0:15 "Hello, i think i got the attention of that ship over there! I can lower this platform and get us down there, hold tight until i can bring this platform back up."
"That's the difference between you and me, Morty! I spam dot products when I need to! You're all too happy to be rigid and never achieve any interesting physics!"
I would've liked a computational comparison between the "hard" and soft bodies. Something along the lines of "hard bodies only need to make 1 colission check while the soft body has to do(for squre example, 64 colission checks and 174 spring force calculations" And then showcase the limit before it start lagging with hard bodies and compare it with softbodies. Anyway great video. I like this new type of video.
That's a good observation. You can actually see the frame-rate dip below 60 in a few sections if you really look for it. In sections that featured multiple soft-bodies (mainly the ending shots) I actually remove them completely once the camera leaves to save performance. The stress balls (yes I know...) contain ~600 particles and ~7000 spring connections alone. I've used GPUs to get a set of 10,000 springs working above >150 fps in real-time, but didn't want to redo it for this project.
10:07 This is a Wacky Wavy Inflatable Tube Man. That is the only name you are permitted to call it. Nothing more, nothing less. It is a Wacky Wavy Inflatable Tube Man.
@@acherrysodacan Was just about to make the crucial correction. Good thing there are appropriately-cultured random internet strangers 'round here. 😤😤😤
How would you handle keeping a consistent volume? When you have a body of multiple springs they can keep a general structure, but the volume of the area can vary wildly which can lead to some pretty wacky looking objects.
I don't think I've seen any soft-body simulations that have figured this out yet. I imagine it would be significantly more complicated, since you'd have to actually calculate volume and apply an outward force equal to any inward force acting on the object.
Im pretty sure you have to play with general spring formula and force percents to get each individual effect Man, coding is suffering 😢 Edit: did a typo
If it's a sack of fluid, simulate the fluid or follow the suggestion above and calculate volume and use that as "back-pressure" on any/all the springs. If it's something rubbery, the volume can only "escape" locally, not far away, so you'd need to distribute the pressure locally in the mesh (squeeze one spring, other springs attached to its nodes want to elongate)
@@ClaraCl2005 though i might have a suggestion. If u want to make rubber objects u need to have a center joint that will always push on other ones, and probably connect center joint to outside joints with weaker springs. Also if u want to make an object with different stiffness parts, like a broom, you could use center joints to keep the thing in place. Like, for the broom, make a center joint inside of the fiber mesh and attack those to solid joints in the handle or something, it will correlate deformation of the mesh with other ones so it wont completely flop on the side. This can also be applied to tails or even chains and anchors to some extent
I've been faking water and cloth recently in unreal materials - because doing the real maths is too much complexity for a giant water world and a lot of sailing ships. rather than 'springs' between verts I've been using dampened and shifted sign waves. Works quite well, gives the illusion of cloth and water waves with a fraction of the maths. This soft body demo was very cool man, might have to use something similar for various flora and fauna.
i may not understand all of this math stuff but as a 3d artist i gotta say these videos are awesome. from the editing to the jokes and the actual information. keep it up :3
You can solve most of jiggle physics on a character by rigging the giggly part to a ball constrained to a spring. The ball collides with the hard portions of the parent mesh or the skeleton. Another way is to have a physics active set of bones that are spring tied to the intended animation and the collisions/sudden jolts effect the child mesh
Seeing this reminded me of just how complex the misaligned and open vertices were in Mario 64 and all its invisible walls, floors, and death planes. I can only imagine the chaos that would’ve ensued if there were soft body physics in that game
1:12 As a fighting game player, I believe that they are trying to go in and out of their opponent's attack range, baiting the other to do an attack, only for them to swing and miss, to hit them with an attack of their own. This is known as "whiff punish baiting" and is an important element of the neutral game.
the thing at the end, i always heard people call it the "wacky arm-flailing inflatable tube man" and despite how comically long of a name that is, its accurate enough so thats what ive been calling it too 🤣
If you have your cube with a Shane in each corner and add one in the center of the cube, you have the bcc crystal structure, which room temperature iron uses
@@coolkatboy6991 No idea! I assume it has something to do with his Patreon group? Maybe they have a "spot the card" challenge where they get Nitro or something.
