As a game dev, this is the level of bug-reporting quality we only dare hope for in our wildest fever dreams.

@sarunint

Ай бұрын

The reason Minecraft bug reports can be so datailed is because the Minecraft EULA allows end-user to decompile the game. So technically Minecraft is a source-available software.

@Poondaedalin

Ай бұрын

finally, something more than "the game stopped working, please fix it :("

@aladanor

Ай бұрын

I agree its great but honestly not sure how i would fix that bug, without breaking anything else or have more computation and checks.

@Khantia

Ай бұрын

@@aladanor personally I would give the same tolerance for the onGround check, as the status has, so there wouldn't be a discrepancy between the two. But yeah... I'm not familiar with the rest of the code, so I don't know if this wouldn't break something else xP

@noahblack914

Ай бұрын

​@@aladanorI mean, the system (at least as explained here) is definitely a little clunky. Probably because Minecraft is approaching 15 years old after all. I'd have to look at the actual code, but I imagine some cleaner logic for handling the fall would either eliminate this bug all together or at least make it easier to fix.

The status of neither being in the air nor on the ground is what we in more basic speech call "Swimming".

@88porpoise

Ай бұрын

And, specifically relevant to this, being in water negates all fall damage.

@Jazardly

Ай бұрын

that could also possibly be the status of being on a ladder

@llKirosll

Ай бұрын

in lava, yes. :)

@Marco-ti8sx

Ай бұрын

Or cobweb, right?

@saavyk1264

Ай бұрын

I have a feeling that a lot of things that negate or reduce fall damage would be relevant here. I'm not in the air, I am actually: in water, on a ladder, in a cobweb, in lava (it doesn't negate it then for some reason), in scaffolding, in powdered snow...

Floating point numbers causes boats to break. Makes sense, since boats need to float correctly.

@jacobhgoldman

27 күн бұрын

11/10 comment

@abebuckingham8198

27 күн бұрын

Extremely underrated comment. They should pin this. 😆

@adityakhanna113

27 күн бұрын

Gosh this is genius

@landru27

24 күн бұрын

@@abebuckingham8198 no worries; it has floated to the top

@CtrlGame

24 күн бұрын

@@landru27 just because is a good point

Another fun fact: If a boat falls from 44970 blocks high, it will not break despite it being in the sequence calculated. This is because after falling for that long, the tiny difference between 0.0399999991059303 and 0.04 compounds enough to offset the boat by more than the 0.001 block margin to have the ON_LAND status. This also means that boats are safe to fall from any height of 43543 or higher until you get all the way up to 1794944 blocks, at which point the boat is offset by the 0.04 blocks needed to wrap back around into the range where it can take damage, after falling for nearly 8 minutes.

@RobinNashVideos

20 күн бұрын

Lovely fact!

@ralanham76

18 күн бұрын

❤

@eightyfoahh

18 күн бұрын

❤

@reIONEre

16 күн бұрын

That is far more than the maximum height....

@Chase3141

16 күн бұрын

@@reIONEre yeah but you can get mods that remove the build height limit. You can also just teleport the boat to that height.

12:54 "famously, multiples of 5 are at least 5 apart"

@MCLooyverse

Ай бұрын

But only if they're distinct!

@aurelia8028

Ай бұрын

Yes we all saw the video, mate

@MCLooyverse

Ай бұрын

@@aurelia8028 Not necessarily. Every once in a while I will space out and miss a line like that. Regardless, this is a comment conveying appreciation for a good joke; it's positive feedback, and good for the algorithm. It has value, even if it has none directly for you.

@talideon

Ай бұрын

To be fair, this makes more sense when you know how floating point numbers work. It's a reference to rounding errors that crop up all the time.

@gregorymorse8423

Ай бұрын

That was profound.

9:42 The reason we need to check that fall damage was actually caused by falling is that Ender Pearls deal fall damage to the user when used.

@tetsi0815

Ай бұрын

This comment needs to be pinned! 😀

@petergerdes1094

Ай бұрын

This suggests that if you use them while in the air you would be immune to that damage because your status would be IN_AIR. Is that correct?

@modernkennnern

Ай бұрын

​@@petergerdes1094you take damage regardless 😅

@ShadowlessDeath47

Ай бұрын

​​@@petergerdes1094Ender pearls teleport the player, and I'm assuming that the position (and therefore the ON_GROUND status) happens before the damage check is done.

@ouroya

Ай бұрын

@@ShadowlessDeath47 ender pearls do not have this check, it simply deals 5.0 fall damage to the player

Him: Warning math people they don't need to know anything about Minecraft to enjoy the video Me: A Minecraft person, worried that I need to know anything about math to enjoy the video

@supsnail

21 күн бұрын

haha

@asheep7797

21 күн бұрын

This video simplified: Computers do not like numbers that are not multiples of 2^integer.

@mazaytv5664

21 күн бұрын

Oh, hello there)

@taliadx

20 күн бұрын

and DID you need to know about maths to enjoy the video?

@NiaSwift

18 күн бұрын

hi moggy swampy

imagine being the mojang dev that receives the bug report containing a full stand-up maths video

Last time I saw a gaming breakdown this specific it involved parallel universes.

@IcecalGamer

Ай бұрын

Mario?

@darkshoxx

Ай бұрын

@@IcecalGamer M(a/2)rio

@pas-giaw6055

Ай бұрын

Matpat

@ruben307

Ай бұрын

i wonder how many half a presses was needed for this.

@Spolt_main

Ай бұрын

Super Mario 64 TAS Speedrun for anyone wondering.

"whatever floats your boat"

@megamangos7408

Ай бұрын

This is such a high quality pun it hurts. +1

@Q_20

Ай бұрын

genius

@JustAnotherCommenter

Ай бұрын

+2 moment

@Owl90

Ай бұрын

You win the internet for today.

@SicTr4nsit

Ай бұрын

pff, get real

examples of both on_ground and inair being false: -climbing/descending ladders -swimming -falling through cobweb -climbing/descending vines -riding a boat/other entity 8:54

@chickenmaster3879

3 күн бұрын

Also probably sinking through powdered snow or scaffolding. Maybe sliding on the side of a honey block. And potentially gliding with an elytra because the damage taken from crashing with an elytra is calculated separately from fall damage, so there's probably a different state specifically for that.

@ejvalpey

2 күн бұрын

This makes me wonder if Matt has his explanation slightly off and it is the case that the boat’s in-air value is true but your in_air value is false when riding in the boat and usually means the boat bypasses its damage calculation except for the floating point cases and separately you bypass the damage calculation except for these floating point errors where maybe the boat has reached the ground; been destroyed; your in-air gets set to true; so in the next tic you don’t bypass the checkFallDamage method and instead die.

@redfrog9717

Күн бұрын

Actually, horses don’t count (unless it’s Bedrock version) if I recall correctly Edit: I made a mistake. This is for fall damage when riding horses.

