FK Bones stretching

# 1 18-03-2006 , 06:40 PM

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Join Date: Mar 2005

Location: Illinois, USA

Posts: 250

Hello folks, I must admit that I really don't know what I'm doing with rigging in Maya and i keep getting stretchy bones when I try to do my IK/FK switch and that results in the bones stretching to create a linear interpolation instead of an arc... here's a quick sketch to show what I mean.

the problem is probably that I am using a parent constraint in order to get the position as well as the orientation of the secondary FK and IK setups.

Does anyone know how to fix this and still allow me to pass on the position to the full IK/FK switch setup or is scripting necessary?

Edit: oh yeah, as a temporary fix, I'm only parent constraining the root bone and leaving the rest with only orient constraints on them, but that may leave me with problem later. So I'm curious about an answer still

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Last edited by Funky Bunnies; 18-03-2006 at 06:49 PM.

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# 2 25-03-2006 , 02:35 PM

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Join Date: Oct 2004

Posts: 27

none of them should be parent constrained, try this:

1) create an arm with clavical, shoulder, elbow and wrist

2) select the shoulder and duplicate it twice (this will duplicate all the children too

3) select one of the duplicates and go modify > prefix hierachy names, and enter FK_, then select the other and enter IK)

4) Select your FK shoulder then yur original arm shoulder, orient constain, then FK_elbow, orig elbow orient constrain etc do the same with the IK.

If u want me to go into create all the blending I can, but that should be the weighting sorted.

https://www.andy-cadey.co.uk

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# 3 25-03-2006 , 05:24 PM

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Location: Illinois, USA

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right, that will take care of the orientation but the root bone needs to be altered in translation and rotation, so either there need to be parent constraints on only those root bones or I could have bones rooting from the pivot point that wouldn't influence any geometry just so that there would be arced motion and stuff...
it's hard for me to explain... are there any other ways besides these?

anyway, user added image

thanks for the response, man

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# 4 25-03-2006 , 05:28 PM

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its ok, basically because we duplicated the shoulder joint, that means that the all share the same parent, the clavical, so if u move the clavical, they will all move together user added image

, think of it a bit like fingers on a wrist, only they are all in the same place.

AnDy

https://www.andy-cadey.co.uk

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# 5 25-03-2006 , 05:33 PM

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Join Date: Mar 2005

Location: Illinois, USA

Posts: 250

ahh right, I'll try to give that a go, it's a bit more realistic than the parent constraint method.
Thanks, for some reason since I'm doing a mech leg I ignored everything I do for organics and forgot I could just use a 'clavicle' type bone. Thanks again user added image

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FK Bones stretching

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