@@evaluator8906 it still uses soft body physics underneath the visible part,its not like flatout 2 where everything is a rigidbody with mesh deformation It uses soft body physics,using a special physics mesh (.jbeam format) and the beams connecting the nodes act as springs So,the game uses the soft body physics to (very simply put) deform the meshes,so they are completely different things,yes but in beamng they are connected to each other
This video is really fun and engaging, I would normally get bored with these topics, but the animations and humor helped me keep hooked and interested!
Small factoid: The "Air Dancer" (US Patent US6186857B1) is officially referred to as an "inflated undulating figure". Peter Minshall came up with the idea, and Doron Gazit helped realize it, then patented the design without Minshall. They were created for the 1996 Summer Olympics and are known by several names, which include: FlyGuy, Tube Man, Sky Dancer, Tall Boy, Inflatable Man, and (my favourite) "Wacky Waving Inflatable Arm-Flailing Tube-Man".
You have forced me to recall my computer modelling course rather than my artificial intelligence course for today, and I am equally confused and amused by the explanations I used to understand. How dare you, and good on you, dude. I wrote a paper trying to explain these concepts. Man, I sucked at it.
NGL, that particle total looks like what you would expect a dude named Shane to look like. That jerk keeps borrowing money from me and takes his sweet time paying me back and is like "I totally got you man..."
I just saw your monopoly video and realized the potential of AI when a developer has too much spare time, I left a well deserved like for you. Could you make a video of you forcing AI to play "the campaign for North Africa" just to see if the game is balanced. Keep in mind that a campaign lasts an estimated 1,500 hours, so you'd be discovering info that others don't know merely because not as many people play that game. It'd be your toughest challenge yet.
really like this style of content! As a small hint/request: it would be interesting and funny to see programming mistakes that lead to funny outcomes. Not too much, but just some unexpected gags or cool visual things
An elegant way of testing whether a point is inside an enclosed N dimensional surface is to cast a ray in a random direction starting at the point, and seeing how many times the ray intersects the surface. Each time the ray intersects the surface it has to cross over from inside to outside or vica versa, meaning that if there are an odd number of intersections then the point must have been on the inside. Though the binary tree method scales better with complex meshes
1:20 they just don't want to be awkward like they respect eachothers personal space but also don't want to stand too far away so they're just dancing back and forth cuz they didn't expect the other one to do the same :D
I wasn't expecting the mechanical engineering summary. "This is called shearing" oh like some comp sci term? No, literally just mechanical shear failure. And of course the whole Hooke's law and spring mass damper thing gave me flashbacks to Controls I
I just discovered your channel and I love your videos! I am 13 and im learning news things without decaying from boredom,I think my school sehould do this because I would actually be interested @@b2stud
VERY awesome video. Informational, and hilarious as always! Thanks for making it! If you're interested, we took a completely separate approach to soft body physics in our game, INK INSIDE. Basically, we baked soft body "squash & stretch" movements into fixed animations. This took a fairly complicated animation rig to pull off, but it saved us massively on performance hits as no physics calculations are done when characters are getting hit by physics objects. Instead, every animation is "pre-made" to perform as if it was a soft body all along. The animation is "canned," but we use a variation of them with minor adjustments so the action appears organic. However, the only reason we can get away with it is because of our art style. (Cal arts / Saturday Morning cartoons). But I figured it was worth mentioning as an option when it comes to making rigid things squash & stretch in a game :)
In Brazil, those dolls are called "bonecos de posto" or "gas station dolls" or "car repair shop dolls", which is where they are seem the most. I actually never saw those outside of those contexts.
0:15 "Hello, i think i got the attention of that ship over there! I can lower this platform and get us down there, hold tight until i can bring this platform back up."
Huh?
I agree with Bomba, huh?
What
Explanation: It's a reference about a game in roblox "Guts & Blackpowder"
BARRYYYY
Interesting thumbnail you got there
it never fails...
“This is hard”
*well it could make things- I hate myself
very nice
How did I miss that?
Well it did work
this video is 60% educational, 30% comedy and 10% fever dream
10%? Ha 😂
For a 10% fever dream this looks quite tame. Instead of eldritch horrors chasing you, you've got funny fish
10%? For me looks like 100000%
I just had a fever dream yesterday and I can confirm
60% educational, 30% comedy, 9% fever dream, 00.2% booba, 0.38% circle fanfic, 0.39% confusion and 00.1% burp.
