I’d like to know the difference between the two?
From the outside, they look like they function the same, and I find ik rig easier to setup than control rig.
Anyone has any idea as to why?
Thanks,
3 Likes
I’m asking myself the same question. IK Rig is obviously required for the IK retargeter. The documentation doesn’t say anything about how both systems might work together.
2 Likes
Greetings @Kinos141 !
This topic has been moved from Community - Community & Industry Discussion to Character & Animation. I added the optional tag “Rigging” for you as well.
When posting, please review the categories to ensure your topic is posted in the most relevant space. 
'- Your Friendly Neighborhood Moderator
2 Likes
I’m here to refresh the question.
From my side, I’d like to add that lyra only made me more confused about it when I started reading about those 2.
and here is why:
I wanted to do full leg IK on my own in docs there are simple descriptions of two
IK Rig
“Retarget and procedurally adjust animations using IK Rig and Retargeting tools”
Control Rig
“Rig and Animate characters in real-time using Control Rig”
After reading just this my first guess would be to continue with IKRig but in lyra whole leg IK is done in Control Rig. Is there a specific reason behind this or did epic just wanted to show off some features?
OK so a control rig is a type of exoskeleton that can be mapped over a skeleton that does not use the required naming convention. Usually using a relationship constraint that will allow for “any and all” rigs that does not use the preferred naming convention to be used. A good example of practical use would be Motionbuilders control rig as to how it can be set up.
At the moment Epic’s control rig, as an opinion, is yet fully completed as to intended design in Unreal 5 except for possibly animating “some” keyframes but is rather limited as to what it could do as to removing the need to retarget Epic animations to a custom rig, such as Genesis 3/8, as well converting ready to use BP’s.
IK or Inverse Kinetics is an element that could be added to a control rig or used standalone as via 2 bone IK where the end effector can be attached to an object that drives the attached joints in an FK type direction.
Over all I would have to say that Epic is following a path towards full body IK which has been around for years so yeah IK would be required
3 Likes
i think this is a awful design，control rig cannot use ik rig，so if you want to keyframe animation，you need to set ik in control rig repeatly
2 Likes
So like Ik rig would be for pre-made animation and control rig would be for realtime keyframe animation?
1 Like
That’s the impression I’m getting too, although I am a neophyte with UE.
It looks like “control rig” is meant to be an animator’s aid, allowing an animator to use the rig within sequencer to create animation assets.
Whereas “IK rig” is meant to adjust animations in-game, such as keeping the feet planted on the ground or having a hand reach out to something in the environment.
As I understand it, IK Rig is also used to perform Retargetting between rigs. You setup one IK Rig for each character, then use a IK Retargeter to match the poses between them, and then you can transfer animations.
With UE5.4, they’re planning to introduce Modular Rigging. It’s great and I can’t wait to play with it, but honestly, there’s a massive opportunity being missed here.
Instead, they could use the setup done with the IK Rig (labeling limbs, IK Goals, etc.) to generate a Control Rig from it. Clavicle, arms, head, tails, legs, spine, all of it could be generated in the same way, just by using the labels created in the IK Rig creation process.
We could even leverage this logic to create the “Modularity” features we want! Say, you want Arms to be created with IK as the default, or you want the whole body to use FBIK instead, or perhaps add up-vectors for the FK tail controls.
Let me create a Control Rig from a given IK Rig.
If we have the ability to turn this into a Feature Request ticket, that would get my vote.
1 Like
Well there is no such thing as an IK rig so to speak but rather a rig that has an IK solution applied A typical control rig would be a combination of different solutions that includes the ability to switch from FK to IK. High end animation apps like Motionbuilder, 3ds Max, and Maya have the abilities to create control rigs that offers function and features that offer a broad range of scripted options.
As I see it the current state of the UE control rig offers the building blocks to build the framework that will add flexibility of being able to use stock Unreal animations on any custom based rig with out having to retarget animations.
It’s not something new but has been around for a while, like in Assassin Creed 2 which uses full body IK, where the IK can pull the body towards a target.
Unreal Engine’s IK Rig is used for Motion Retargeting from one Skeleton onto another (helpful if the target character’s proportions are wildly different to the source). I have yet to find a way to use the IK Rig in the Sequencer.
Control Rig can be used for a lot more, specifically in the Sequencer to perform Character Animation.
Control Rig takes a good while to setup compared to an IK Rig. My complaint/request is the IK Rig setup could be used to create a new Control Rig on the character in a fraction of the time, while also being a much friendlier setup for beginning artists.