@eugenefullstack7613

23 сағат бұрын

climbing was the first thing i thought of

Went to investigate. Turns out 198 will break the boat with a player in it (although it waits to do so until you leave the boat), but doesn't cause player damage, which is probably why it isn't in the short.

@Systox25

Ай бұрын

🙃 Minecraft physics

@jneal4154

Ай бұрын

I was trying to figure out why no one was pointing out that there was a missing value in his list... several times.

@BlueCyann

29 күн бұрын

12 and 13 also don't cause player damage, though, (and also don't break the boat when a player is in it), so I don't think that's the reason. I think people just repeat the "theoretical" values without testing them very thoroughly. Something about "player in boat" is different from other cases, for both the rider and the boat itself.

@AAFREAK

11 күн бұрын

I was thinking of that, though that was included in the bug report. The video that was documenting this though was specifically about the java edition, which I don't know if that's either significant, or that wouldn't make a difference and it was just overlooked when the short was published. Either way, the important issue is that this phenomenon was recorded through the bug report, which I'm more inclined to monitor.

@AAFREAK

11 күн бұрын

@@BlueCyann There's about 2 kinds of negligence upon the short's inclusion of 12 and 13, as it's omission of 198. However, nothing about this is theoretical. It's in the bug report, and the report does mention that there are different conditions which the player does/doesn't survive (but never specified which). They simply used examples of the affected values to illustrate the point about the bug and how that's handled. I would think that would've been beyond the point to include the player in the test used in this video when it's illustrating the fall damage to the boat with those values. When the boat is "destroyed" is a whole matter unto itself with the game's code in relation to the distance. That's already covered.

Climbing on a ladder doesnt count as in the air, while also not being on the ground

@uu8217

Ай бұрын

swimming maybe too? (if you can swim in that game)

@atemoc

Ай бұрын

@@uu8217 You can swim in the game (properly only as of only a few years ago), and it has its own state.

@JorgetePanete

Ай бұрын

doesn't*

@andrewwebb917

Ай бұрын

You can also climb vines. And scaffolding, though that may be considered on the ground. You may also be in lava or falling though a cobweb. Or lying in a bed, or riding a horse. I'm not sure what any of those mean. .

@2424Lars

Ай бұрын

@@uu8217 There's boats, so obviously you can swim

I love how we’re all just accepting that the situations where falling from a great height whilst sitting in a boat kills you are the bugs and the ones where you survive with no repercussions are the game working as intended.

@SnakebitSTI

28 күн бұрын

The case where the outcome is contrary to the intended logic is the bug. In this case, the intended logic is that being in a boat negates fall damage.

@TimSheehan

28 күн бұрын

​@@SnakebitSTI it clearly started life out as a bug which they've kept around because people like it's quirky/exploit nature.

@zocker1600

28 күн бұрын

@@TimSheehan > a bug which they've kept around because people like it's quirky/exploit nature. it is a feature then, not a bug

@TimSheehan

27 күн бұрын

@@zocker1600 ... you know that "not a bug its a feature" phrase is from people making fun of buggy/ faulty things right? E.g. Oh the door handle has fallen off... Not a bug its a feature car is very secure against breakin now!

@PandaFan2443

27 күн бұрын

​​@@TimSheehan It becomes a feature once its presence becomes intentional. Your examples are different.

"Multiples of 5, in my opinion, are at least 5 apart." -Peggy Hill

but then matt had a very good idea. he used f5. you see, using f5 gave him a whole new perspective and he was able to see a floating point error he couldn't have seen before.

Programming tip of the day: floating-point values that get repeatedly added should, whenever possible, be chosen to be exactly-representable numbers. Instead of 0.04, the acceleration should have been chosen to be 0.0390625 ( = 1/32 + 1/128 ); then the problem would not have arisen. (In memory of the late Garry Tee, who taught me this many years ago. Rest in Peace.)

@Shaddymaze

Ай бұрын

Great tip!

@arcaneminded

Ай бұрын

I did not expect to get this kind of wisdom from a youtube comment. Thanks.

@derekjc777

Ай бұрын

This may solve the problem of repeated adds, however because of the use of the mantissa and exponent in IEEE floating point representations that is not guaranteed. This would produce deterministic results in fixed point arithmetic with 8 bits or more reserved for the fractional component. However, this bug is actually due to floating point/integer rounding errors and therefore your suggested improvement is not a solution.

@christianbarnay2499

Ай бұрын

My programming tip is only use floating points when absolutely unavoidable. If you are only using numbers with a fixed number of decimals, prefer switching the decimal point and using whole numbers for all the calculation. For example properly coded accounting applications use whole numbers to represent the value in cents, not floats to represent the value in dollars with a decimal part. And in modern languages, there is even a "decimal" type that is specifically designed to do that for you.

@hanifarroisimukhlis5989

Ай бұрын

@@christianbarnay2499 Yeah no. Many times, fixed-point math can actually be *slower* than floating-point counterpart. Like multiply/divide across multiple orders of magnitude, trigonometry, exp/log, etc. Point being (pun intended), modern computer are absolute beast when numbercrunching IEEE 754 floating-point, to it being a measure of power (FLOPS). I would dare to say the inverse, *don't* use fixed-point unless you absolutely sure: 1. All numbers fits, including intermediates. 2. Has sufficient precision that is more than standard floating-point. 3. You *really* need that extra precision, with trade-off of more memory/register/cache/etc. 4. Use good generic fixed-point library (don't try to manually implement, it's 100% not worth it).

As a programmer, floating point imprecision has been cause for may hours of desperate debugging.

@adfaklsdjf

Ай бұрын

And why I avoid floats unless I'm _really_ certain I need them

@pinkraven4402

Ай бұрын

​​@@adfaklsdjfI remember that once I actually created a class 'fraction' that had integer numerator and denominator to be able to compute some numbers exactly, I remember I needed it for something haha

@gottagowork

Ай бұрын

I'm not a programmer, but I did some gauge stuff for Flight Sim back in the day. One involved some INT(float) operation that wouldn't work (iirc I was converting to octal for transponder), and I was completely unaware of the float rounding error. Obviously, my "programming" failed and I couldn't figure out why. So I set it up in Excel to see what was going on, and to my amusement even excel did it wrong. Only when I expanded number of decimals did it show i.e. 4.9999999543xxx instead of 5. I've been aware of it since, even if I've never had to deal with it again.

@Sopel997

Ай бұрын

it helps when you understand that they are in fact precise, just inaccurate

@ahall9839

Ай бұрын

​@@adfaklsdjf Why would you be using any data structure that you aren't sure you need?

A Camman18 Matt Parker crossover is NOT something I expected but I thoroughly enjoyed

Finally, a video that combines three of my favorite things. Mathematics, floating point number tomfoolery and Minecraft.

@Vifnis

23 күн бұрын

People who code in Java must love this!