6:28 i don’t know Rick, sounds really complicated…
😂
I read this is mortys voice😂
nice stress balls
uh.. yeah! stress balls! don't we have them too? like uhhhhhh
nice balls
9:24
Nice balls
2:11
9:24 sure... stress balls.
I mean... to the right person they can be...
I hate myself.
Well, squeeze that "stress balls" is really anti-strees
Anyone else notice bro getting more and more unhinged with each video. This trajectory is concerning.
Why's it matter, we get content
this is the natural progression of any game dev or mod developer
It's called character growth.
@@Well-Rounded_Wildcardfrfr
@@Well-Rounded_Wildcard He is indeed very slowly losing his marbles
Hands down the absolute best patreon plug to be witnessed by man.
6:29 "Morty, you gotta take each **belch** entry in the dataset and add it to the goddamn tree, Morty!"
“Morty! I turned myself into a soft body model Morty! I’m soft body riiiick!!!”
"this'll generate the same tree structure we saw with the numbers, morty"
"That's the difference between you and me, Morty! I spam dot products when I need to! You're all too happy to be rigid and never achieve any interesting physics!"
Bruh, idk why but it started selling after that
I was hoping that someone would make a joke out of it and I'm happy now
8:29 ... who was that speaking? A collaborator? A family member? A fancy AI-generated voice? B2, after intensive vocal training?
No he was just talking normally there?
I love how you left the possibility of a girlfriend off the list
It's zyger
@@tino_-td7ok come on man, we all know getting a gf is harder than solving NP complete...
_why didn't I even question this?_
I would've liked a computational comparison between the "hard" and soft bodies. Something along the lines of "hard bodies only need to make 1 colission check while the soft body has to do(for squre example, 64 colission checks and 174 spring force calculations" And then showcase the limit before it start lagging with hard bodies and compare it with softbodies.
Anyway great video. I like this new type of video.
That's a good observation. You can actually see the frame-rate dip below 60 in a few sections if you really look for it. In sections that featured multiple soft-bodies (mainly the ending shots) I actually remove them completely once the camera leaves to save performance. The stress balls (yes I know...) contain ~600 particles and ~7000 spring connections alone. I've used GPUs to get a set of 10,000 springs working above >150 fps in real-time, but didn't want to redo it for this project.
I'm glad you liked the video, AI is always interesting but there's so much other stuff to explore
8:29 did you have a cold for this part?
My life needs more squishy things
No boobies for you.
mrrw :3
Same man. Same
don't we all?
@@Agvazela_Vega same…
I need some femboy thighs in my life
10:18 Why its a whacky wavy inflatable arms flailing tube man
More people should be aware of its true name, its so beautiful.
@@shark_girl ikr
Reference?
i love you b2 studios i fear youre too iconic for this world
I love you
@@b2stud man I love parasocial relationships ❤❤❤
Is that a threat?
@@TimeTravelingFetus i believe the only threat involved is b2 changing the definition of the word diva to their name
@@4kleidisc b2diva
There was something incredibly unhinged about this video, especially by the end when we had stressballs and hard-to-soft appendages
and i loved it
maybe im just sleep deprived but this video feels so much more unhinged than all the ones youve made before
*The correct, official name for the dancing air dudes is:*
*"Wacky waving inflatable arm flailing tube man"*
Came down here to say this. A man of culture I see.
You can get some at Al Harrington's Wacky Waving Inflatable Arm Flailing Tube Man Emporium and Warehouse on Route 2 in Weekapaug!
Yes it is I even got the search button for it
"this is hard" well yeah then it obviously isn't squishy...
Now I get why youtube didn’t like some stuff in your video
surely it's not that crazy
@@payprice5487crazy enough for 2024 tho.
I like 9:54
what stuff?
I like 9:55 :)
perfect combination of jokes and actual talk that makes the video entertaining the whole way through
9:23 actually made my jaw drop
did it go boioioioing
Ooga booga neuron activation
Vtubers when they move 1 centimeter
@@b____oobies jiggle physics 💀
Time to become a programmer
10:07
This is a Wacky Wavy Inflatable Tube Man. That is the only name you are permitted to call it. Nothing more, nothing less. It is a Wacky Wavy Inflatable Tube Man.
wacky waving inflatable *arm-flailing* tube man. you can't forget the arms.
