A New LARGE Game Breaking Glitch in Mario Kart 64

[Music] on october 17 2020 a brand new shortcut was found in mario kart 64. on calimari desert forest 64 found a way to clip through this fence and save almost 15 seconds compared to the fastest previously known strategy this new clip was groundbreaking in the past there have been rare instances of people accidentally clipping through walls but why these incidents happens always remain an unsolved mystery but what if it wasn't just a one-time thing what if it were actually broadly applicable could it be so game breaking that it would revolutionize mario kart 64 shortcuts this is driving through walls in mario kart 64. let's look at cali mary desert why is it possible to clip through this part of the fence but first of all why is it even a big deal clipping through the railway fence has long been known to be fairly easy well to answer that we need to take a closer look at the fence itself in fact let's break it down even further what happens when you drive into a wall walls have a zone that pushes you back if you drive into it the zone is four times a character's size or 22 units wide and a quarter of it is in front of the wall this means that you can't drive any closer than five and a half units from a given wall also if you were to drive into a wall fast enough to be in front of the zone on one frame and beyond it on the next you would theoretically go completely through the wall but how fast would you need to go let's get a sense of scale mario kart 64 despite its visual frame rate of 30 frames per second actually performs a physics update 60 times per second for the sake of simplicity these physics updates will be referred to as frames from now on in fact most of the demonstrations shown in this video were recorded using a special tool to display 60 frames per second for more visual clarity one unit per frame is equal to 12 kilometers per hour so the speed required to go through a wall in a single frame is 264 kilometers per hour at minimum for reference the maximum speed on flat ground is about 83 in time trials and about a hundred with a star in 150 cc in fact if your speed ever exceeds 108 kilometers per hour at any point it will automatically be reduced to below 108 so it seems like driving straight through a wall is impossible what about this fence makes it happen well this fence is actually a double-sided wall which is a little more complex double-sided walls have a strong side and a weak side when approached from the strong side it acts just like a regular wallet would it pushes you back out however when coming in from the weak side you get pushed back out only in the outside zone if you end up in the inside zone the wall simply doesn't affect you that's why it's actually fairly easy to clip through the weak side of a double-sided wall like this fence but here's the catch this is the weak side and this is the strong side it's easy to get through to the inside of the train tracks but then you can't get back out or can you it turns out that there is one edge case where it is possible to get through from the strong side if at the end of the frame your position is exactly on the wall down to floating point precision then you're on both sides of the wall at once and you end up not getting pushed back at all on the next frame you keep moving in this direction and cross the wall hitbox entirely without getting pushed remember though this is floating point precise at this particular position floating point number precision is 2 to the negative 14 or 0.000061 assuming you're driving into the wall from a random position at the required speed of 5.5 units per frame the chances of ending up at the perfect position are about one in ninety thousand if you carefully set up your position you might be getting closer to about one in sixteen thousand but because a full lap with this shortcut has never been done in real time yet if you do get the clip all you would have to do is drive to the finish line to set a new world record or you can pause hit retry and spend the rest of your life wondering what could have been now this allowed for a groundbreaking shortcut in cali mary desert but can this be used elsewhere in the game well unfortunately there are very few double-sided walls in dk jungle parkway the small pieces of foliage in this fence are double sided walls it might be possible to clip through this foliage and get a shortcut out of it but there's already a well-known faster shortcut in the cave so this wouldn't be of any use the only other course that has a double-sided wall is royal raceway here theoretically it looks like it could be possible to clip through this double-sided fence to make this shortcut jump from lower saving a bit of time on every lap unfortunately the angle required to make that jump is not direct enough which means the speed required for the component perpendicular to the wall to be at least 5.5 is simply too much you would think this while in luigi raceway to be a good candidate but it's actually made up of two one-sided walls not one double-sided wall so this strategy doesn't work but what about corners well this is where it gets very interesting for this we're going to take a look at bowser's castle in mario raceway this brand new shortcut uses a type of wall clip called an open corner clip we've seen how wild hitboxes extend in front and behind the wall but what about the side well they don't extend past the end of the wall in fact it's possible to cut through the corner of a wall hitbox if by the end of the frame you're past the edge and out of the hitbox when two walls meet in a concave corner each of their hitboxes stops exactly at the corner leaving an opening behind theoretically it would be possible to drive through this corner if you were in front of the corner on one frame and behind it on the next at this point you're beyond the edge of each individual wall hitbox therefore none of them affect you in reality though to do this at a 90 degree corner you would need to travel 7.8 units in a single frame which is 93.4 kilometers per hour at minimum that's only barely possible in 150 cc using a mini turbo with a star active so while technically possible this can't be applied in time trials where your speed is about six percent lower and where stars aren't available however the wall hitbox often doesn't cut cleanly off the edge like this it actually extends along the closest cardinal direction while walls aligned with each axis do look like this differently angled walls can have varying hitbox shapes depending on their orientation at exactly 45 degrees the wall hitbox always prefers to extend along the x-axis so a 90 degree angle that sits on the diagonals would end up having all of its wall hitboxes extend along the x-axis either creating completely closed corners or completely open ones but more typically corners where both wall hitboxes extend on the same axis are closed corners and corners where they extend on different axes are open corners in an open corner the greater the angle between the two walls to lower the speed required to clip through them the minimum clipping speed turns towards 66 kilometers per hour or the width of the outside wall hitbox at one frame this means that with just the right orientation it's theoretically possible to drive directly through a concave corner in time trials without any mushroom or mini turbo in fact it's possible to clip with a relatively low speed in a few select locations in the game this clip unfortunately isn't actually useful but it is possible because the walls sit right around the diagonals in mario raceway the corner is not 90 degrees in fact the walls form a 135 degree open corner because this wall sits directly on the diagonal therefore the minimum speed required to clip through is 72 kilometers per hour which is just barely attainable in time trials with the mushroom and perfect positioning just clipping through is not enough though to actually get to the other side you also need to jump otherwise you'll just fall out of bounds beneath the track driving through this corner allows for a sub 10 second lap and is therefore the new fastest known shortcut in mario [Music] raceway [Music] [Music] here we go [Music] now if the walls are instead forming a convex angle the open corner situation is a bit different if the corner is open you can get extremely close to a wall but the wall hitboxes behind them are very large and impossible to drive through at mario kart speeds but there is one detail that changes everything allow me to introduce my friend the third dimension this corner is not just open it's also on a downward slope when driving down the slope the interactions on every frame are handled in this order first you attempt to move according to your speed which has a component in all three coordinates then a collision check is made with the walls if you're inside a wall hitbox you will end up bouncing off of it on the next frame after the collision check the slope comes into play and moves you ever so slightly now this tiny position change can actually put you inside the wall hitbox however the collision check was already made earlier in the frame so that collision goes unnoticed but it should be handled on the next frame