View Full Version : hand job

07 July 2002, 12:48 PM
Can anybody suggest a good arm-wrist bone setup where the hand inherits the forearm rotations (so that is aligned to the forearm by default) and then can be rotated independently of the forearm.

In my setup, I've got the hand bone orient constrained to the wrist null, which drives the animation of the arm IK chain.
The problem is when I move the wrist null around, the hand gets rotated at very akward angles, and takes a lot of retouches to get it to look right.

thanks in advance


07 July 2002, 02:29 AM
It sound like you don't have it orient constrained in world space so that the rotates of arm are being added on top of the rotates of your palm bone. So how you do this properly will depend on your package.


07 July 2002, 01:17 PM
I'm working in max, the null that drives the position and rotation of the hand is floating freely outside the hierarchy. Since the hand is orient constrained to this null, when i move it around it results in the hand looking akwardly bent.
What I'm looking for is a way of getting the hand to inherit the rotation of the forearm so that it will look nice aligned, and then be able to overlay the pose the hand by rotating the null.
any suggestions?


07 July 2002, 05:02 PM
I assume you have your joints all oriented so that the LRA's have X running down the joint...with that in mind here is a possible solution:

1] draw your arm joints like you normally would
2] split your forearm into 2 bones if you have not drawn it like that already
3] at the wrist/hand joint place a controlling object [ie: cube]
4] use the connection editor and create a connection between the Y and Z rotation of the cube and hand [so the cube's rotation feeds the hand's rotation]
5] create a connection between the cube and the joint closest to the hand on the forearm so the X rotation of the cube drives the rotation of the forearm

This method will have the hand inherit the rotation from the forearm joint...

the above methosd is what I khave done in Maya, but you are using MAX [ugh :rolleyes:]

Regardless, I hope this helps...

07 July 2002, 04:40 PM
Yo, thanks!

Tried your approach and works, albeit partially.
I used wire parameters (Max's version of driver/driven) instead of an orient constraint, that allows for the hand bone to inherit the forearm rotation and then be rotated at will.

At First I could get it to work only in the X axis. I changed the order of rotation from XYZ to local euler (ZYX) and now X and Z rotations behave as you'd expect.

The Y rotation (bones' axis in my setup) still behaves oddly, but I've still got some ideas to try to fix it.

Cheers and thanks again.


07 July 2002, 11:02 AM
LRA's ???

07 July 2002, 04:14 PM
Originally posted by TheDevil[DK]
LRA's ???

Local Rotation Axis.

07 July 2002, 04:51 PM
Doohhh... Thanks alot

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