@@acherrysodacan Was just about to make the crucial correction. Good thing there are appropriately-cultured random internet strangers 'round here. 😤😤😤
*Wacky waving inflatable arm-flailing tube man.
Don't spread misinformation, otherwise you're the news :p
Balloon Guy
Is this a zeronium reference
I love that he not only left a burp in the video, but also put it in the captions too. Dude could not be bothered to re-record XD
How would you handle keeping a consistent volume? When you have a body of multiple springs they can keep a general structure, but the volume of the area can vary wildly which can lead to some pretty wacky looking objects.
I don't think I've seen any soft-body simulations that have figured this out yet. I imagine it would be significantly more complicated, since you'd have to actually calculate volume and apply an outward force equal to any inward force acting on the object.
@@squiddler7731Seems to me like computing a change in volume would be sufficient, and like, *maybe* that could be easier? But idk
Im pretty sure you have to play with general spring formula and force percents to get each individual effect
Man, coding is suffering 😢
Edit: did a typo
If it's a sack of fluid, simulate the fluid or follow the suggestion above and calculate volume and use that as "back-pressure" on any/all the springs.
If it's something rubbery, the volume can only "escape" locally, not far away, so you'd need to distribute the pressure locally in the mesh (squeeze one spring, other springs attached to its nodes want to elongate)
@@ClaraCl2005 though i might have a suggestion.
If u want to make rubber objects u need to have a center joint that will always push on other ones, and probably connect center joint to outside joints with weaker springs.
Also if u want to make an object with different stiffness parts, like a broom, you could use center joints to keep the thing in place.
Like, for the broom, make a center joint inside of the fiber mesh and attack those to solid joints in the handle or something, it will correlate deformation of the mesh with other ones so it wont completely flop on the side. This can also be applied to tails or even chains and anchors to some extent
10:20 wacky wavey inflatable arm flailing tube man!
Yeah Family Guy named these way back in the day.
Incorrect it is a blowdaddy
FUCK
YOU BEAT ME
Did you just say wacky waving inflatable arm flailing tube man?
hahaha
I love you left the huge belch in it was hilarious
Ragdolls + Softbodies = An amazing time. Could make for a fun filler video
I've been faking water and cloth recently in unreal materials - because doing the real maths is too much complexity for a giant water world and a lot of sailing ships.
rather than 'springs' between verts I've been using dampened and shifted sign waves.
Works quite well, gives the illusion of cloth and water waves with a fraction of the maths.
This soft body demo was very cool man, might have to use something similar for various flora and fauna.
4:11 goddamit it's always the little details
The loading screen?
I'm gonna be so sad if we don't get an 'AI Learns Trampolining' video in the future after watching this.
1:11 Don't let the Heavy know your location...
Now I know you're a real game dev. You're getting crazier by the minute
The burp at 6:29 😂
then, morty, like before *burp* we can take each entry...
it's cringe
^ so are you 😊
Me reading this comment right as I'm about to release one myself 💀
what an absolute legend
i may not understand all of this math stuff but as a 3d artist i gotta say these videos are awesome. from the editing to the jokes and the actual information. keep it up :3
You can solve most of jiggle physics on a character by rigging the giggly part to a ball constrained to a spring. The ball collides with the hard portions of the parent mesh or the skeleton.
Another way is to have a physics active set of bones that are spring tied to the intended animation and the collisions/sudden jolts effect the child mesh
Seeing this reminded me of just how complex the misaligned and open vertices were in Mario 64 and all its invisible walls, floors, and death planes.
I can only imagine the chaos that would’ve ensued if there were soft body physics in that game
8:30 WOMAN JUMPSCARE
it was zyger
@@FireBlast2.0who is zyger?
@@cvjlmaker9890 a game developer
I was so scared 😢
literally went to comment the same thing
00:53 I had a heart attack when you said that name.
why? cuz your name is Shane? lol
@@Brandon11746 🫢ummmmm, no?
Hi shane
1:12 As a fighting game player, I believe that they are trying to go in and out of their opponent's attack range, baiting the other to do an attack, only for them to swing and miss, to hit them with an attack of their own.
This is known as "whiff punish baiting" and is an important element of the neutral game.