instead right well it's actually a bit more complicated while hitboxes on the inside are only active if you crossed a wild plane during the current frame you can theoretically stay inside of a wall without being pushed by it for as long as you want so long as you don't actually cross the walls plane as a result after the collision goes unnoticed on the first frame you can just hang out here except there's no floor beyond this point so you immediately fall out of bounds this is what happened to sumik a mario kart 64 player who stumbled upon the clip by accident last year or at least that's what was thought to have happened as it turns out it actually was an entirely different type of clip a slip through if you look closely you can see that he was driving almost completely parallel to this wall when he clipped this is the key element that makes slipping through the wall possible to get a better look at it let's instead consider these walls if you come in from this angle a very specific interaction with each of the two walls can take place and allow you to go through the walls hitboxes extend along their respective closest axis with enough speed it's possible to go from here to here in a single frame even though you cross the wall plane your position at the end of the frame is past the end of the wall hitbox so this wall doesn't affect you now you're inside the back hitbox of this wall but here's the trick if we extend the wall's plane you can see that your position is behind the wall on both frames even though you entered the wall's back hitbox you didn't cross the wall plane so you don't get pushed by that wall either so for different reasons both walls do not push you and you can keep going in this direction in 150cc mode with a star and a well-timed jump it's possible to cut the first loop of luigi raceway with this clip although faster shortcuts already exist on this track to recap slipping through a convex corner is possible if there's an opening between one of the walls hitbox and the other wall and if the intersection of that wall's plane with this front hitbox is at an angle direct enough for this distance to be crossed in a single frame finally there is one more possibility to discuss the scene between a steep floor and a wall at this specific spot in choco mountain this triangle is a steep floor and this one is a wall this means that their hitboxes each extend along different axes creating a gap similar to an open corner between two walls therefore with enough horizontal and negative vertical speed it's possible to clip through the seam in exactly the same way now this specific clip isn't of any use but it opens up an interesting possibility are there any other places where this could be used well unfortunately the set of required conditions is pretty precise there needs to be a floor and a wall joined together with their slopes as close together as possible to find out where these conditions can be met we first need to understand what makes a triangle the floor and what makes it a wall whether a piece of level geometry is a floor or wall is not an inherent property of the triangle it's actually determined by the orientation of its normal the line perpendicular to the triangle if the normal is largest in the vertical axis the triangle will be a floor if it's largest in one of the horizontal axis the triangle is a wall instead but here's an interesting quirk all three axes are compared individually this means that while any triangle that an angle lower than 45 degrees is a floor steeper triangles can be walls or floors depending on their orientation even as high as 54 degrees using this information we can look at possible places where this could be useful but as with other similar clips the yield is disappointing the cave in dk jungle parkway looks promising but the triangle orientations don't work out in our favor the only real use out of it seems to be in koopa troopa beach this one triangle is a floor amongst wild triangles fifteen years ago miles buckrim found it was possible to clip through this corner and that there is ground down there but the real interesting part is that it doesn't have such a number this makes the game think you're a bit further back than you actually are which can lead to better items like a star and 150cc unfortunately though it doesn't set you that far back and the task is already so fast that being set back to here doesn't even let you get a star another possible use would be to set up a position near the finish line then warp to it by falling out of bounds and being dropped forwards by lakitu however because of the setup required it winds up being slower than going around the track normally the only way it could possibly be faster is if you could go straight through the ramp but while there are many ways to drive through walls it's impossible to go through the what just happened here okay it turns out it is possible to get knocked through the route the trick is to hit another racer at just the right angle to get pushed down through the ground and on the next frame be pushed right back in because you're under the floor plane on both frames the other side of the floor hitbox stops affecting you now this could have a use in luigi raceway to reach the tunnel right from the beginning and in dk's jungle parkway to reach the tunnel slightly faster than by turning around like i mentioned earlier it could potentially save a very small amount of time in kupatrupa beach if somehow a cpu could be manipulated into just the right position to make it work but yet again that's pretty much it for possible uses of this trick driving through walls in general is not a fully understood concept yet and more research needs to be done to properly establish just how much of it is possible and how exactly collisions work on top of what was covered in this video there's still more strange behavior that cannot be explained with our current understanding but looking back at all of these ways to clip through walls it's kind of incredible that the overall landscape of mario kart 64 shortcuts isn't changed more drastically as crazy as driving through walls seems to be it turns out that mario kart 64 is already so broken that removing walls wouldn't even break it much more huh forest 64 just found something interesting let's see what it is [Applause] so as it turns out at the very end of this video's production forest 64 proved yet again that you don't need to go through walls to break mario kart 64. in fact all you need to do is ram into them with enough conviction the reason behind lies in the order each interaction is processed on each frame first the movement is made then the floor detection is handled which also updates which section of the track you're in after that wall collisions are processed so by driving fast enough to clear the front hitbox of the wall you can get beyond the wall and into the backhead box at this point the floor below you is in this section of the track putting you half a lap ahead then you get pushed back by the wall into the finish line and the lap counts like the mario raceway shortcut this is doable in real time in time trials and in 150cc this is huge for full game runs and four time trials now again we need to ask just how much does it open up the game well we need a wall or floor with a surface on the other side of it so that on this frame we can do something useful with the other surface there are three potentially useful things we can do with the other surface we could update our section like we did on luigi raceway to be considered elsewhere momentarily we could touch an out-of-bound section on an input frame to get picked up by lakitu and get placed further ahead on the track finally if the surface on the other side is angled enough we could bounce off of it to jump over the wall with these options in mind this time let's go level by level and review every useful application of this trick next on the list is moomoo farm here this trick lets you get out of bounds to be picked up by lakitu which triggers what's called the lakitu effect for the next 95 frames you can travel out of bounds without being picked up again and performing the half clip again lets you bounce off the slope beyond the wall and over into the center unfortunately it's just barely short of actually making a half lap skip possible the distance that needs to be traveled is a little too long to be done in only a second and a half we're a lot closer to an actual time trial shortcut in mumu farm but it's still just out of reach back to the list of levels next is yep that's it while most tracks have a wall next to the finish line most don't have any ground beyond it let alone ground with a section number that puts it far enough into the lab to trigger a lap skip this new discovery ends up only revolutionizing luigi raceway this track with mario raceway and possibly cali mary desert will see new world records and time trials in the coming weeks the all cups with skips run can be improved by a good 10 to 15 seconds on top of that there are many other tracks that could see improvements in the tool assisted setting thanks to forest 64 weatherton in micro500 for working on this project with me and thank you for watching [Music] [Laughter] you

