Hi everyone, I’ve been trying to use the new modular control rig features to rig my character. I’m using the UE5 skeleton.
It mostly works but the issue run into is that when I switch my arms to IK, the elbow seems to break and bend strangley. Seems that the IK function is somehow incorrect.
did you ever solve, I have a similar problem within unreal 5.4.3, arm module is causing my IK arm to flip, i have tried changing primary bone axis, direction, nothing seems to fix this issue
It feels like even in 5.4.4 with the pole vector fix, the fk/ik solve (which is shared for arms and legs) is not congruent. This is noticeable when you drop the leg module (by default in IK mode) into the socket and the leg pops from the bind pose. For the arms you don’t see it because it’s setup in FK initially and once you switch to IK it’s using an incorrect approximation of the FK representation. You can take a look at Manny’s forward and backsolve for arms and legs to jimmy rig your own modules but even in my current attempts at this it’s still not perfect. It is solving closer than the default modules though. I think there may be other underlying bugs that need to be ironed out.
Same
One side of arm is always faulty
Anyone more?
Just a follow up question as I was rewriting my own fixes on top of the modular rigs, from which I had to do my own fixes around fixing up the arms. Are you guys using the Auto Determine Axis flag? If so it will ignore your primary and secondary axis in the IKTwoBone function input. If you want to use your own defined axis you’ll need to turn this off.
Assuming you are following Manny/MetaHuman standards on your rig, you’ll want to use:
Primary: 1,0,0
Secondary: 0, -1, 0
Primary: -1,0,0
Secondary: 0,1,0
I ended up writing a better solution for when Auto Determine Axis using local transforms instead.