+3 props points lmao, 1 for keeping the burp in, 2 for each stressball
this is my favourite video of yours so far, i love game dev nerdy stuff and would LOVE to see more
you're in for a treat
@@b2studFIRE EMOJI🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥
the thing at the end, i always heard people call it the "wacky arm-flailing inflatable tube man" and despite how comically long of a name that is, its accurate enough so thats what ive been calling it too 🤣
Wacky inflatable tube man is the name >:(
wacky inflatable flailing arm tube man*
Wacky waving inflatable arm-flailing tube man!
@@chargle*wacky waving inflatable arm-flailing tube men
@@chargle *wacking waving inflatable arm flailing tube man
wacky wavey arm inflatable tube man
so thats what the community post was about…
What
If you have your cube with a Shane in each corner and add one in the center of the cube, you have the bcc crystal structure, which room temperature iron uses
2:53 what is that redeem card?
There's another one too 👀
what is it? i see discord, but i don't know what to do with it
@@coolkatboy6991 No idea! I assume it has something to do with his Patreon group? Maybe they have a "spot the card" challenge where they get Nitro or something.
@@Jademalo Ah good eye!
@@coolkatboy6991theres a bot you can use to create your own fish, and these redeem codes give you points for the shop
Came for the thumbnail, stayed for the amazing storytelling and animation 👌💯
Part of why I love World of Goo and WOG 2, super underrated!
Succulent!
3:11 Those middle springs and that ball make my brain have a complete meltdown ☠☠
9:38 This feels like a callout post especially considering I already did
BeamNG: "Am I a joke to you?"
Slime Rancher watching from the corner:
Mesh deformation and softbodies are two completely different things
Human fall flat: YOU DIDNT INVITE MEEE
@@Somerandofurryomg a slime rancher fan
@@evaluator8906 it still uses soft body physics underneath the visible part,its not like flatout 2 where everything is a rigidbody with mesh deformation
It uses soft body physics,using a special physics mesh (.jbeam format) and the beams connecting the nodes act as springs
So,the game uses the soft body physics to (very simply put) deform the meshes,so they are completely different things,yes but in beamng they are connected to each other
this guy sounds like he's going to break down and scream in pain at any moment
Time to make a game with PLENTY of squishy things.........
8:30 Idk why or for what about, but that voice hit something in my brain. I was genuinely afraid of what was happening for a split second there.
I came to RUclips for safety. Too high and very scared. Why was this fever dream recommended to me?
"stress balls" - uh huh😉
2:13 i did not consent to being touched like this... my lawyers will be in contact...
This video is really fun and engaging, I would normally get bored with these topics, but the animations and humor helped me keep hooked and interested!
I'm glad you enjoyed it!
@@b2studyo ma
this man didnt think the thumbnail mixed with the title through
Small factoid: The "Air Dancer" (US Patent US6186857B1) is officially referred to as an "inflated undulating figure". Peter Minshall came up with the idea, and Doron Gazit helped realize it, then patented the design without Minshall. They were created for the 1996 Summer Olympics and are known by several names, which include: FlyGuy, Tube Man, Sky Dancer, Tall Boy, Inflatable Man, and (my favourite) "Wacky Waving Inflatable Arm-Flailing Tube-Man".
You have forced me to recall my computer modelling course rather than my artificial intelligence course for today, and I am equally confused and amused by the explanations I used to understand. How dare you, and good on you, dude.
I wrote a paper trying to explain these concepts. Man, I sucked at it.
9:57 this implies 4/5 men are either constantly hard or soft forever
I thought he was talking about ED
@@frog_king6517 more than 1/5 of men have had times in their life where they didn't experience ED I'm pretty sure
@@GreenJalapenjo True, I don't know the percentage. That's just how I saw the joke.
no i think this is a joke about someone seeing a trap…
@@ExplodingSteve wait would that imply 4/5 men are into it then?
Luncheon kingdom vibes
Any relation to existing environments is purely coincidental
Very well explained. Easy to understand and fun visuals. I'm impressed
NGL, that particle total looks like what you would expect a dude named Shane to look like. That jerk keeps borrowing money from me and takes his sweet time paying me back and is like "I totally got you man..."
Quality plus unhinged and educational is a beautiful trifecta!
