View Full Version : Locator and wrist rotation problem

01 January 2005, 08:54 PM
Hello all,

I am doin an internship here and was sent a problem to try and figure out. I was given a model skinned and all, the problem is that a locator is parented to the wrist joint of the skeleton and is charge of 2 of the rotations on that joint and used (by way of connection editor) to rotate the forearm joint as well. The issue i am havin on the forearm rotate and one of the wrist rotations the actaul rotation of the joint is the opposite of the desired, i said rotate like 8 times in there.

If anyone could help me out it would be greatly appreciated. also if my expanation is not clear enough i could try again. Thanks a lot

01 January 2005, 11:34 PM
Easiest way to reverse the rotations is to stick a MultiplyDivide node in between your connection.

So instead of connecting (for example) locator.rx --> forearm.rx

create a multiplyDivide node: createNode multiplyDivide;
connect through the connection editor: locator.rx --> multiplyDivide1.input1X
set multiplyDivide1.input2X to -1
then connect multiplyDivide1.outputX --> forearm.rx

Matt Leishman
01 January 2005, 08:37 PM
yes, this math node solution as detailed here will work, but its a band-aid. I suspect that the locator does not have the same local rotational axis orientation that the wrist joint. If the axis orientation of the locator is initially matched to the wrist joint then once you connected the various rot channels via the connection editor you wouldn't have this problem to begin with.

just something to think about next time you approach this part of the setup.

01 January 2005, 11:03 PM
easy solution is to use an orientation constraint from the hand to the controller, Matt is right, the problem is that the locators orientation is XYZ (default for shapes) and obviously your joints local rotation axis is a different setting.

Next time give the orientation constraint a shot or try to look at what control objects you are going to be using the next time and plan your local rotation axis :) (little trick I use is implicitSphere's for the great).


Matt Leishman
01 January 2005, 11:25 PM
you're not following me around are you shawn? :D

Its a good thing you are tho, you've got more informative things to say than I do each time. Thanks for the help.

01 January 2005, 11:55 PM
haha...yes Matt...I am stalking you :twisted: after all, you were the lucky one who got the R&H job heh :P

haven't seen you on the boards much at creaturetd! Where you been?!


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