@maticjurac

23 күн бұрын

@@Vifnis I do 😅

@mikeuk1927

11 күн бұрын

Now go compute some inverse square roots :p

I like that, as soon as he told the numbers where that happened, my first instinct was to pause the video and put the sequence on OEIS. Next scene is he putting the sequence on OEIS and finding nothing.

@Benw8888

Ай бұрын

I just wish he tried to find a pattern on his own for a bit longer, both before OEIS and especially after OEIS failed. That feels like a more rewarding way of doing things.

@tulliusexmisc2191

Ай бұрын

I am disappointed that as of the start of April 2024, it is still not in OEIS.

@Universal_Craftsman

Ай бұрын

Now the "Minecraft Boat Fall Damage Sequence" will be introduced to OEIS.

@BrainyGreenOtter

28 күн бұрын

I asked ChatGPT (not the best option, I know, but it was worth a shot) It started strong (-ish?) and then started (convincingly/confidently) pulling stuff out of it's virtual arse. :)

@Hexa1123

28 күн бұрын

Same.

Oh this is SO funny to see a video about this. Fun fact--since most players have no clue about this and use driving boats off ledges as a safe way to get down cliffs, you can often trick people into exploding if you measure out a drop that's exactly the right height. It gets a bit into the weeds, but the historical reason for the "don't calculate fall damage if you're falling" stuff is that boats used to break if you rammed them into land. That got removed, but the fix was kinda a hack and accidentally left this method in.

@LeeAnnC

Ай бұрын

Thank you for reminding me of this! I felt like i was missing one piece of information and i think this was it. Boats used to break and now they don't! Matt keeps talking about a fall damage calculation but I think a better name would be *collision* calculation. And to protect them against damage this is the code they added which in turn inadvertently also keeps the player from damage as well!

@SteinGauslaaStrindhaug

Ай бұрын

So the bug isn't really that the boat breaks at certain heights, but that the "avoid having the boat break all the time" workaround causes a bug where you _incorrectly_ don't receive fall damage while sitting in a boat _except_ with these rounding errors.

@LeeAnnC

Ай бұрын

@@SteinGauslaaStrindhaug this is a good way to put it!

@TheAechBomb

Ай бұрын

I remember boats breaking... I always hated that but maybe I should go back and play old minecraft

@frankcl1

Ай бұрын

​@@SteinGauslaaStrindhaugit used to be a bug, now it's a feature!

An interesting thing is that the boat breaks into sticks and planks. And here's the thing, once upon a time boats were really fragile, they would break from crashing too hard, and they of course also break when you hit them, and in both of those instances they used to break into blocks and planks. Then in an update a long time ago they made it so that they don't break as easily (can't break by crashing) and if you break them by hitting them they drop themselves (or in other words a boat item). But with that bug they still drop the old drops.

I wonder how related this is to Minecraft's weirdest death message: "death.fell.accident.water"? That death message only happens when falling a specific number of blocks down onto a waterlogged slab (half block with water on top). Normally water cancels fall damage, but in this one case it doesn't and it gives a very unusual death message about dying by falling into water.

@schwingedeshaehers

Ай бұрын

how is waterlogged counted? because i think it is, when you hit a solid piece of a block, that is also waterlogged

@VoltisArt

Ай бұрын

I do not know, but it seems possible that it's the same issue between the math and the conflicting status.

@BlueCyann

29 күн бұрын

@@VoltisArt Maybe it's when you get a fall damage death (some kind of floating point issue) while the game is telling you you're in water.

@maxastro

29 күн бұрын

I would bet nearly any amount of money that the death happens when your falling speed is such that after one "tick" you are exactly aligned with the top of the slab, having been outside of the water the previous tick. I can think of several different code weirdnesses that could actually be responsible for the death, but I bet that's the edge case regardless of the specifics.

@zipfling11

28 күн бұрын

I think that message occurs because the developers didn't account for you dying in that specific way, and didn't assign a proper message to play when it happens.

9:08 when you're under water, you can be neither in the air nor in the ground.

@pinkraven4402

Ай бұрын

I mean, unless you're on the bottom

@haiperbus

Ай бұрын

if you jumped into a cobweb or are sliding down honey as well

@RealDanteS01

Ай бұрын

My first thought was that it might apply to ladders.

@FreekDijkstra

Ай бұрын

My first thought was "when you're swimming in lava". I guess that resembles my fortune, errr, skills, when playing Minecraft. :)

2:50 You can use levels of snow for 1/8 of a block precision with some additional levels at 1/16 - carpet, 3/16 - trapdoor, 9/16 - bed, 15/16 - grass path (I could've forgotten something).

@TheRenaSystem

Ай бұрын

Bells, enchantment tables, cakes, are some more specific ones, but (and this is slightly cheating) there's also falling ANY distance up to 0.01 precision by falling sideways out of a water stream or honey blocks (or even technically off of vines/ladders/scaffolding but that's way harder to be precise ironically)

@fwiffo

Ай бұрын

Are you actually lower than a block on soul sand or is that implemented differently? It's unlike grass paths because you can place rails and redstone.

@DreadKyller

Ай бұрын

@@fwiffo Yes, you are lower, which is why you can get effects from blocks below the soul sand, if ice for example is below the soul sand you will find it gets slippery, and this isn't hard coded, it's just the fact that the block your feet are in is the block above the ice. You can also see the Y coordinate in F3 go down when you step on soul sand.

@Arkios64

Ай бұрын

@@fwiffo I'd guess that Soul Sand simply has a lower collision for the top part, so it isn't actually a full block, only visually represented as one.

@lordlightspeed

Ай бұрын

​@TheRenaSystem and different stages of amethyst shard growth, pitcher plants, and...

1:08 - looking at this offhand, there is some patterning here: 12 and 13 have a difference of 1 49 and 51 have a difference of 2 111 and 114 have a difference of 3 202 and a perhaps missing 206 would have a difference of 4 310 and 315 have a difference of 5 I'm not sure what is placing these pairs, but I hypothesize that 206 is also a height from which you would die, and that the next two heights would have a difference of 6 between them. If 206 doesn't work, perhaps that is for a significant reason? edit- oof it was 198! so my hypothesis was actually not too far off then, nice!

@ps.2

29 күн бұрын

Yeah the missing 198 is at least part of what kept me from seeing a pattern.

@jordanberndt4157

18 күн бұрын

Yeah, I'm bad at maths but decent at pattern recognition and the pattern didn't take me long to see: Along with what you said, the distance between each pair of numbers is: - 36 = 12×3, - 60 = 12x5, - 84 = 12x7, - 108 = 12x9, Following the pattern, the next 10 numbers in the sequence would be: 447, 453, 609, 616, 796, 804, 1008, 1017, 1245, 1255...

Never in my life did I think Camman18 would end up in a stand up maths video. We truly live in one of the times.

