MHX Hip Bone doesn't work as expected with Genesis 9

[John Blobago]

After converting rig to MHX, rotating the hip bone in X or Z causes the G9 figure's feet to be pulled off the ground plane.

Thanks again!

[Alessandro Padovani]

This is a generic issue with ik rigs, not specific to G9 nor mhx. That’s how ik works unless you use ik stretch. The ik goal has limits, if the limb can’t reach it then it just “points” to it. Personally I always use ik stretch both with mhx and rigify and my little custom rigs.

If there’s nothing to add please close as invalid.

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[John Blobago]

I'm fairly new to the animation/rigging side of 3D, so I appreciate the info.

The only part that confuses me is I'm able to perform the same rotation with the Rigify rig (the corresponding bone seems to be Torso rather than Hip?) with the IK Stretch parameter turned to 0 on both legs and G9's feet stay firmly planted. Is there some hidden parameter I'm not seeing?

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[Thomas Larsson]

Rigify is a very advanced rig which does lots of magic behind the scenes, whereas MHX is much more simple-minded and only adds a thin layer of control bones to the original DAZ rig. You can see that the DAZ rig behaves in the same way if you rotate the hip bone and then counter-rotate the thighs.

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[Alessandro Padovani]

Rigify may not show the ik goal issue for that specific movement, perhaps because the hip rotation is corrected around the thigh, but in general the issue is there if you don’t use ik stretch.

[John Blobago]

Ah, okay, I understand. Thank you both for taking the time to explain.