Control Rig quick start guide! Basics, IK/FK spine, IK/FK arm & in-game leg IK!

Project files are available for free on my Patreon: / ghislaingir
Twitter: / ghislaingir
Mastodon: @[e-mail]
UE's Control Rig Doc: docs.unrealengine.com/5.2/en-...
0:00 Intro
1:46 Quick Start Guide - Blender Setup
2:18 Quick Start Guide - Basics
4:14 Quick Start Guide - Construction Event
4:44 Quick Start Guide - CE - Import Skeleton
4:57 Quick Start Guide - CE - First Hierarchy
8:30 Quick Start Guide - Forward Solver
9:55 Quick Start Guide - Hierarchy Importance
10:18 Quick Start Guide - CE - Reparenting
10:38 Quick Start Guide - Backward Solver
11:35 Quick Start Guide - Cyclic Dependencies
12:53 Quick Start Guide - Separate Hierarchy
13:14 Quick Start Guide - Export & Edit Animation
13:55 Quick Start Guide - FK Limitations
15:03 IK/FK Spine - Construction Event
17:06 IK/FK Spine - Forward Solver
21:12 IK/FK Spine - Backward Solver
22:17 IK/FK Arm - Construction Event
24:15 IK/FK Arm - Forward Solver
26:57 In-Game IK Leg - Using Different Rigs
27:35 In-Game IK Leg - Forward Solver
28:06 In-Game IK Leg - Offset Principle
29:22 In-Game IK Leg - Capsule Offset
30:00 In-Game IK Leg - Missing IK Bones
30:40 In-Game IK Leg - Anim BP
31:00 Outro
Hey! I didn't necessarily plan to make a video on Control Rig but here's one! I wanted to give Control Rig a fair try to see if it'd fit the requirements for a personal project of mine, and upon reading the documentation, exploring demo content released by Epic and watching tons of KZbin tutorials, I realized I may have something to bring to the table after all.
Thus, in this video, I first make a fast introduction to Control Rig, then I do a breakdown of a complex IK/FK spine, a switchable IK/FK arm and an in-game leg IK setup.
I tried to be as descriptive as possible but some rigs are quite complex, so be prepared. Hopefully this video helps in some way in your own Control Rig journey :)
Thanks for watching and thanks for the support! Cheers.

[@Rydn]

I'm doing a masters in UE development. Still, I learn WAY more from your videos. You enter a topic nose down, and force us to learn a lot of interconnected features of whatever you are interested in. ❤ Your content! I'll 100% support your patreon next month!

[@ghislaingirardot]

Thanks, that means a lot! I try my best to bring something new to the table and dive deeper than most tutorials out there. I don't always succeed in making sense but oh well :D Thanks for your feedback & support, much appreciated!

[@Shrooblord]

Even "throwaway" lines like the 2cm offset coming from the Character Movement Component when you're doing the Leg IK Offset near the end -- stuff like that I would've never thought to chase down but now I have arrived at some deeper understanding of how the systems interact. Great stuff!!

[@RogerHazelwood]

super helpfull for me, thanks!

[@BryanHoward]

Great tutorial! Coming from Maya rigging, Control Rig looks great with things such as backwards solve. Very much different paradigm in comparison to maya. With the construction event it’s kinda like the way you’d build a python auto rigging script in maya. IK/FK switching rigs in Maya are generally done with a 3rd joint chain that is part of the main joint chain of the rig. The IK and FK joint chains act as weighted targets for the blend chain usually as a float value 0-1 and that value drives orient constraints of the blend joints to the IK and FK joint chains. Animators like this because they can animate the blend if for example a character needs to switch from a more natural FK arm movement to an IK pickup a glass off the table movement. It’s interesting how in Control Rig you don’t have to do such things because you can implement it a backwards solve. Similar things can be done in maya but usually feel like hacks involving python to calculate the new positions. Certainly not as clean as Control Rig. The movement in IK/FK switching looks like it either due to the node calculating the plane for the pole vector or possibly there is a small offset on one of the controls in the initial value. My gut feeling is it’s something to do with that node. Could be checked by isolating that node and verifying that it's positioning the output onto the plane for the pole vector. Honestly if it's a bug it's probably not too difficult to create a function and calculate the trig + offset value for the pole vector position.

[@ghislaingirardot]

Ty! Yep I do quite a bit of rigging here and there in Blender and I'm used to the old school approach as well. One chain for FK, one for IK, one for Blend. Then one more for stretch/tweaks and so on. It definitely feels a lot more clean in Control Rig. But then it has its downsides. In the end I kinda prefer rigging in Blender still, and I definitely prefer to animate in Blender, although UE has cool space switching features and whatnot already. The pole bug, I dunno, I haven't investigated it at all since :D Ty for the feedback

[@francoiscaillaud5275]

Merci Ghislain ! ça va super vite et il faut s'accrocher mais c'est très intéressant et utile ! Contrairement à d'autres vidéos YT, tu maitrises ton sujet à la perfection

[@ghislaingirardot]

Merci pour ton retour! J'ai tendance à faire des montages assez denses oui, dsl. Surtout celui ci, c'est pas mon meilleur 😅

[@StrayVertex]

Super cool! ❤

[@ghislaingirardot]

Thanks!

