FKIK Setup : Flipping Orient Constrain problems

[loked]

I could be way off here, but when you created the three skeleton's for this FK/IK arm. Were all the joints that are being orient constrained duplicates of one source? Basically what I'm getting at, is did they all have the same rotation order, local rotatin axis and joint orientation? Just check to make sure of these thing, it might be whats causing it.

later:wavey:
loked

[ajsfuxor]

all were duplicates, and hence had identical everything (plus i also double checked this, so nothing there)

:(

[olivier georges]

hi,
if you use maya 4.5, don't try to make an ik/fk rig with orient constraint, these constraint are evaluated in euler angle, and you will have some flipping , in maya 5.0, there is a new algo where you can choose the blending method, choose shortest and you will never have flipping prob...

olivier

[ajsfuxor]

I still get the flipping problem with the shortest on, but it is miniable and bearable.

If there is nothign around this problem, what what other methods are there for creating IKFK arms other than orient constraints?

[brunodek]

hello,
sorry for my poor english.
try the IK spline with a linear spline (create on the joints),
and easy in twist.
you created a cluster by point of the curve, and you move the clusters.

nono

[kiaran]

I have encountered the exact same problem you are describing and I also decided that it can probably only be fixed with the 'cache' setting under the orient contraint interpolation type.

I have just started using Maya 5 so I don't know yet whether oliveir georges is correct but I suspect that Alias has probably fixed this.

That being said, I haven't used the 'cache' interpTyp on an orient contraint, so I don't even know how if this would work. As you said, the flipping can be managable but is still very annoying.

I would like it very much if someone out there could shed more light on this issue.

Thanks,
Kiaran

[dwalden74]

Hi guys-

Since v5, I´ve been using orient constraints with interpType set to "shortest", and have not encountered any flipping whatsoever. You can test this setup by using mydwRiggingTools (http://www.david-walden.com) rigging scripts in the MEL section of my site. Neither I nor anyone else that has used this tool has reported this flipping problems (however if you do find something awry please let me know!).

I still get the flipping problem with the shortest on, but it is miniable and bearable.

ajsfuxor and kiaran, could you guys post a simple example file where this occurs so I could look at it? If there is indeed a problem I would sure like to know about it.

I haven't used the 'cache' interpTyp on an orient contraint, so I don't even know how if this would work

Last time I checked, this was pretty well documented in the online docs.

If there is nothing around this problem, what what other methods are there for creating IKFK arms other than orient constraints?

You can also do this via a blendColors node, feeding the XYZ joint rotations into the RGB values respectively. I haven´t used this on an actual rig, but I´ve tested it and seemed to work rather well.

That being said, I´d recommend limiting the amount of frames in which the blending action occurs in your animations. Usually you should manage it such that the blending happens over the course of just one frame (and if there is still flipping, which there shouldn´t be, the worst case is you´ll have some minor motion blur artifacts in the render - I´ve seen this even in the highest quality feature animation).

:beer:
David

[kiaran]

I have just imported some of my old rigs into my new Maya 5. The flipping problems still arose but by simply setting the orient contraint interTyp to 'no flip' the flipping has vanished and I can't replicate the problem anymore. Yay!

:bounce:

[Gnimmel]

I too have had a lot of problems in v5 with the new orient constraint, but I never ran into these in earlier versions (I must have been lucky)

There is a attribute in version 5 called useOldOffsetCalculation (uooc) which turns the calculation back to the old v4.5 and below way. This is good for old rigs and has fixed all the problems I've had with them, but not always a solution for maya 5 rigs. Eitherway, here is one more flag you can try to fix your problem.

To set this flag either find it in the extra Attributes tab of the attribute editor, or use MEL,

setAttr pCube1_orientConstraint1.uooc 1

Richard

[dwalden74]

Richard-

Could you please post a simple example scene where this problem occurs? I assume you are also referring to the flipping problem (which I cannot replicate but would like to take a look at).

thanks-
David

[Gnimmel]

Originally posted by dwalden74
Richard-

Could you please post a simple example scene where this problem occurs? I assume you are also referring to the flipping problem (which I cannot replicate but would like to take a look at).

thanks-
David

David, I'll see if I can find anything. Most of the characters I've had this problem on can't be posted for copyright/non disclosure reasons. I might be able to take one apart and post just parts of the skeleton without breaking any contracts.

Richard

[dwalden74]

Yeah, I don´t want you to post a character, just a simple joint setup where you can replicate this problem.

thanks-
David

[Gnimmel]

Hey David, just a quick post to say I havn't blown you off, I got the dam flu and havn't been feeling like opening up Maya for a while.

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