6:29 didn't wanna re-record there?
bro did not wanna re-record there
Listen Morty...we gotta collide the s-UUUUUUGRKHH -oft bodies Morty...we gotta calculate the dot products or we'll never make it back to Earth.
It’s funny
my only thought while dying of laughter was "why would he do that?" but once the woman voice came on I knew it was an artistic choice
I just saw your monopoly video and realized the potential of AI when a developer has too much spare time, I left a well deserved like for you. Could you make a video of you forcing AI to play "the campaign for North Africa" just to see if the game is balanced. Keep in mind that a campaign lasts an estimated 1,500 hours, so you'd be discovering info that others don't know merely because not as many people play that game. It'd be your toughest challenge yet.
4:13 loading had me ROLLING 😅
how could you forget the wacky wavy inflatable arm flailing tube man?
"why aren't games full of squishy things?"
every anime game ever:
2:39 love this part
The laughing is devious 😂
The editing and jokes here and there make this incredibly enjoyable to watch. So much so that i subscribed and commented!
Great video. Only complaint is that this video about softbodies gave me ptsd about trying to develop one before giving up.
giving a thumbs up just for having the nerve to burp right in the middle of a educational video. absolutely feral
I wish all my physics lectures were like this
really like this style of content! As a small hint/request: it would be interesting and funny to see programming mistakes that lead to funny outcomes. Not too much, but just some unexpected gags or cool visual things
What a bloody brilliant video - love it as always!
It’s a Wacky Wacky Inflatable Tube Man.
An elegant way of testing whether a point is inside an enclosed N dimensional surface is to cast a ray in a random direction starting at the point, and seeing how many times the ray intersects the surface. Each time the ray intersects the surface it has to cross over from inside to outside or vica versa, meaning that if there are an odd number of intersections then the point must have been on the inside.
Though the binary tree method scales better with complex meshes
the jokes in this video go hard, literally
2:43 an absolutely unhinged laugh there
9:20
"or the letter T"
The letter T: 👁️_👁️
First time ever seeing this channel, this is amazing and deserves to be seen by billions
3:45 not a cube 🗣🗣🗣
1:20
they just don't want to be awkward
like they respect eachothers personal space but also don't want to stand too far away so they're just dancing back and forth cuz they didn't expect the other one to do the same :D
When you said "a binary tree for triangles" my whole core shook and i got debilitated from the inside, seeing my whole life flash upon my very eyes
i just lost and gained braincells
I wasn't expecting the mechanical engineering summary. "This is called shearing" oh like some comp sci term? No, literally just mechanical shear failure. And of course the whole Hooke's law and spring mass damper thing gave me flashbacks to Controls I
1:34 SECRET THRID OPTION: friendzone
"Air Dancer" sure is a weird way to say "Wibbly Wobbly Inflatable Arm Tube Man"
this viddeo is so good wtf
I appreciate you
@@b2stud and i appreciate your content. keep cooking
I just discovered your channel and I love your videos! I am 13 and im learning news things without decaying from boredom,I think my school sehould do this because I would actually be interested @@b2stud
I found this video oddly wholesome and reassurring. Like B2 showing in detail that my view of the universe is correct.
the loading... is awesome
Who remembers the game GISH??
VERY awesome video. Informational, and hilarious as always! Thanks for making it!
If you're interested, we took a completely separate approach to soft body physics in our game, INK INSIDE.
Basically, we baked soft body "squash & stretch" movements into fixed animations. This took a fairly complicated animation rig to pull off, but it saved us massively on performance hits as no physics calculations are done when characters are getting hit by physics objects. Instead, every animation is "pre-made" to perform as if it was a soft body all along. The animation is "canned," but we use a variation of them with minor adjustments so the action appears organic.
However, the only reason we can get away with it is because of our art style. (Cal arts / Saturday Morning cartoons).
But I figured it was worth mentioning as an option when it comes to making rigid things squash & stretch in a game :)
If I ever see anyone IRL call a Wacky Waving Inflatable Arm Flailing Tube Man an "Air-Dancer" it's immediate hands. Anyway, good video!
In Brazil, those dolls are called "bonecos de posto" or "gas station dolls" or "car repair shop dolls", which is where they are seem the most.
I actually never saw those outside of those contexts.
SIMPLESMENTE BONECÃO DE POSTO
I'm glad you added so many sorts of faces. It really added a lot of personality!! -sincerely Uel