Controll The Flipping Of The Orient-constraint

[thomas1234]

my problem is, that constraints only go to 180 degrees. and then flip...

My question is now, how can I controll it? how can I say, this constraint has to flip at - for example - an rotateX-value of 90? or 180?

I`m having this problem at the upperarm and lowerarm-twisting. these inbetweenjoints flip, and flip, and flip...

Can anyone tell me a solution? I tried to break connection of the rotateX-parameter (the twisting-achse) and make an expression to the rotateX... didnt work. maybe I didnt find the right expression.

please help me!!!

thanx
Thomas

[drblacksnake]

are You sure its orientConstraint? not poleVectorConstraint?

[thomas1234]

yes, Im sure.
Im not talking about flipping-elbow-problem.

my problem is the flipping of the inbetween-twisting-joints in the upperarm or lowerarm.

[joojaa]

QUOTE(thomas1234 @ 02/01/06, 11:51 AM) [snapback]226923[/snapback]
my problem is the flipping of the inbetween-twisting-joints in the upperarm or lowerarm.

And why exactly woudl anyone in their sane mind use a orient constraint here? And yes thers realy no good way of doing this.

[thomas1234]

because I have two chains (actually 3)

FK-upperarm
IK-upperarm
middle-upperarm

the middle has an orientconstraint between FK-upperarm and IK-upperarm.

2 problems:
1. the IK-upperarm-twistvalue (rotateX) flips at 180 degrees
2. I have an orient-constraint from FK-upperarm and IK-upperarm to middle-upperarm

@drBlacksnake:
maybe you were talking about the right problem.
But I dont have problem with the whole elbow-flipping.
My problem are the inbetweenjoints of upperarm and lowerarm (because values flip at 180 degrees)

[joojaa]

QUOTE(thomas1234 @ 02/01/06, 02:12 PM) [snapback]226940[/snapback]
because I have two chains (actually 3)

No matter you still dont need a orient constraint anywhere on the chain! Even if you need semless toggling between the ik and fk still dont need the orient consraint. Only reason for this is se if you need a ulna bone rig wich is very rarely needed.

Yes i know most novices try to FORCE a constrain in here into the equation because they think it solves something special. But it realy does not give any benefit plus ist absolutely hideously horrible to work with.

Anyway to aswer your question yes it spossible to controll the orinent conststraints working area by adding a plusimus average node and ofsetting the result value with this. And then offsetting teh read ofset of the orient constraint.

BUt you better get rid of the constrait alltogethere as you dont REALY need it for anything.

[drblacksnake]

i see. essential is to have both target and constrained joints similar in their axial orientation and rotation order aswell. as far as i've done rigs like this, they always were working fine.

[thomas1234]

Great, it works now :-))

my problem was just, I didnt do the chains very precise. And - when I made some experiments with the joint-values, it "crashed", and didnt work anymore...

But I solved it a bit different then. I did it with jointOrientX. just changed it to 90 degrees or 270 ... and then the flipping was at another point.

@Joojaa
you said, I dont need an orient constraint for toggeling between FK and IK-chain?
would interest me, because there are also some other small stupid problems (sometimes the blending from IK to FK is very weird)

[ytolyccuz]

QUOTE
you said, I dont need an orient constraint for toggeling between FK and IK-chain?
would interest me, because there are also some other small stupid problems (sometimes the blending from IK to FK is very weird)

Although you specifically addressed this to Joojaa, since the post has been unanswered for more than a month, I would just like to share some stuff...

We can toggle from FK to IK by:

1. enbaling IK FK Control on the ikHandle node\IK Solver Attribute section.

2. To switch from IK to FK. Ik blend=1. Position a pose using IK.
   2.1 set a key on the IK handle AND all the joints that will be manipulated through FK (without manually altering the transformations). --> This ensures that the IK is used and at the same time specifies a starting point for the FK-driven motion.
   2.2 on a later keyframe, set a key on the IK handle with Ik Blend=0 to enable full influence of FK. Manually manipulate the joints previously keyed to the desired pose, and set the keys for all the manipulated joints.

3.0 We can expect a smooth interpolation as the IK recedes and the FK grows in influence.

4.0 As for FK to IK it's just basically the same: key the ikHandle with Full Influence of FK using Ik Blend=0, key all manually assigned rotations. On a later keyframe, set Ik Blend=1, pose using ikHandle, key ikHandle. That's it we're back to IK.

There we have it IK - FK toggle with no Orient Constraint.

Pardon me if my post was too "step-by-step". You probably already know about this... but just in case this can help you or others, my time was well spent.

[dunkelzahn]

Well, it gave me some input, so thank you very much!

Chris