Problem with Stretch/Wrist Joint in Maya

#1

Hi guys !
I’m looking for some help with a very simple stuff. I still can’t find the solution to this problem. Hope someone can help me.

I have a simple cartoon character, and I’m getting some problems with the arms.
I’ve made the IKFK system, and IK stretchy arms. You’ll find that the mesh is the control object (I like to have a clean viewport).
Now, the problem is that when I rotate the COG or the chest, the wrist joint makes a small movement. I’ve tryed with an SC on the hand, but it’s still moving… If you check on the legs, it’s working fine, but this small problem its driving me crazy…

I’ll leave you the scene, and perhaps someone can figure it out.

http://www.mediafire.com/download.php?wwbv33bl3m1smet

Thamks to all !

#2

I can’t download your file right now but my first thought is where is the pole vector handle located?

#3

Its located on the Rp solver on the wrist joint…

#4

If you have a handle for the Ik and a handle for the pole vector they should not both be right on top of each by default. Most likely as soon as you move the pole vector you’d get a pop.

Although after rereading your post I’m confused as to what’s parented to what. If you rotate the chest I’d expect the hands to move … as the arms are attached to the torso?

It’ll be a few days before I can download your file… if you feel like posting pics of the problem maybe it’ll be more clear as to the problem.

#5

Without digging through your scene too far. It seems like something is off with the stretchy nodes. Check your distances being used and make sure they’re accurate, and make sure things that are supposed to be at the exact same spot in space, are actually in the exact same spot, Minor differences in transforms can be a world of hurt. i.e. IK cntrl, effector, and any sort of measuring nulls for stretchy not being centered on eachother.

#6

Thanks for the answer guys.

Well, I made the arm rig again, controlling every single null pivot, using the accurate measures for the distance nodes, and I still got the same problem. Cant figure it out.

It makes the same small pop without pole vector, so, its a different problem.

I’ll retry again tomorrow and post what I can achive.

Happy new year !

#7

Well, still can’t figure it out . . . if anyone else has another idea…

#8

I just look into your scene and I’ve noticed that it’s your IK on the hand which doesn’t evaluate correctly. (When you display all, you can figure the handle to be in place but it’s not constraining the hand.

I’m not familiar with maya in production yet (I’m only with better tools :-p), but I think using IK to constrain bones is bad idea.

So you should use a constrain from the controler to the wrist. But doing this, the others constrains on the FK don’t evaluate correctly, and your forearm IK too (seem to be your stretching nodes working instead folding the arm).

But for my own point of vue, I think, you should separate in a better way IK and FK limbs instead of constraining each other, making one (IK) master on the other (FK). So it may cause problems on animation and it’s more difficult to repair or add new features.
But I repeat, that’s my point of vue and I’m too new with Maya.

#9

Force the sticky mode on you Ik handles

#10

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