Problem with updating a bone transform in 5.5.2 after updating the project from 5.4

[Vyper284]

Edit: I found the issue and posted solution in next comment.

So when I moved my project over from 5.4 to 5.5.2, I have this issue where I can’t get the IK rig working anymore. I’m basically trying to set the hand bones to match where the motion controller is (it’s a VR game). I was using an IK rig, but to keep things simple I’ve set it up to do what should be a simple transform of the bone to get it in the same location as the motion controller.

This is my setup:

So this is in the AnimBP Event Graph update (I’ll switch to use thread safe when it’s all working). It’s just setting the transform from an object on the VRPawn:

Here I’m passing that transform into the control rig, nothing special:

And finally, in the control rig, I convert it from world to global rig space and set the bone transform:

This works entirely as expected in my 5.4 project, but in 5.5.2, the bone transform just isn’t being set. I hit play, I move the correct object around, I’ve confirmed that the LeftHandTransform variable is being updated when that object is moving, but the bone is just staying put.

If I print out the transform being used within the control rig, it’s never being updated, just staying at the default value.

I thought maybe a control rig issue, so I tried without it, just setting the bone position in the animation graph:

I’m not converting the location to component space or anything, but just for testing purposes, this should be moving the bone when that transform updates right? I can disconnect the transform and put in values myself and they work fine, but when I try to use that transform, it’s just not working. I enable watching the variable and it shows that it’s changing (and should be some large value causing the bone to move way out of place), but the bone is staying put.

If I start a new project and do a quick setup of the same thing, it works fine, so what’s going wrong here? I even created a new anim blueprint and control rig and I just can’t get it to work. So some kind of bug when updating the project to 5.5.2 I guess, but I don’t know how to fix it.

Any tips for fixing or debugging this kind of issue?

[Vyper284]

Did some more messing around and found that the issue is related to the Skeletal Mesh in the VRPawn that was inherited from the Character class. I noticed that I had the same issue for an enemy too. If I add a new mesh it works fine. I also found that if I change the Component Class of the buggy skeletal mesh to something else and then back again, it fixed the issue, so just some weird bug as I thought.