Didn’t realize there was an online encyclopedia of integer sequences, but thats pretty neat

@nocturnomedieval

Ай бұрын

You watch at Matt Parker not knowing numberphile's most featured website? Quite suspect

@stevesmith2044

Ай бұрын

Neil Sloane

@nekogod

Ай бұрын

They have the founder of it -Neil Sloane on quite a few numberphile videos. He's pretty cool

@NotKyleChicago

Ай бұрын

I think Matt has a copy of the EIS (i.e. the printed version, before it was the OEIS).

@shingofan

Ай бұрын

@@nocturnomedieval They're probably new here - be gentle.

The rabbit hole for Minecraft gravity goes so much further! Turns out most different entities experience different accelerations due to gravity, and different drag forces too! Boats are the simplest, since they don't experience drag. As an example, players and most mobs experience 0.08 b t^-2 of acceleration, or 0.01 b t^-2 if they have slow falling, and experience a vertical drag coefficient of *nearly* 0.02, and a horizontal drag coefficient of *nearly* 0.09 (just as in the video, these "nearly"s are due to floating point errors). Drag is calculated after applying acceleration. Another example would be projectiles, all which experience ~0.01 drag in all directions, but in this case drag is calculated *before* acceleration! Every projectile experience different gravity though: the ones that stack to 16 like pearls, eggs and snowballs experience ~0.03, while potions, arrows and tridents experience ~0.05, llama spit experiences ~0.06 and xp bottles experience ~0.07.

@PromptCriticalJello

Ай бұрын

I'm just surprised that SciCraft hasn't figured out how to hack Minecraft physics using this.

@Kirby703

Ай бұрын

I was looking into horse jump heights a while back and found out that if you're riding a horse in moderately-recent versions, it experiences .02 vertical drag twice per tick, or around .0396 per tick. Do you know if other entities experience this sort of effect in any direction?

@kito323

Ай бұрын

I was about to comment that I remember seeing somewhere some acceleration graphs for MC and they weren't constant and then the higher numbers in Matt's sequence prolly won't work but you pointed it out way more detailed *kudos*

@LunizIsGlacey

Ай бұрын

@@Kirby703 As far as I'm aware no, but I haven't looked much into mobs riding other mobs like in this case. Maybe that could be something interesting to look at...

@sky01james28

Ай бұрын

One time I was modding a monster that jumps in the air to land on the player and crush them, and I was having *so* much trouble until I discovered Minecraft has **different air resistance** for *vertical* and *horizontal* motion 🤨

The tolerance for 'in air' Was likely implemented due to something like a path block being very close to, but not quite a full block. If the game considered you airborne for that moment, it would feel clunky and not let you jump. Especially if you had one foot on the grass and another on the path (depending on where the ground check is measured from) It could also be to ensure your character remains grounded during little rounding errors like that Super cool break down!!

Since you covered Minecraft, maybe have a look at the famous overbounce bug in the Quake3 engine (idTech3). Here also when you drop from a certain height, you get an "overbounce". In short, all your falling velocity gets "bounced" in your direction of travel tangentially. Though even more special, when your horizontal speed is exactly zero when the overbounce happens, you would bounce back up to the start height. This can be used in some maps to gain additional speed or each certain places more easily. Overbounce is kinda funny because there are several "variants". First of all the height above the ground is the most important factor. However you could always simply drop / walk off a ledge or jump off that ledge. Two different heights as a result. Furthermore your player could be in a "sticky" state as it's usually called. That state means your character is not perfectly on the ground but essentially hovers a tiny bit off the ground. You can get to this state either by stepping on a certain stair height and back off. So your falling velocity is just right that you get into the sticky state. Another common way is to use a single shot of the plasma gun to the ground you're standing on. The impact has a slight knockback and lifts you a tiny bit in the air (with the right angle against a wall you can actually climb walls). When you are sticky, the drop and jump heights for the overbounce to happen are different. Another way to get to a certain overbounce height is to do a rocketjump into the ceiling of the map. In some maps the distance from the ceiling to the ground is just right. Some mods (like DeFRaG) had built-in indicators which can tell you if you are "sticky" and if the surface you're looking at would result in a drop or jump overbounce. It's quite handy for finding great trickjump spots in maps. Q3 was and still is one of the best FPS shooters of all time. The physics and netcode are just perfect. Since the Q3 source code is released under the GPL (John Carmack, the hero) we can exactly see what the code does. The overbounce "bug" is also the result of a feature (specifically that you would slightly bounce of walls when you run into them at an angle) and a safety threshold (specifically you're considered on ground when you are less than 0.25 units off the ground. You player is 48 units in height). Here's a video that goes through the code to explain what happens: ( WmO2cdTU7EM ) and here's a defrag video from the 2017 world cub (round 6 is my personal favourite, but the final round is also sick ^^): ( cCO9QuV-cgM ). In Round 6 DeX reached about 1800 ups (units per second) with vanilla Q3 physics. Apart from VQ3 there's a modified version called CPM (Challenge Pro Mode which has some changes, especially more air control and fast weapon switching). "inder" reached almost 3000 ups in that map. The normal runspeed is 320 ups :) I played a lot of defrag but never was even close to be considered a defragger :D Pro players are just crazy people.

you can actually fall down non-integer heights, falling from different snow layers or from cakes, beds, enchanting tables, .... has anyone looked that those?

@davidbarroso1960

Ай бұрын

it rounds to the nearest number of blocks fallen minus 3 (meaning first 3 blocks don’t deal damage, every block afterwards deals 1 point of damage). so if you fall 3.49 blocks, you take 0 damage. if you fall 3.5 blocks, you take 1 point, half a heart of damage.

@yonaoisme

Ай бұрын

@@davidbarroso1960 but would you take damage in a boat if you fall 12.5 blocks, for example?

@auseawesome9112

Ай бұрын

@@davidbarroso1960That doesn't matter, because floating point inaccuracy could still occur and place you very slightly above the ground

@auseawesome9112

Ай бұрын

@@yonaoismeI'm assuming it hasn't been tested yet because it isn't really necessary to fix the bug, but it could be really easily tested by spawning boats with command blocks, slowly travelling upwards by using an invisible armour stand

@davidbarroso1960

Ай бұрын

@@yonaoisme no. for you to take damage, the resulting position has to be “equal” to the floor position. but the resulting position never ends in .5, so it’ll never equal the floor position if the fall height ends in .5.

Stand-up Code Review

@TheGreatAtario

Ай бұрын

_[Agile/Scrum PTSD intensifies]_

@slice-the-pi

26 күн бұрын

oh god please no

Ladder is probably an example on "Not on ground" but "Not in air"

8:48 the game does do a check for when your head is underwater, which divides your mining speed by 5 unless you have aqua affinity on your helmet, and the same occurs when "in the air" (including creative flight in survival mode, but that requires mods or server plugins), not sure if those affect anything in this case, but they do combine (atleast in 1.10.2 that i have open to afk)

8:50 one example is having your upper body in the water (technically "swimming"), or in a cobweb.

