS "immediate", and Source also has a separate deferred deletion? Also, shouldn't this be a problem with airblasted stickies as well?

[@JohnPaulBuce]

oh wow, super, jump

[@Vexcenot]

This has happened to me before but I never found it weird since it was tf2 and basically felt as normal as breathing

[@ActuallyRocatex]

JOEY CHEERIO FIRST PYRO INTO SPACE LETS GO

[@rodneybuckentime4838]

guessing before he explains, so I may be wrong: reflected projectiles do 3x damage because they become crit-boosted, meaning that the knockback of it is tripled.

[@seronymus]

After 9 years in development....

[@SimulacrumF]

i wish this happened when i reflect detonator flares, instead i just die because of the massive self damage it does specifically on airblast, once it did at least 152 damage

[@sgas]

wow, what an interesting but, I had no idea

[@simplysmiley4670]

Source Spaghetti at it's finest

[@comicallylargerat7896]

I feel like an interesting fix to this would just be to turn the flare into a regular flare. Though I imagine the scourge spaghetti would not be good