10 mins GameDev tips - Quaternions

In this 10 mins GameDev tips we are going to explore Quaternions in an intuitive way. Don't expect deep math derivations. However after watching this video you should have a good mental picture on how they could help you dealing with rotations and orientations in your game projects. I will start by describing euler angles and their issues following by a visual example of how quaternions works (using blender). Then we are going to see different applications of them in C# using unity.
Quaternions on wikipedia: www.wikiwand.c...
Complex numbers on wikipedia: www.wikiwand.c...
3BlueOneBrown Visualizing quaternions: • Visualizing quaternion...
Quaternions for computer graphics - J.Vince: www.amazon.com...
Ken Joy lecture: • Quaternions
Unity Quaternions doc: docs.unity3d.c...
Godot Quaternions doc: docs.godotengi...

[@felipecarlin8540]

This is by far, the best explanation of quaternions on youtube. I can't believe youtube didn't recommend it to me!

[@sociamix]

Thanks :)

[@zeyadjy7229]

me too

[@larrystone654]

+1!

[@Chubzdoomer]

Came down here to say the exact same thing. No other video has broken them down as "gently" and intuitively as this one!

[@Ryan22_7]

.... and I am here to agree with everyone that this is the best explination on KZbin.

[@cullsans]

As a visual learner, the teapot example was a perfect way to teach me quaternions. Thank you for the video, you made my day!

[@ivan_3578]

Big thanks! You are the only one who said key thing about the difference between orientation and rotation!

[@jabadahut50]

Did not understand Quaternions at all until I found this video, and now I totally get it. Why no one figured out how to explain them as weights of other rotations till now is beyond me. This makes so much more sense than all the other math of how it's supposed to work.

[@JakeSidSmith]

I have read so many articles, and watched so many videos about quaternions, and nothing has helped me quite like this video. No crazy math equations or single letter/Latin variable names, just simple visual examples. Amazing stuff! There was something about the images/example at 5:00 that just suddenly made me get it. Thank you.

[@corryunedited8154]

Yeah, I think that is the closest I've come to understanding this concept.

[@mikelock6931]

Like everyone else has said... this is the best explanation of Quaternions around. The guy is a fantastic tutor. Well done!

[@CosmicComputer]

Hands down the best overview of quaternions I’ve ever seen, thank you so much.

[@lln6123]

I watched it 3 times today, to really get everything you say. After reading the chapter in "Game Engine Architectures" I was a little depressed, because it got complicated very quickly through all the detailed mathmatical examples. But I think, now I can try to read it again! You have made a great introduction, with many visual examples, great job!

[@dftpunk]

Can't believe I was struggling with quaternions and rotations for 2 weeks a month ago and have just got this video as proposed. Anyway, watch from the beginning till the end. Nice work. Thanks!

[@purplegoop1247]

the teapot explaination was really good, that alone made quaternions intuitive to understand

[@davidmurphy563]

Great video. "Euler" is pronounced "oiler" btw.

[@GoddamnSuperhero]

Other people have said it, but yes this is the most intuitive explanation of quaternions I've ever seen. Very impressed. I've used quaternions without fully understanding what any one value truly meant, knowing roughly the scaling of spheres example from 3 blue 1 brown. Appreciate the insight.

[@rockasstley7917]

I am glad that I found this video! This is really pure gold for us beginners.

[@bluemodize7718]

I really like how you explained somthing really complicated simply

[@pokoro97]

Knowing that you can multiply quaternions with vectors saved me. Thanks!

[@MerkMD]

I watched so many video try to understand Quaternion, this vid is the only one so far that make me understand.

[@man9mj]

after understanding the math of quaternions, this video cement the concept in a nice visual way. Excellent work!

[@DevranUenal]

After so many years, I finally understand it (The Teapot part helped!). Thanks!

[@klauskinnunen7404]

Finally I feel like I undestand how rotations work, thank you so much, best and clearest video I have ever seen about quaternions

[@duskjk1258]

Thanks! been working on circular motion for about a month and now I finally found the solution.

[@Kaiymu]

Purée merci. Ça fais des années que j'ai du mal à saisir les quaternions ! C'était très clair !

[@pegmen3609]

amazing..other quaternion explanations are nonsense until you watch this video....its shows how they must have been derived from a real world application..not the other way around

[@p3dee]

It's simple to understand. Thanks for a great explanation.

[@firestorm_2048]

Incredible video! Probably the simplest explanation on youtube

[@AC-mw3tz]

Finally, and thanks to your explanations, I UNDERSTAND the quaternions. Thanks, man.

[@jz9991z]

A extremely well explained video. Honestly this helped a lot

[@charlieblank3393]

I searched for basically this EXACT video for ages and NOW it pops up in my recommended and I don't even need a degree in physics? Crazy.