Stand-up Maths is slowly becoming a Minecraft stan

@rhysbaker2595

Ай бұрын

Stan-up maths

@spacelover4106

Ай бұрын

Stand-Up Crafts

@babilon6097

Ай бұрын

And the bad thing about this...

@yty1941

Ай бұрын

@@babilon6097 Is that nothing ever goes wrong with a bit of Math, right...

@davidioanhedges

Ай бұрын

At this rate Matt will have to actually play it...

in air and on ground are separate to allow for easily coding things like ladders, platforms, bouncy slime blocks, swimming, floating in lava, lots of stuff.

It is often done on platforming games, where the platforms actually extend a little further out than it looks, to account for input lag and so on. Developers found out, that if you don't add this compensation, it makes the game extremely hard (some of the early games known for being difficult were difficult exactly because of this ) My guess is, that this is to make jumping block to block easier. I had watched a video about this a while ago, but I can't remember what it was called.

This also makes ROUNDING a number an actual nightmare, because XX.5 might actually be XX.49999999 or XX.500000001 and you just can't tell

@TroyLaurin

Ай бұрын

Rounding floating point numbers is a legitimate nightmare that you should only do if you don't actually care about the result being consistent with anything else in your system.

@jesselapides4390

Ай бұрын

Thankfully 0.5 is exactly representable in binary

@TroyLaurin

Ай бұрын

@@jesselapides4390 yes, but should 0.1+0.4 round up or down? Should 0.1x5 round up or down? Should 0.05x10 round up or down? If you're dealing with precise numbers you usually don't need to round

@xanderh2404

Ай бұрын

@@jesselapides4390 Sure, but not all numbers with a .5 at the end are representable. For example, the number 65166464.5 is stored as 65166464, which means if you round 65166464.5, it will round down instead of up, like it should.

@syirogane

Ай бұрын

@@xanderh2404 You cannot store 65166464.5 in a 32-bit float. You can't store even 65166464 vs 65166463 in a float (ie, you'll get the same value (65166462 to 65166466 all "round" to 65166464))

14:40 The short stops at 315 because that's the longest drop you can achieve within the buildable height of a Minecraft world, which goes from y=-64 to 320 for a total height of 384 blocks.

@sky01james28

Ай бұрын

While true, I feel like I should point out that data packs can change worldgen to go from -2032 to 2032 minecraft.wiki/w/Custom_noise_settings

@Skeke

17 күн бұрын

Yeah you're right

underwater would put you not ON_GROUND while neither IN_AIR but more importantly these seperate values play different roles in applying gravity & using player's oxygen underwater

That's why we usually try to avoid floating numbers in programming! Excellent video, enjoyed every second of it.

08:48 I think the reason for having the additional onGround variable is because you can swim in Minecraft too (i.e. not in air, and not on ground)

@Khantia

Ай бұрын

Which can be covered by the status "is_swimming" or something :P

@reilandeubank

Ай бұрын

yes. there can often be good reasons to have an enum status variable but also a bool that covers a specific case of that enum

@bilboswaggings

Ай бұрын

​@@Khantiathat would bloat the code and if you add enough stuff like this your performance will suffer It's more efficient to cover all 3 options with just the two states

@Khantia

Ай бұрын

@@bilboswaggings first time I'm hearing of such practices... since when is it more optimal to check if (this.status == ON_GROUND && !isGrounded) instead of just (this.status = IN_WATER)? Computation-wise the latter option is more efficient. It makes little sense for this to be the reason for the existence of isGrounded :P

@bilboswaggings

Ай бұрын

@@Khantia as shown in the example both are needed for the game to function as it's built Adding a status for in water would also require you to add the code necessary for that check (how else would you know what the status is)

As a programmer working with geometric operations, I hate floating point numbers. They're the worst.

@SushiElemental

Ай бұрын

Wait until a work colleague wants to use floating point numbers with currency 😨

@octopoDEEZ_NUTS

Ай бұрын

@@SushiElementalDo it and pull an Office Space 😂 (but unlike the movie, do your arithmetic correctly)

@SushiElemental

Ай бұрын

@@octopoDEEZ_NUTS Haha I'll think about it 🤓

@bobson_dugnutt

Ай бұрын

@@SushiElemental There's an open source ERP (not super well known but actually used by some companies) that uses floating points for currency. ERP does inventory, accounting, etc. One of the many reasons that made me want to tear my hair out when working with it.

@SushiElemental

Ай бұрын

@@bobson_dugnutt It seems some people just want to lose money.

Did not expect another Minecraft video, but I'm very glad to see you looking into this!

I was taught when I learned to code in the 1970s that all floating point checks need to use a precision check, and never a strict equality check for exactly this reason. The problem here is that they implemented the status check correctly, but the on ground Boolean incorrectly. I always thought that the equality operation on floating point variables should cause a compile-time error.

I was surprised to hear absolutely no mention of terminal velocity in this video about acceleration due to falling, so I did a bit of my own investigation and it turns out that although Minecraft does have a terminal velocity, under these specific conditions the boat/player would not be falling long enough to achieve it. 🤓

@Baddaby

Ай бұрын

When would it though? Considering the video deals with all the height values in MC

@intan4722

Ай бұрын

@@Baddabythere are ways to launch a boat upwards so it goes above build height, like hooking a bunch of fishing rods to it and pulling them up at the same time

@PrincessTidge

Ай бұрын

@Baddaby Okay, this is an excellent question because my initial answer would have been: "Because of the build height limit in Survival worlds there is only enough height in Sandbox worlds to achieve terminal velocity so Matt must be testing in a Survival world... etc" BUT after reviewing the video again it does appear that Matt WAS indeed testing at heights above the Survival height limit (it makes sense that one would do certain tests in a Survival world) so in theory some of the higher tests should be reaching terminal velocity and no longer be subject to acceleration, so what's going on here? 🤔 I did a little more digging and my current theory is that he is testing on a Super Flat world that starts at Y=60 and bedrock is directly beneath one layer of Grass blocks, which would potentially reduce the maximum falling distance by 60 blocks e.g. a result from Y=300 is actually only falling 240 blocks. Again I could be wrong, perhaps Matt is the only person who can answer this, I wonder if he considered terminal velocity at all or if it would even effect the results but I feel like it should, right?

@PrincessTidge

Ай бұрын

​@@Baddaby *deep breath* And just to complicate this further, terminal velocity in Minecraft is different for different entities! For a; Player=78.4m/s, Item or Block=40m/s, Arrow=100m/s I don't know which of these is applicable for a player in a boat, your guess is as good as mine 😂

@icedlava7063

Ай бұрын

what's the point of the emoji?

matt parker camman18 crossover is not what i expected today

thats it not how vertical movement in minecraft is calculated at all

I used to have to deal with this problem a lot. Not only does it effect falling but also teleporting/moving large distances within a tick, the FP error would expand. As I was moving player relative to a structure that moved with them, this cause me many headaches.