[@abdoulraoufgambo]

très bon contenu !

[@hotsauce7124]

Can you please do a tutorial how Bungie man does the squash and stretch with morph targets?

[@VictorMartinez-cu9gj]

I am currently trying build a control right with an ik/fk switch. This was the only video in all of youtube that had an explanation on how to build it. Unfortunately, it was still very confusing. You quickly thumbed through the most important part of the video and just showed the nodes with going into more detail about how to make it. I am not super well versed in the process of building control rigs so that might be my issue. Additionally, I am using a different method to make the controls so if i attempted to follow along i would have had to restart from scratch.

[@hotsauce7124]

Hello in UE5 control Rig, have you created an IK leg with a reverse foot setup from a Blender 4 Rigify Rig?

[@ghislaingirardot]

Hello! Nop

[@hotsauce7124]

If a collection of controls are in an array, is there a way to scale all the controls at once to a specific scale? Instead of scaling the controls one by one?

[@ghislaingirardot]

No idea!

[@naza0777]

im not sure but i think the double transform its because of keep adding the same element to variables, in control rig every global variable should be rested in the construction nod to prevent that.

[@ghislaingirardot]

I'm not sure I'm following. I only set global variables once in the construction event.

[@naza0777]

everytime you compile the variable keep adding the same elements to the variable and then calculate twice everything using it, it needs to be cleared in the construction nod

[@ghislaingirardot]

@@naza0777I don't add to the array though. It's set from a local array output from a function. That local array's size is fixed to 4 entries and I use SetAt to update its elements, so both local & global array never grow and don't need to be cleared.

[@hotsauce7124]

Is there a way to connect a morph target to UE5 Control Rig?

[@ghislaingirardot]

No idea!

[@Kuuribro]

Yes, you can. Check the "Content Examples" pack of assets UE5 gives out as demos for a lot of things.

[@hotsauce7124]

Sorry, the Content Examples are very hard to understand. There are a lot of wires and functions with variables; too difficult to understand @@Kuuribro

[@Kuuribro]

Can you please point me to something that explains what that "Make Absolute" node at 21:07 does? I know you said you'd have to make a whole course on space switching to explain that, so I won't ask you to make that. But I am going insane trying to understand just what that node does and I have found *nothing* that explains it I have absolutely 0 concept why anything labelled "Absolute" would have a PARENT input that changes its math. I don't... get it, and it's used in a ton of Control Rig examples, and I have to understand it to modify or pick apart any of them.

[@ghislaingirardot]

You might want to have a look at my 'stylized grass course' video. It sounds like it has nothing to do with control rig, but I made quite an effort to explain world/local/absolute space transforms, so that might help. Essentially it's just a way to tweak a location/rotation/scale so that the reference point/origin is no longer X but Y. Say the world origin, to the origin of a bone, or the other way around. It lets you do maths and move pivot points around, pretty much. Hard to explain

[@Kuuribro]

@@ghislaingirardot But that's what "Make Relative" is for, isnt it? Do transform stuff in relation to something else. "Make Absolute" should have an *absolute* output, not something that can be modified by putting in a parent, thats the hurdle where I get stuck. I've even tried making test cases with chains or joints, individual points, various parenting, axis markers on everything, and it just doesnt make sense. I can't parse the output it's giving me, even using simple blocks in space of 10 units. Like, I understand what World and Local spaces are, I've done some shader work with these things, but this converting transform math is breaking my head. Also, I'm trying to watch that video, and it's not applying to this. I understand world and local *positions*, world and local space, but the way Absolute is used here is how I understand it. Absolute World Space, absolute = ultimate, the world coordinates, regardless any other objects. Camera space stuff gets mathed on top of that. Plus you're applying everything on a use case that modifies pivots that have all been set at 000 to start. That's not the case in this rigging, which also has a bunch of stuff rotated in various ways, relative to its own initial value and to other objects. I'm sorry but this grass shader video isn't filling in what I need to make sense of the Make Absolute node in Control Rig here. Do you know of any other resources that break it down?

[@ghislaingirardot]

@@Kuuribro Yeah well, control rig is confusing to say the least. Especially considering what control rig considers as 'local space' is technically 'parent space' but that's another thing entirely... Sadly, no I don't have other resources that explains it. But absolute space has to be based on a parent, the way I see it, it does the inverse of what make relative does. See if using draw debug functions in control rig can help you figure out what it does. That's as much as I can help :D best of luck!

[@medmel2160]

bonjour.

[@ghislaingirardot]

Bonjour!

[@shingAMarie]

Can you redo this tutorial going slower and explaining each thing you do. I feel like when you add things you just go way too fast and the mouse moves fast and it makes it hard to follow.

[@ghislaingirardot]

This is the wrong video to watch if you want an introduction to control rig :) There are plenty of videos showcasing the basics of control rig in great details, there's no point for me to do one more. This video is meant to shed some light on some more, undocumented, adanced examples. Thanks for watching & your feedback!

[@shingAMarie]

@@ghislaingirardot 👍🤭

[@robertbin28]

this is not basic its very advance level and the process is very fast

[@ghislaingirardot]

Sry about that, not my best one :)

[@robertbin28]

@@ghislaingirardotno need to be sorry about anything for noobs like me i should understand the basics than follow your tutorial