[@UnknownUnknown-n3z1j]

good explanation, now I know what to expect from quaternions

[@mariegrasmeier9499]

Thank you so much. Still not getting my head around it completely but have the feeling to understand much more than ever before now. Want to understand this since I tried to simulate a crane in unity and totally messed it up using Eulers 🙈

[@womeesoxkwi2689]

Wow very cool video! Quaternions makes sense now

[@thewriter3727]

I found what I was looking for at 9:14's example I like this, in the Unity answers and forum stuff, it's hard to tell where to put the code. With this example, it works basically anywhere, which is what I was wanting. I'm glad you made this video, it's really helpful. I'm going to edit this comment to see if it worked later. Have a good day! Edit: It worked! All I had to do was remove the asterisk, change the if condition to the event I wanted, and change the rotation to what I was wanting. Thank you so much for helping!

[@souravdey1227]

The best explanation of quaternions till date. Crisp and clear.

[@varunaiyar6214]

Best explanation of Quaternions on KZbin, glad I found it soon :)

[@nicks4727]

Great explanation!

[@thedebapriyakar]

I cried after watching this. Thank you.

[@erinlucassen]

Best video on quaternions ever!

[@handysandy5753]

That was an excellent explanation!

It’s hard for me to understand deeply this concept ( mainly speak French) but this is the most clear video on quaternions over KZbin. For a school project, we want to simulate the rotation of the moon around the Earth by using Python, quaternions and maybe Blender but idk if it’s gonna work. Do you think it could be achievable?

[@gamedever]

You definitely can use Unity. Yes I replied one year late. Sorry about that.

[@zeyadjy7229]

I really lost the passion for game dev because I don't understand how quaternions work and how to use them, thanks a lot I hope u do more examples on quaternions use cases in unity

[@denisgoodman4492]

Very Good explanation, But in last slide will be good to add that qB*qA*VectorA qA*qB*VectorA AND qB*qA*VectorA that means - the VectorA rotate on qA and after rotate on qB PS> !!! The relation between length Video and Volume of information is the Best (... and very good links *3BlueOneBrown* )

[@crogersdev]

Great explanation! Thank you so much. If you're in France, next time I go there I owe you a chilled Orangina.

[@aru1814]

I have two irrelevant questions: 1. What is the name of the bgm song? 2. Where I can find the open source of arrow prefab? Btw, thank you very much for the easy explanation!

[@xthene]

the euler rotation system is based on a parenting structure , e.g. X > y > z ....this is the part i don't understand: why a child - parent structure is necessary in euler system? why can't the 3 axes be able to rotate independently in euler system? what's the catch?

[@HateSonneillon]

Definitely the best explanation I have seen by far.

[@alexanderheim9690]

3Blue1Browns interactive videos state that quaternion rotation is double covered. Which would mean that your statement at 5:40 is wrong.

[@angeldude101]

You are correct. There are two ways to reach any given orientation: clockwise or counterclockwise. Ultimately there's not really a difference when just doing the full rotation, but the difference matters a lot when interpolating, since the choice of target quaternion determines whether you take the short route or the long route. It's also important in quantum mechanics since as strange as spin-1/2 particles are claimed to be, quaternions themselves are also effectively spin-1/2 themselves.

[@nofacee94]

Finally, a clear explanation.

[@jaimetheone9150]

The last one, the quaternion multiplication seems to be the answer to a camera rotating around an object or a point!

[@noumankhan167]

Amazing Explanation man , you cleared some of my doubts that I had for months

[@moheyaldeenalmardiny82]

That's something I really needed thanks a lot man

[@bertani6134]

This is too important man! Thanks for sharing!!!

[@AlexandreCoulonOldChannel]

Merci infiniment, je pensait pas que j'allais si bien comprendre, comme quoi quand on à le bon prof c'est beaucoup plus facile^^

[@31618doremi]

best explanation ever!

[@theman7050]

Thank you very m7ch for making sense and not making just another rocket science video about euler and quart. I wonder why other tubers lack this basic IQ that If you are "teaching" something technical on youtube, you have to begin from the ground up and treat your audience like 5 year olds and I am sure a majority of viewers are changing profession and dont have scientific background. Goshh

[@jimbotht1091]

Mais c'est que c'est très intéressant tout ça, merci, j'en redemande

[@DevMarco-]

Coming from Euler rotation like many others I guess the hardest part to get in my head is that xyz are not representing an axis. If quaternions would use abcd instead it might be easier to grasp from the start.

[@DubZenStep]

Best explanation out there. Thank you man!

[@jacobkamen9265]

Great video! Thank you

[@mz00956]

Thank you so much. I never understood them until now.😅

[@sevazakharenko8176]

Great explanation!!

[@허언증완치자]

I wonder that, When match two random coordinate system, it is needed to maximum two normal rotation with two axis vector. but some quaternion (especially multiplication of two rotation quaternion made from each axis/angle) can do match them. I think and wonder combined quaternion has ability that apply two rotation to vector in parallel. it is like spinning top in axis is rotated in axis.

[@ssojyeti2]

great video. now, time to put this knowledge to work!

