After retargeting animation to a character, whenever I enable Feet IK in the ABP, the character is lifted off the ground, legs bend, and tilted forward as shown in the character on the left.
If Feet IK is disabled in the ABP, the character behaves as intended as shown in the character on the right.
I’ve isolated the issue through connecting and disconnecting nodes in the Feet IK control rig, and identified Full Body IK as the culprit.
So long as the nodes are connected to Full Body IK, the character will automatically lifted off the ground, even if it is the only node connected to Forward Solver.
Was wondering what is the issue causing this and if anyone can shed some light on this would be awesome.
I’ve also tried a character with heel - Paragon Countess - and the feet ik works without any issue with the same abp and feet ik control rig. Other flat shoe characters has no such issue as well, only this character.
The initial “heels" suggestions is right on spot. You can tell by the fact it leans forward.
Simply cut the chain setup of the IK node down a notch. And remove the toe bits/adjustments if any are present in the IK system.
Or - export the character and replace its skeleton to the stock ue4 one. Then delete the skeleton and re-import in engine creating a new one. It should then just work…
Not sure if this additional info could help identify the root cause.
Meanwhile, I’m communicated with the asset creator and he’s looking for a solution to address this, at the same time I’m also looking for a solution on my end. But the weird thing is this - in the creator demo level, his own feet IK setup works without any issue and the setup control rig is almost identical to the ACF plugin, I tried to copied it, but result is always the same.
At a loss as to why it’s doing exactly this.
Would need more info.
Rule of thumb - regular IK systems do not involve heeled shoes. When you add heels, you need to modify the system to account for them.
This is because you normally adjust Ik to handle the heel/toe transition gracefully based on an anim-curve to turn it off (for it to walk and what not).
So the tip of the foot bone (ball of the feet) is calculated and the angles adjusted.
When you deal with heels, you are essentially forcing the character to walk only on the ball/last bone. And the ankle position is mostly locked (well depends on heel length but over 3 inch, I’d say just lock it in place).
So for IK to work, you have to change how it works and where the calculation happens.
It’s not at the heel, it has to be at the ball of the foot.
Some systems are better made than others, but any system that attemtps to compute the angle between 2 impact points to align your foot like IK should will automatically just fail here.
A workaround is to just use the regular skeleton setup, and just not pain the ball of the foot weight paint or the foot weight paint at all.
That way the character’s foot is always just under the calf and nowhere else…
Thank you for the suggestions, after more trial and error and investigating further, I noticed the plugin’s skeleton is lifted from the ground and suspect this is the root cause, hence I created a new Feet IK CR based on the asset skeleton (with the exact same settings as before) to replace the plugin’s Feet IK CR and it is working fine.