Both for this and the first Minecraft video, Matt specifies 'for those not familiar with Minecraft' that they shouldn't worry about not knowing. Now I'm curious how big an overlap there is between the "knows about minecraft" and "watches Matt Parker videos" demographics.

@Neo-vz8nh

Ай бұрын

I would guess that some of Matt's viewers play minecraft as it is probably popular in programers too. But most of the minecrafters are probably children who do not know Matt and math.

@Billycca3

Ай бұрын

​@@Neo-vz8nhnerdy 20 year olds likely make up a sizable chunk of his audience and I'd bet those people grew up on Minecraft (or were at least around it) and would have played Minecraft. Though I agree that obviously the majority of Minecraft players have never seen one of his videos

@jackradzelovage6961

Ай бұрын

i watch(ed) ilmango on the scicraft server and i watch people like marcel vos in openrct2 and im also here, so theres at least one XD

@BobCat0

Ай бұрын

Someone made a CPU in Minecraft. Like a .0000001 MHz 8086 or something.

@breznknedl

Ай бұрын

@@BobCat0someone also made a 1 hz cpu in Minecraft. Most other ingame redstone computers run way slower though

8:56 While not on the ground but also not in the air, you could be swimming in water, swimming in lava, falling through packed snow, or falling through the Void (basically the out of bounds area). These are just what I could think of off the top of my head.

@LdyVivianne

Ай бұрын

Stuck in a spider web…

@xycrypt

Ай бұрын

perhaps falling inside of a non solid block like fire might not count as in the air? just a thought

@Halinn

Ай бұрын

Climbing a ladder

@SomeoneBeginingWithI

29 күн бұрын

@@Halinn would you be in the air while climbing a ladder? or are you just "in" the ladder?

8:53 I beleive if you are in water/lava/cobwebs you aint in the air but aint on the floor either

A note for people why we don’t see the larger values in game like a 447 block drop is terminal velocity. At some point the game will stop accelerating you, and so a drop from anything above will count as the same value. I’m curious if we used a mod to prevent terminal velocity how high we would see these values before the inaccuracy went out of the “close enough” zone entirely

With regard to the bit at 10:28, this is actually the normal, correct way to compare floating point numbers. The fudge factor even has a name, epsilon. You _never_ do a strict equals comparison on floats, because it'll be false unless you're comparing something to itself or to zero. Instead you check if it's within some range, like above or below a target value. You add or subtract epsilon from the value as appropriate to account for the rounding errors.

@AlRoderick

Ай бұрын

So does that mean that when you use the standard == comparison operator in your code that under the hood the CPU is actually subtracting one from the other and checking that the result is within plus or minus epsilon of zero? So that in something like Java, that's a thing that's being done without the programmer necessarily knowing it?

@byeguyssry

Ай бұрын

@@AlRoderick I think it's something the programmers integrated (and OP just means it's common)? Because I definitely have been screwed over by this before

@catmacopter8545

Ай бұрын

​@@AlRoderick actually no! "==" does a direct comparison, which is why 0.1+0.2==0.3 (as floats, idk about doubles) returns false. There is probably some package for comparing floats somewhere :)

@outputcoupler7819

Ай бұрын

@@catmacopter8545 Yup, exactly this. The language can't make the == operator do this by default because somebody someday might actually want to do a true strict comparison of floats. Math packages will usually have a way to do this, or you can just do it yourself. It's not exactly a common problem, most of the time you're working with integers (not necessarily the _datatype_ integer, the mathematical integer).

@kibels894

Ай бұрын

@@AlRoderick No, == does an exact comparison, which would cause you to fall through the ground unless you were clamping the value, because you would never exactly be at the same level as the ground. Clamping instead of comparing an approximate value may be a way to fix this bug though, like only comparing if you are at or below the ground and correcting the position to be exactly equal to ground level to avoid ever rounding in a way that causes fall damage.

I was NOT expecting such a good explanation from a non-minecraft channel

I think you forgot to add 198 in the shot at 14:17! Great video regardless :3

I heard the opening line as "If you are named Natalie..." before the context based autocorrect kicked in.

11:00 The reason why the check has a tolerance on it is precisely because of those pesky binary floating point problems you tend to run into. Since you can never be *quite* sure you end up at exactly a whole number when doing calculations, an easy workaround is to just check to be within a 0.001 margin of it. Yes, we programmers are lazy and can't be bothered to do this properly 😎

@chrishillery

Ай бұрын

Pretty sure that IS "doing it properly", given the context of the problem.

@JochCool

Ай бұрын

​@@chrishillery I would argue it's not, because you're not getting the analytically correct answer for any given input. Floating point was designed to be a jack of all trades format; it's good enough at representing basically any kind of number, but not the proper way for anything specific. In this case, a proper way to do it could have been to store postion as an integer multiple of 0.04 (essentially, a fixed-point format rather than floating point). This way you can get a proveable, exact algorithm.

@chrishillery

Ай бұрын

@JochCool Sure, that's why financial apps don't use floating point. But that's what I meant by "the context of the problem". *Given that* you're working with floating point, the only valid implementation of "equals" is that kind of epsilon comparison.

@buttonasas

Ай бұрын

​@@chrishillery I still disagree: there already exists code that makes sure you don't fall through the ground - the code that checks for collisions. If you can detect for collisions, you can certainly check whether you have "finished falling" and are, in fact, on the ground, in the exact same way as the collision - this should hopefully eliminate the distinction of becoming "on ground" and touching the ground. But hey, the margin is a neat trick that probably made for less code and fewer bugs than my idea, so I don't mind it.

@BryanLu0

Ай бұрын

​@@JochCoolActually, your position isn't limited to 0.04 increments if there are forces other than gravity

as of this comment, the sequence is still not in the OEIS but I don't expect that to hold forever

@cadekachelmeier7251

Ай бұрын

This is entirely dependent on the 0.04 acceleration constant, so it doesn't really seem like something they would add. "Integers 1/25th of a triangle number" is pretty arbitrary.

@cameron7374

Ай бұрын

@@cadekachelmeier7251 Methinks we need a way to search the OEIS for sequences that are offset or a multiple of some sequence then. Because triangle numbers are probably in there and would come up.

@aikumaDK

Ай бұрын

"Block heights in Minecraft, from which being in a boat will not save you from fall damage"

@LethalChicken77

Ай бұрын

​@@cadekachelmeier7251as if they don't have completely arbitrary sequences

@slawless9665

Ай бұрын

@@LethalChicken77 they do but they try to keep them to a minimum . . . however I think an exception will probably eventually be made for this sequence, just because it's in this video.