Channel: Bismuth

Views: 249,020

Rating: 4.9589081 out of 5

Keywords:

Id: 2_uRIyAgtpE

Length: 18min 42sec (1122 seconds)

Published: Tue Feb 09 2021

Reddit Comments

[u/columbo222]

This is insane, MK64 is 21 years old, people have been speedrunning it basically that entire time, and yet the past year has found so many new glitches that it's like a brand new game.

Entire tracks that were thought to have no skips now have skips. Old records being shattered by dozens of seconds. Completely new mechanics that weren't even known about. And it's not even a long game!

[u/Templarbomb]

Lmao Abney already got the 3lap SC record on Luigi Raceway before the video even came out after figuring out the trick himself when Weatherton posted flap times on their discord

Edit: and he got the flap

Edit2: improved the 3 lap

Edit3: improved the 3 lap again

[u/CypherSignal]

Yooo that 60Hz gameplay visualization/simulation, though! I’ve never seen MK64 look so clean and smooth!

[u/Lykrast]

Those animations to illustrate the various hitboxes and walls and such were soooooo smooth it was great!

[u/JohnnyLeven]

A new Bismuth video? Yes please.

[u/Kai_973]

I can't watch the video right now, but was this discovery made after Abney's recent ~38 second skips WR/PB?

[u/UltSomnia]

You're amazing BTW! Happy to support you on Pateron!

[u/TheMarioPianist]

Welp given that the LR sc is Japanese version only, guess it's as good a time as ever to get my third copy of this game lol. At least the MR one is all versions.

[u/RJ-does-a-thing]

This is incredible. I've only gotten into watching spreedruns over the last few months, the amount of dedication people put in to finding new tricks or ways of optimising an already incredible run is just amazing. I love how supportive speedrunners are of eachother and how they all share tips and encourage each other to improve.