View Full Version : Arm set up.

02 February 2004, 02:02 AM
Hi all.

I'm trying to rig up an arm using a 3d buzz tut.

The problem I'm having is that at one stage your supposed to move the IK handle from the forearm joint to the wrist joint by selecting the end effector, pressing insert and then snapping it to the wrist joint.

The IK handle is then supposed to be at the wirst. The problem I'm having is that although the end effector moves to the wrist the IK handle stays where it is.

What am I doing wrong?

Thanks alot for replys.

02 February 2004, 02:55 AM
unless I'm mistaken.... that was an old trick...

the IK in maya 5 is different and "fixes" that from working ;)


02 February 2004, 10:22 AM
Thanks, well I'm using Maya 5 and I think in the tut they were using a previous version.

Matt Leishman
02 February 2004, 05:07 PM
I seem to have figured out a work around that hasn't failed me yet, but if anyone finds any flaws, please let me know . . .

here's what I do:

I have my 4 joint arm chain (shoulder, elbow, forearm, wrist). I create my RP_ikHandle from shoulder to forearm. Then I select the ik handle and change its default Ik Blend attribute from 1 to 0 (in the channel box). Then I go into the ik handle's attribute editor and change its stickiness attribute to off. Then I select the end effector and hit insert and point snap it to the wrist joint (then hit insert to complete that action). Then I select the ik handle itself and point snap it to the same wrist joint. Then I turn the stickiness attribute back on, and then I change the Ik_Blend attribute back to 1.

Now you should be able to grab the ik handle (now at the wrist), and translate it til your heart's content, and still be able to have the freedom to rotate that forearm joint to simulate your forearm twisting.

hope that helps some!!

02 February 2004, 09:46 AM
Thats great thanks.:thumbsup:

Matt Leishman
02 February 2004, 03:58 PM
my pleasure, hope it worked for ya!

02 February 2004, 10:38 PM
You can also group the ik handle to itself then move the group pivot point to the wrist.


02 February 2004, 09:40 AM
Or use a influence object to simulate a forearm joint. I've done this a couple times. Just rig up the influece object to rotate at a fraction of the wrist joint and paint the forearm to the influence object.

John Homer- I saw you work at Weta. Do you know Eric Tang? He's a character TD at Weta. I'm currently working with his brother, I was just wondering if you guys at Weta get to know each other much.

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