Floating point inaccuracy was one of the reasons why Universe Sandbox could not use CUDA acceleration for its orbital simulations.

Wait - was this not submitted as a new sequence?! Seems worthy.

the fact that the boat breaks into planks and sticks is incredibly interesting and likely due to vestigial code. Back in the day if you ran into a shoreline, your boat would break into sticks and planks but now, there are no circumstances in normal gameplay where that should happen, if you break one by hand, it drops the boat item itself so there must be something else going on that makes the boat shatter at those particular heights

@Systox25

Ай бұрын

They never removed it that you can break the boat. They made it way sturdier and able to pick up.

@ordanarymods4990

Ай бұрын

@@Systox25 but the code is vestigial because these bugged block heights are the only time breaking a boat drops sticks and planks now

@Systox25

Ай бұрын

@@ordanarymods4990 thought explosions would also destroy them into pieces.

@LiEnby

Ай бұрын

@@Systox25 fun thing is, it always gives you oak planks no matter the wood type used, meaning you can use boats to convert any wood type into oak

@ordanarymods4990

Ай бұрын

@@Systox25 they don’t

onGround is mostly used for deciding if you should take fall damage or not. This is often used for quite a few fly cheats to prevent fall damage, especially older ones. However, it also prevents ladders, vines, and scaffolding from killing you when you fall onto them.

@chitinousbones9230

Ай бұрын

hi misspotato

@endernightblade1958

24 күн бұрын

wait, scaffolding stops fall damage?

@misspotato813

24 күн бұрын

@@endernightblade1958 I'm not certain actually. I just assumed so because they're just cube shaped ladders, but I haven't actually tested it.

@endernightblade1958

24 күн бұрын

@@misspotato813 i think i vaguely recall them stopping me when crouched at least, but as far as i know without that they’re practically a solid block

@dylan__dog

14 күн бұрын

@@endernightblade1958 if you are holding shift when falling onto scaffolding you will not take any. If you're not holding shift you're taking full dmg

So, a while back, on my channel (in my 2nd Hardcore World) I died and lost my world due to this "bug"; which led to me doing a ton of reasearch and testing on my own (I was able to find the same numbers mentioned here). This is a bug that has been quietly discovered, but the developers did not plan on patching it. Additionally, for those that care, in the event that the player is in a boat, they will take damage at the same levels... unless the boat is stationary in the x&z directions; a stationary boat will not break, so I tend to just stay completly still when boating off ledges higher than 40 blocks. Good video. Have been waiting on this!

0:01 hi, Timed users!

So the real bug is that status and onGround are not using same margin of error

@billionai4871

Ай бұрын

or that they are not updated at the same time. either way, the real bug isn't floating point rounding, but de-sync of state.

you're not on the ground if you're IN the groud, suffocating also void also water and lava also cobweb

@nbboxhead3866

Ай бұрын

If you're in the ground, you count as on the block beneath your feet, I think If you're in the void, you count as in the air but just don't have anything to hit Liquids shouldn't count as in the air or on the ground, and probably don't Cobwebs shouldn't change if you're in the air or on the ground, and they'd just affect your falling speed/acceleration

Seeing camman in a Standup Maths video feels like seeing your drug dealer selling to your teacher

Perhaps fixed precision could be used in conjunction with the floating point math and override the results for the edge case scenarios

Finally tackling the big issues.

Minecraft has some really interesting quirks with the way it calculates fast moving entities. To prevent it going through a block when it's moving extremely quickly, it checks every block position between the entity's previous and current positions, but does this separately for the x, y, and z directions. So it can go through a block diagonally because it effectively moves to its new position along the x direction, then y, then z. Some crazy tnt cannons take advantage of this.

@sanscipher9166

Ай бұрын

Moreover, blocks in unloaded chunks don't have collisions. If an entity is so fast, it moves into an unloaded chunk in one tick, it will go through all blocks it would otherwise collide with in that one tick (before also becoming unloaded)

Minecraft and stand up maths was a collab I never knew I needed. There are so many amazing maths problems in Minecraft, I think everyone would enjoy them

I was curious why certain pairs (12,13 & 49,51) were so close to eachother, the algebra behind it really helps

8:44 Caption error here, “this is just boolean” became “this is just bullying” 😄

@angeldude101

Ай бұрын

There were a _lot_ of caption errors. One of the few times I've turned off non-automatically generated captions other than because it was covering up parts of the video.

@aikumaDK

Ай бұрын

There's been plenty of caption errors in recent videos. I'm almost inclined to volunteer to contribute to the subtitles myself.

@jeffreykirkley6475

Ай бұрын

Hey man, don't be boolean the captions.

@mkks4559

Ай бұрын

There's also "12th" instead of "20th" when talking about ticks.

@yosefmacgruber1920

Ай бұрын

Voice-to-text seems to have quite a problem with uncommon words, nor does it judge well by context. That is also similar to why I do not trust auto-correct. I prefer it mark suspected misspelling and let me correct it myself. Those random word switcheroos are really annoying.

The math and reasoning is sound all around , but i think there's a missunderstanding of the 'why', at around 09:00 , with the whole 'on ground on air' explination, i think that it's not about 'taking fall damage while not being on the air' The actual 'bug' is, when you are on a boat, since you are ON TOP of the boat, 'this.status' is never on_land, so the game basically ignores the 'on.ground' and asumes you are still falling. But in those numbers, the distance from the ground to your character (trough the boat), is so small, it correctly identifies that you did fall and should take damage. I think this reasoning makes more sense than 'taking fall damage when you are not falling'.

@LeeAnnC

Ай бұрын

Thank you! I was confused his explanation here too

@ShivanshSharma

Ай бұрын

So, if they used the same method/formula to calculate when (this.status = ON_LAND) and when (onGround = TRUE), then this bug would be fixed, right? Or are they somewhat different things?

@lazykbys

Ай бұрын

So this is a case where they decided that a bug was a feature, then got a "bug report" for cases where the game was working the way it was originally supposed to? I haven't the words to tell you how much I love this. ETA: Apparently, the "no falling damage while on a boat" thingy was a by-product of fixing a different bug (boats broke when rammed into land or something). Dear gods, how I love it all.

@LagMasterSam

Ай бұрын

Isn't the issue that the boat is breaking, and then the player falls through and hits the ground? The boat, without even having a player in it, breaks from certain fall heights.

@ZonieMusic

Ай бұрын

This makes much more sense! I do hope this gets pinned!

I'm sure the 0.01 block threshold in the ground status check was because whoever wrote it thought, "Well, wouldn't want to fall victim to a floating-point precision error by checking for equality here!" The irony 😂

@mattymerr701

Ай бұрын

That's what happens when you don't use the built-in variables for error like epsilon

Slight correction: at 4:50, you state “now your velocity is 0.14” while it should be 0.16 :) Great video! Didn’t know this yet.

Minecraft!? Heck yeah!

