G3 MHX turn 180 foot IK bones, when Snap FK to IK (or IK to FK), so it cause issue with zero pose (easy solved)

[engetudouiti]

I suppose one reason is, I never merge toes when Convert to MHX, so I can not set Priority as high.

but I really like current Thomas way to manage daz G3 foot driver, then I have some customize version, too (both and pro and con)

Then usually this problem not so clear. because add ON pefectly trun around related chain, then we can not see problem without you reset pose.

I really hope if Thomas can solve this issue (I hope you forgive me option not to merge toes, so if you can take time check it please)

1. load G3 then without merge toes. but just convert to MHX rig.
2. with Armature viewport setting, not use shape but use Octahedral and show Axis. because so you can catch when bone turn around happen (but keep deform as if it worked correctly)
3. keep zero pose, then check current Bone axis of foot.IK R/L . , you should confirm both bone Z axis UP. remember it.

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4. use snap FK to IK (FK mode). you do not see any problem, then use snap IK to FK again, so now you return to IK mode. with out change anything.

5. you may not still see problem but this time actually some foot related bone turn 180 . then foot.IK R/L now Z axis Down.

6. I usually did not notice this issue, then try to work going on.. I feel sometimes, my foot widgt shape reverse.. but I usually miss it, but you may sometimes check default pose. so select foot then clear pose . now it usually show this twist ugry foot.

7 once it happend after that the change flip not happen. I can reduce by turn around bone again, but I feel I can never return defautl rotaiton for the scene. (flip around many IK chain, then once it show correctly, but after all it easy cause issue for most of IK chain of foot)

I seems there should be way to solve issue, with constrain setting.. but still can not find what cause it actually…I first though if it caused my custom version only, but not.. as default when use IK snap to FK function, the constrain somehow turn 180. those IK foot chain bones I think. hope if you can easy solve issue, (I do not remember when it actually happend but I sometimes see this issue so it may not related recent tiwst up date.. I suppose.. it remain long time for non merge toes option .

[engetudouiti]

It was actually simple mistake,, (or you happend to make foot IK chain so)

the Foot IK>toe rev IK>foot rev IK are chain bones. but you happend to twist only about Foot IK as 180 for rest pose.

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or I suppose you need to twist 180 (roll) for toe rev IK and foot rev IK only ,so these 3 bones roll can align with use same axis angle when they along with one line chain.. (foot Ik bone face to blender foward direction, but other 2 bone face to blender buck direction. actually you need to reverse (add roll 180) for foot IK bone.

. after I change so, it never happen. I test with Left foot only. so about Left there is no problem. then confirm it shoud work.

I still not perfectly

To easy correct it, when generate mhx rig, only add 180 roll for those 2 IK foot bone only. (for G3 non merge option) then it work.

I do not test with other irg still, (i need to finish my customize). but if you have such chain for other rig to make reverse foot, I suppose you have same issue for those rig too.. when you IK bone fit to FK bone. (some bone Y axis may look reverse (front and buck etc), about those case you need to add roll 180 to Align bone axis for chain to consrain swicher work. (I do not know which constrain switcher actually relate this issue though)

[engetudouiti]

Thomas

Actually merge toe or not is not matter. this problem should happen with MHX (though I do not check G8 now but I suppose without you change roll for MHX IK foot, it should show same thing.

when I snap IK to FK actually you twist 180 along local Y, for IK foot , but it show same deform. (maybe deform bone happend to keep same rotation) but when you set zero rotation for IK foot, it break. Once you add roll 180 for IK foot r and l as rest pose, you never see this problem. It must need to correct for MHX. (I had believed, everytime when I see this problem my customize way was wrong or I miss pose something, but not.. it seems long-time issue we just miss it.)