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# 1 28-05-2006 , 05:05 AM

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I am currently trying to get inverse kinematics working on the spider machine I am building here:

https://forum.simplymaya.com/showthre...threadid=21507

Now I have the skeleton in a basic pose, but when I apply the IK handles to the end points of the skeleton, the skeleton just jams in some weird position and won't do what I want it to do at all. I have limits on the rotations of the joints. I'll post a couple of pics of the skeleton before and after I apply the handle.

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# 2 28-05-2006 , 05:12 AM

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before

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# 3 28-05-2006 , 08:01 AM

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and after

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# 4 28-05-2006 , 12:05 PM

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What axis is facing down the joint and what rot limits have you put in?

Jay

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# 5 28-05-2006 , 12:43 PM

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try setting a prefered angle on the middle joint before applaying IK with default settings.
.

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# 6 28-05-2006 , 06:26 PM

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thanks for advice and questions. It seems like the IkSpringSolver is what I want from the description. does anyone have any experience using that, since I am not sure how to set it up properly.

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# 7 29-05-2006 , 02:26 AM

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ikspringsolver is nothing special.
its just like the rpsolver.

its set up just as any other ik solvers in maya.

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# 8 29-05-2006 , 01:39 PM

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ok, so spring doesn't work either, so I'm stumped. The down axis is the y axis. the far left joint rotates only about the y axis, and the rest rotate only about the z axis (in and out of the page) from right to left, joint 1 rotates from 0 to 45, joints 2 and 3 rotate from -45 to 0. I have a suspicion that part of my problem might lie in the fact that I have had to move the joints out of the planes in order to get them to centre on the object joints, since the centres do not all line up along the axis. I'll attach the skeleton so you can take a look.

Attached Files

problematic_skeleton.mb (63.1 KB, 239 views)

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# 9 29-05-2006 , 04:41 PM

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it works fine here.
the problem is simply because you had a lot of rotate axis locked on joint 1-5.
just unlock them and it works fine.

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# 10 29-05-2006 , 08:04 PM

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I tried unlocking stuff, but then here it just goes and rotates around axes that I don't want it too. Those joints are all pivots, and can only rotate about one axis.

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# 11 29-05-2006 , 08:10 PM

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you did however inspire me. removing all the axis locks, and then setting the rotate limit info on all the directions I don't want rotation in works perfectly. any idea why?

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