Ik Spline problem with tongue

[zbgump]

I have my tongue set up with a joint chain and an ik spline handle. I created my own curve for this ik, then created clusters out of the vertices. These clusters are parented to appropriate joints in the head regions, so the tongue will deform when the head turns.

When I turn the head, the Ik handle is not moving with the head, its staying in place and this seems to be causeing the tongue to roate when I turn the head. Maybe its the end effector thats staying in place; I don't know.
It almost seems like the Ik is "sticky" although sticky is definately turned off.

Thanks for any input.

[aaron_johnson]

mmmk. for this i would just parent the control curve to the root jaw joint, so that the tongue moves and stays inside the jaw when the head turns and tilts etc. and then animate the control curve's CVs directly to get extra deformation effects (like a poking out tongue

is there some reason u need clusters...?

[zbgump]

I thought I needed clusters because they had transform nodes, so I could animate later. I basically am working with what I learned in the Gnomon skinning 3 tape. The instructor had a long toung that needed to protrude from the mouth. He had the clusters towards the base of the tongue parented to the neck joint, and the ones closer to the tip parented to the jaw joint; this way the tongue would deform when opening the mouth but not stick out the back. Here's a screenshot of my problem. http://users.rcn.com/rmkerr/ikspline.jpghttp://users.rcn.com/rmkerr/ikspline.jpg

As you can see the the tounge, curve, and clusters are moving with the head as it turns. The Ik handle is staying in place and this is causeing the solver to twist the tongue (at least thats what I think is happening). In the tape, when he translates the clusters, the tongue deforms but the ik handle seems to stay with the tip joint. I believe that followed the instructions to a "T", but I know he's using maya 4/4.5 in the tape. I'm using 5, I don't know if that makes any difference.

I'm pretty new to all this, so I guess anything is possible

Thanks for your reply

[aaron_johnson]

mmmk. i know some ppl with 5.0 have had issues with IK handles when a particular FK-IK Switching setting is enabled... i can't recall exactly which setting cause i'm only on 4.5. however i wouldn't have thought it would be a problem anyway because its a splineIK u r using... hmmm maybe something to check anyway.

if that's not it, try making a new scene with a few bones and a spline IK handle (without clusters) to see if the handle sticks to the end. u r rught that the handle stays with the tip of the control curve in 4.5.
if it works with the basic setup then its something to do with the clusters or way they are parented in your head scene. if the handle still doesn't stick then its a tool setting with IK, try resetting to deault.

lemmi know how it goes

[zbgump]

I think the problem you are referring to is discussed at cgtalk in this thread. I tried turning off Ik Fk control and it seemed to make no difference. I tried this with a simple rig in another scene, no clusters, and had the same results. I sent an email to Gnomon; Alex Alvarez got back to me pretty quickly when I had a question about the Organic Modeling tape. Maybe someone else has already encountered this problem

I guess I'll just use a short tongue without a spline handle. I was really only using it to follow the tutorial. Maybe its a bug, who knows. I'm running Maya on OSX, and I definately found one bug in this version: You can't turn off "show all columns" in the component editor. This bug also seems to exist in Maya 4.5 on OSX.

Thanks for all your input! I guess its time to move on to something else!

[zbgump]

I found the answer in the forums at Alias's site. I had to disable the IK/FK control up in the skeleton menu. LOL! I really wish I had a dime for every time I thought I found a bug in Maya!

Thanks for the help!

[zbgump]

I Spoke to soon. Although disabling the fk/ik solved the problem of the handle not sticking to the end joint, it seemed to have no effect on the spline twisting.

I tried making a cluster for each individual vertex, and then I parented all of the clusters to one joint, the jaw. Rotating that joint still causes the tounge to twist in Z while I rotate the joint in Y or Z. Whats even stranger, is if I rotate my neck joints while the clusters were only parented to the jaw, the twisting still occurs. I would think that roating the neck joint is simply translating the jaw joint, so the clusters are then only being translated. The spline and the tongue are only being translated so this twisting is an absolute mystery to me.

[ollieflip]

I've had the same problem with the same dvd's tutorials by Alex Alverez.

After you rig your tongue according to AA. then I fixed it by perenting the tongue's root joint to my head joint, but you might want to perent yours to some thing else depending on your rig setup,
but that's it, it will looks like another branch coming of the main seleton but it will act the way an IK spline handel should (twist, roll, offset) and no undesirable rotations.

Most important thing is to make sure "Root On Curve" is ON, if not it won't work properly.

[zbgump]

I emailed Alex of Gnomon and he responded:

Hello,

Yes, this seems to be a bug in 5.0.
I just tested it and got the same results.

I have a meeting tomorrow with the Senior Applications Engineer from Alias
and I'll bring this up... and have him log a bug report.

Email me again in a couple days and I should have some sort of answer.

[ollieflip]

I reneg my last post
it broke as soon as i tryed connecting the twist and offset to my jaw.

sorry for my waist of space earlier.