[@nattherman7321]

ima have to save this one, thanks

[@chenni8759]

Amazing! Very well explained, thank you so much!

[@akshay3538]

this is very well explained, Thank you

[@sociamix]

Thx :)

[@SwayamVaza-qr8vs]

Wow that was really cool 👍

[@ridespirals]

great video, thanks a lot. and maybe you know this already, but Euler is pronounced "oiler"/"oy-ler" not "yooler"

[@legendfpv]

It's an accent.

[@alexanderwinn9407]

@@legendfpv It's a common mispronunciation, among people of all accents. "Euler" looks like it should be "yoo-ler," similar to "Ferris Bueller." But it's actually "oiler," like "someone who oils."

[@emanueol]

great video. Im wondering how to code flight simulator where player can Pitch (rotation on X), can Roll (rotation on Z) and can also Yawn (rotation on Y) .. imagining XY as screen axis and Z axis perpendicular to screen). Imagine if player simultaneous press key to Pitchdown (10 deg) and also press key to roll (30 deg), my understanding is to have simple a orientation quaternion (initially player looking into z with no roll and no yawn so initial Orientation = Quaternion Euler( 0,0,0); now my struggle is how to represent the 2 movements since order maters right ? thanks so much

[@AndresJesse]

Excellent! Clear as crystal! thanks!

[@Michael-sb1tt]

I noticed during your inverse function section the arrow was rotating about the bottom point. How do you get the object to rotate about its bottom point instead of its center?

[@pleison111]

This is pur gold!!!

[@ahmedaghadi8281]

4:03 so what if we always rotate with respect to x,y,z axis and not rotate with respect to object itself.

[@sundarakrishnann8242]

Amazing video! Thank you so much!

[@agastyavalisetty8620]

a good video always comes after i complete a project on that topic, your video would have saved me at least 10 daysand also all the frustration, that how da frik was unity so smooth and not arduino (arduino was stoopid, I still don't know the solution, it works tho)

[@hafizuddinmohdlowhim8426]

You are a genius!

[@dylantb619]

This is extremely helpful!

[@lukay6230]

other tutorials were overwhelming me with 4th dimension, but based on this, I think its simply vector XYZ and W is resting vector "importance"? I may not undertsand it well, but I understand it more after this video

[@angeldude101]

Pretty much. The w component is a weighted scalar 1, which just says how much to _not_ rotate. 4 dimensional visualization is absolutely not required. Once you accept that quaternions are fundamentally 3D objects despite having 4 components, then you can begin to understand how they relate to complex numbers as well as other hypercomplex systems (like the dual-quaternions, which have 8 components, but still ultimately represent 3D rotations in addition to translations). In the complex number a + bi, a is just how much to not rotate, and b is how much to rotate around the origin. It's not really a vector at all much like how a quaternion isn't really a 4D vector.

[@binhql]

Exellent video!

[@josephmorales652]

Incredible video!

[@ctobi707]

THANK YOU THANK YOU THANK YOU great video i finally understand this witchcraft

[@lucasloisance9566]

Merci beaucoup, tu as illuminé mon esprit :)

[@adamabbott2014]

Hi, i'm confusing about transform.postion = quaternion.euler(0,90,0)*diretion. how is it working

[@CaCriGuz]

Thanks mate!

[@FuranA7x]

Thanks!

[@RemiStorms]

Excelent video on Quaternions !!!

[@sheikhg1900w]

In short. Thank You very much.

[@enjoybro4515]

thanks so much it help me a lot

[@Jono1982]

extremely useful please make more tutorials

[@JoostKiens]

Really good explanation! 🙏

[@oneRella]

What I don't understand about gimbal lock: Why don't we just fix all rings to each other like a ball and rotate the whole array?

[@fly7188]

that is gimbal lock you effectively only have one axis of rotation at that point instead of 3

[@josepgc1183]

I owe you my life

[@biny_749]

merci beaucoup sociamix 👌👌

[@luckyyo7287]

good course！thanks

[@f3rn4n2x3str3ll4]

BEST! Thanks!

[@alexmattyou]

Thankyou for the video, I know that you're Blender and Panda3d user by your models

[@tejasbele1456]

Thank you so much

[@graphic-nations]

thank you its amazing

[@qbytez5006]

Thank you!

[@graphic-nations]

amazing thank you

[@guyschill2059]

I love you bro

[@runnow2655]

I don't get what you mean by normalizing to not show 4D movement, you know quaternions don't describe 4d movement right? for that, you have to use octonions, a real number and e1, e2, e3, e4, e5, e6, and e7. You need x^n-1 numbers to describe n dimensional space

[@runnow2655]

also quaternions are usually described as a+bi+cj+dk where a, b, c, and d are intigers and i^2=j^2=k^2=i*j*k=-1, they aren't typically described with WXYZ as far as I'm aware, but this may be a math community and programming community disconnect where WXYZ is the codding equivilant of r+i+j+k

[@Toothless2]

@@runnow2655 If you dont normalize them then it will scale the vector when you multiply