FK and IK Explained - Which One to Use and When?

What is Inverse Kinematics? How and why to use it? What are the differences between FK and IK. You can find all the answers in this short explainer video.
Forward and inverse kinematics are essential part of every animation and every animator should understand it.
The rig I explain it on was done in 3ds Max CAT.
3ds Max CAT (Character Animation Toolkit) is an animation system inside Max that offers a lot of useful features.
If you are interested in CAT and why is it (in my opinion) better then biped or regular max bones, be sure to subscribe to the channel or watch other videos and tutorials I have already posted.
You can find Barry character rig here for free: www.miloscerny.com/download-b...
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[@varudulc]

7 mins ago i had no effin clue what FK and IK meant, uve just made all my tears meaningless now thank yOU

[@loop5720]

noiceu!

[@J_A_C023]

🤣

[@freelance3dartist979]

You were a big help, I finally had the light bulb moment from your explanation! Thank you for taking the time to help everyone.

i love that you make us realize the greatness of cat

[@mazenezou]

While Autodesk doing the opposite

[@haticeleylaa]

I was taking classes about six months on Maya, but never understood what exactly IK/FK is. After watching your video, finally I got it. Thank you so much, it was so helpful and illustrative!

[@gabrieldomingues6322]

one of the best tutorial focused youtube channels i ever found, well done, great and simple presentation and examples, you won a sub on patreon, totally deserved

[@KITATUS]

Fantastic video - Great style, simply taught and entertaining! Really nice stuff. Can't wait to see what you come up with in the future!

[@melissaobrien8139]

Omg THANK YOU. Finding anything related to this in 3ds Max is unusually hard but this was very helpful!

[@randomguy4738]

"i guess you're not here because of the math." YES I AM -_-

[@dishakhurana6739]

me too 😂😂😂😂i love maths too

[@Madlion]

your videos are amazing, I'm an Unreal developer but is now learning rigging and animation to understand the whole pipeline better and your videos are great for me who only knows 3dsmax

[@krisluz5510]

Searched up for IK vs FK. This is by far the most concise video, insta subbed

[@diomiziofattorelli6609]

You are the best teacher in animation. Very talented and very clear explanations. Wish you the best!

[@junimeme5626]

You can't get a better tutorial than this. Amazing

[@DreamSyndromee]

I just got here from my animation class in uni and I understood better in these 7 minutes than in those other 40 lmao. Thanks a bunch!!

[@Dangermouse3435]

Never seen a better explanation. Thank you very much

[@theanimatedflame]

Really informative video! Thanks for this.

[@supersangwoo3342]

Very nice tutorial for 3DS MAX CAT !!!. Thank you~

[@jakubkotwica4034]

Milos I just love your narration :)

[@polygraphliedetector]

Thank you for sharing, this information was very useful when making decisions about animating.

[@AbbasKhan-dk5sb]

Amazing explaination !! You rock man 🤘🏻

[@prof_werneck]

Excellent demonstration! Thank you!

[@ajeet1994]

this video cleared my confusions and also taught me very useful things.

[@RenzoFlame]

This was very helpful, thank you. I was worried that there was a "correct answer" about using one or the other; or that once you start animating, you were just stuck with the one you started it with. It was good to see in action that you can easily change between them at will. Just a matter of find out how to do it with each program

[@cristianjuarez1086]

the correct answer is whichever one you need

[@sandeepadikkumbura]

Very well explained. Thanks for the tutorial

[@shadowstart2oo4]

Excellent all the tutorials, very useful, greetings.

[@rahuldeshpande9997]

IK is super awesome, Thanks for providing the above explanation and demonstration

[@andreshernandezperez8762]

This video is the answer that i have been looking for, thank you

[@ninny65]

Fantastic video mate, understood everything with that accent of yours

[@Gregasaurus]

killer video yet again.

[@soundfxlab2837]

Thanks a lot, i agree with Paulo. If you create a full CAT Animation with all the principles that you know, you will create THE BIBLE OF CAT RIGGING in youtube, because there isn't many good tutorials or info about rigging, skinning and animating in Max.

[@Jiry_XD]

Thanks a lot 😁, you deserve a lot more subscribers

[@inkastoyanova7826]

very well explained

[@alaahesham250]

Very helpful and clear tutorial

[@nijatIbrahimli]

Thank your amazing tutorial :)

[@To-mos]

A 2 bone IK solver most of the time uses the law of cosines to complete the triangle, however anything more than that has to utilize a jacobian matrix inverse to get closer and closer to the target position. The latter is what most robots use as a closed loop control system for feedback adjustments. The more you know :D

[@joshthebrawler]

Sorry to reply, but that's really cool! This helps me understand how the arms try to move so I can adjust and work accordingly, so thank you!

[@matyasiszlay5532]

perfect explanation!

[@DepthAudio]

Great explanation!

[@QuyenNguyen-xm3xr]

so good video tutorial, thanks so much

[@jomoswagos]

thx, nice and short!

[@Cirelectric]

great videos, thank you!

[@g-tech3113]

great video, thanks so much!

[@paolaotero9125]

Excellent! Thank you!

[@MultiBRETTER]

nice! just created my first IK platform yesterday and I was wondering what FK/IK means. Got no matches in Max docs somehow. Very helpful tut! THX

[@AlexUdilov]

briliant tutorial man!!!