YOOOOO!!!! My favorite math guy uploads a video on MATH AND MINECRAFT?!! While I'M playing Minecraft?!? And while I'm doing Minecraft math myself for Stronghold triangulation?! THIS IS A DREAM!

@parkersummers1287

Ай бұрын

no dream was a different video

@bronsoncarder2491

Ай бұрын

@@Nolys-bk4kd It's a joke. Matt Parker's other video about Minecraft was about the Dream controversy.

@Nolys-bk4kd

Ай бұрын

@@bronsoncarder2491 I get that, but what's the joke?

@nbboxhead3866

Ай бұрын

@@Nolys-bk4kd just a pun on how you said this is a dream because of this lining up with exactly what you're doing, and how Matt released a video about the youtuber Dream and the chances of the item drops of his legendary run. We know you definitely weren't talking about the youtuber, but the pun's still funny.

@JohnSmith-ie8ir

Ай бұрын

​@@Nolys-bk4kd you said "THIS IS A DREAM!", hence dream.

I'm guessing the two bools for on_ground and in_air are because the air one doesn't refer to the "grounded state" (as opposed to falling) but rather whether you're inside a non-transparent block and should take suffocation damage. For the uninitiated, this can be achieved in game through teleport commands, various wall clip glitches, or simply dropping sand, gravel, or concrete powder on your head. I'm not familiar with the source code, but this theory would be further corroborated by a separate boolean for drowning.

For the coding at 09:00 , I'm guessing that anytime you are in a separate "vehicle" such as riding a pig /mule/horse /minecart etc.. , your character isn't touching the ground but isn't in the air either

By the way if you ever find yourself in this situation in Minecraft (trapped exactly one of these numbers in the air with nothing but a boat) you can get in the boat and then, while you’re falling, quickly get out and then back in again. This will reset your momentum from the point you exited the boat, and prevent the bug.

@thesurlywombat

Ай бұрын

You can also just exit the boat right before hitting the ground

@BlueCyann

29 күн бұрын

@@thesurlywombat Yes, this is far easier. Getting back into a falling boat reliably is a little bit tricky, mechanically.

You can actually test this hypothesis by testing to see what happens if you land on certain blocks. Some blocks in Minecraft are not exactly one block tall when it comes to entity collision (e.g. with boats and players), and this height can be measured and checked with regards to collision. (Alternatively, you can manually change the tick rate to check what happens when it changes).

Floating point rounding or truncation errors can be pretty nasty bugs to track down.

2 or so weeks ago, I finished my 3 month long school project on polygonal numbers in certain modulo. This is very close to what you were doing here :3

What I found really surprising there is that for boats, Minecraft doesn't apply air resistance logic! So in theory if you were to spawn a boat at an insane height and go into it, you could reach arbitrarily high speed. This is not at all how the rest of the game works. The player itself has a terminal velocity, because the game takes into account "air resistance" Also Minecraft has different value for gravitational acceleration for different entity types.

@Systox25

Ай бұрын

Someone mentioned here that the boat has a maximum velocity but it needs to fall from higher than here shown

@breznknedl

Ай бұрын

actually, when a player is sitting in a boat, air resistance is added. However this does not appear to be the case for mobs, so when you put a pig with a saddle in a boat it doesn't have air resistance. You can then hop on the pig and enjoy gravity freely

@Systox25

Ай бұрын

@@breznknedlwith enough Hermits with some fishing rods and you got yourself a space program 😂

@YounesLayachi

Ай бұрын

I notice this when speedrunners launch a shulker riding boat high in the sky for transportation. The boat comes down at such speed it looks like teleporting to the ground

I bet there's even more holes if you went from partial heights, such as using snow layers to add 1/8th of a block at a time

@danmerillat

Ай бұрын

No, because 1/25 has no common divisors with 1/8. The closest you get is .125: 2 ticks in you're at y-0.12 leaving you 0.005 above the ground. You'd need an accumulated error of 0.004 to pass the check. The precision error is 0.0000000009, so you'd have to fall for 4.4 million ticks to accumulate enough errors to trigger the bug.

@xa-12musk8

Ай бұрын

It rounds

Dude, I’ve been following this bug for years now, it still gets discussed constantly on Mojira

As a dev that had problems with floating-point precission errors on multiple occasions, i still find it incredibly funny. Imagine if in the real world, if you fell 1 meter you'd be fine but if you fell 1 meter and 1cm you'd break your spine

9:00 as a games programmer and a minecrafter, there is one situation in game where you can be not on the ground and not in the air at the same time, and that's when swimming. In that case, onGround would evaluate to false, but status would be something like SWIMMING, and the game modifies the player physics based on status. onGround just determines if you can jump, start sprinting, and probably a few other things.

@HonestAuntyElle

Ай бұрын

Ladders

@smutnejajo5149

27 күн бұрын

I would guess OnGround is used to reduce your mining speed while it's false (ever tried mining something while on a ladder? It takes like twice as long)

Camman18 in a stand up maths video is something I never expected

The on ground check was originally made so water and lava would be traversable. Over the years they've added a lot of new features that are neither falling, nor grounded. Such as Cobwebs, Minecarts and Ladders, which all have unique identifiers that allow for the game to tell the difference between all these states.

Here is another one that relates to converting items into a bit string, this is useful in bulk storage selection, since its much faster to send redstone signals instead of items. A minecraft double chest has 54 slots for different items, which means that any bit position can only be set by at most 54 different items for all codes. (there are also 27 slots for single chests, 9 slots for droppers/dispensers and 5 slots for hoppers). What are the most amount items you can encode in x bits, where each items has a unique code? One idea would be to use only codes that have only 1 bit set and if those are all exhausted use codes with 2 bits set, and so on. Side question: How many codes are there for n bits where only k bits are 1. (Its the binomial coefficients) Of course we could use we could use a very large number of bits and only encode 1 bit for each items, but that is very wasteful. So another question could be whats the optimal amount of bits to use? If you are intrested in more minecraft meets maths related content take a look at WhiteStoneJazz youtube channel and the 'Encoding items in Minecraft' series where i got this idea from.

Yes! The second Minecraft video on this channel. Minecraft let’s play when?

@valkeakirahvi

Ай бұрын

A series focused on figuring out redstone blind, or something math and noob focused like that would be cool :D

@linomercado

Ай бұрын

Yea he can start by counting sheep and then move on to things like recreating his domino full-adder using redstone.

@nbboxhead3866

Ай бұрын

@@linomercado Domino full-adder using TNT when???

There used to be a bug with boats in the game that they would break extremely easily when using them in water as they are meant to be. I think the fact that players can avoid dying most of the time when falling in a boat is actually a bug that exists because of the code changes done to stop the boats from breaking due to normal use.

8:53 swimming probably. While flying or swimming your mining speed is reduced, so that could be linked to the onGround tag.

not on the ground, and not in the air - swimming in the water.