[@faktorial2]

Great video!

[@user-bi3xn8dj7y]

So could you do a mix of both ik for the shoulder and elbow and fk for the fingers...fully asking questions before a video finishes explaining things but this has all got me excited haha !

[@VlogrBlogr]

oh WOW. Thank you for this.

[@MultiBRETTER]

still great explanation. I forgot about FK&IK within 3 years ;D

[@montasserfaidi1966]

Good job 😍

[@chunld]

Thank you for those great tutorials,It's very useful! I have a question about Foot Ik platform, I hope it's flatten but IK/Fk switch will change it's pose especilly digit (toe).Thank you~

[@jabbarnendra563]

thank you for the explanation!

[@i_am_a_real_cat1443]

Amazing channel!!!

[@citrusblast4372]

That was a realllly good video

[@FarmingWithAsifBashir]

Useful and informative. Thanks 👍😍😘💝❤️🔥😎

[@nounonarabara5702]

07 mnits = 7 months or years good tutorial and thank for the subtitles

[@ZeeshanAcademy]

Wonderfull explanation and great presentation video.. very usefull .. thanks

[@szubkaMuffin]

Great set of tutorials! Although I have to say, the music you chose to put in the background literally put me to sleep yesterday evening, soooo maybe next time go for something more energetic?

[@felipemaximo5021]

Gracias excelente video !

[@rkgamesstudio6977]

This helped me a lot

[@riky070483]

I'm Brazilian and I learned with you

[@mustafashamsi6426]

this animation taught me more than my Kinematics of Machines class

[@dremovremen1764]

Thanks for the clarification. Btw, what's the music is playing in the video?

[@MrJonh95]

nice video! subbed!

[@LouiseChib]

is the feature to swithc from FK to IK, vice versa available in Maya and Motionbuilder?

[@haryigit]

How can I stretch bones using CAT? I want my character's arms and torso to get longer when needed.

[@gamedevmode]

Thank you so much!

[@MohamedNopy]

I can't say anything but thank you so much for these 7 minutes that have a comprehensive course.awesome

[@lifesymbiont5769]

What is the music used in the background?

[@gerritschwalbe9079]

May i use some short parts from the video for a presentation in my university?

[@armeniouz3D]

Subscribed!

[@rahuldeshpande9997]

Some definitions: Effector: which is the part of the skeleton that interacts with the environment, such as a hand or a foot

[@jayjaygolden5123]

how do i add an IK controller to a manual cat bone chain? (not a premade leg/arm/whatever)

[@maiax3i]

nice you saved my ass, pretty well done explained

[@youchannel8454]

Good way to explain

[@g-dev7336]

thank you ❤

[@anonymoussloth6687]

What software do u use to do the animation at 1:50?

[@unreal-forms]

is there an easy way to set the bones zero? if "freeze transformation" doesnt work! then what's the solution? it's the only thing i hate about CAT

[@davav2688]

Amazing

[@jaxsykeses2059]

You making cool videos fam

[@jasoncatlyn7331]

Thanks!

[@armanchahal1]

thanks buddy

[@radenzito]

I can't believe this high quality content exist, it's hard to find nice CAT tutorials like this, well I they are unique, nothing comparable with that!!!! keep going, i'm going to support you on patreon, you deserve it

[@Samuraicbl]

Fantastic! You should do a full CAT animation tutorial from scratch!!!

[@ZackMathissa]

I eat cats

hi Milos, is it a way to create a ik target for the head bone? i need to make a dinosaur bite something and his teeth atacched to the surface, for now i havent come with a good solution, i have tried of doing an ik target or a link constraint to the head but it doesnt work, i can only do link constraints for the leg plataforms so far

i found the solution, just using link constraint, the problem was that when aplied the bone would fly to some part of the scene, all i have to do is bring it back

[@tuhinzahid7142]

Thanks a lot...

[@crispincardoz8934]

thanks man

[@kimsanovomadbek2713]

Thanks

[@Ponlets]

can you teach how to do this in blender

[@manukureaboagye7405]

Lol! we are not here for the maths! Love your approach

[@deepelements]

Great tutorials! Any chance you can make a tutorial on how to use cat in Unreal 4 or cryengine. CAT looks amazing but i'm worried about using it for my game animations because of the issues with rootmotion.

Thank You. I will get to that eventually. What issues are you referring to by the way?

[@farizaziz]

awesome

[@OnixSnipz]

In Maya, when you switch FK to IK, the controllers are at the same place, you don't have to click the Move IK Target

[@unreal-forms]

and how to set limits for those bones stretching?

[@samchaos1588]

Ibrahim Bitam by using set driven key

[@johnleo1756]

One thing that was not clear to me, is the relationship between IK/FK and animation layers. I thought you could set one layer to FK only and another to IK only, but it seems not so...

[@digital_ferret7263]

You created animation to make a video to teach future animators to make videos

[@dinhos.5356]

Muito bom!!

[@buyinggf50gp10]

This information will come in handy when I play koikatsu.

[@user-di9cs1xo2m]

thanker yer

[@tobiaswinter5495]

1:24 Yes, that's why I'm here, haha

[@harsh9558]

Thx

[@timomaessen]

Haha, lifesaver