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plasticfrogCG
11-07-2010, 08:21 PM
Hello!

I was working with a character when I noticed the eyes started rolling real crazy. I figured out what the problem was but...I haven't a clue how to make an inverted connection. (i.e. object A rot.z = object B -rot.z)

Short and sweet I need the offset Z value of a constraint to be opposite of the rotate Z value of the eye joint.

I know how the expression editor works, I just don't know how to write the expression. :hmm:

Edit: D'OH! Sorry, I forgot to mention I'm using Maya 2011. I'm also using the abAutoRig script from Supercrumbly.

plasticfrogCG
11-08-2010, 11:22 PM
Would an image help??? It's really simple: offset Z should always equal the opposite value of eye_jnt.rotateZ

I just don't know how to write the expression. I don't know what the command is to get one attribute to equal the opposite of another. Please help!


http://fc02.deviantart.net/fs71/f/2010/312/5/0/50f994d58b091aee907e4d48fec4ff51-d32gat2.jpg

Dichotomy
11-08-2010, 11:47 PM
wouldn't "offsetZ = eye_int.rotateZ * -1;" work for this?

plasticfrogCG
11-09-2010, 01:51 AM
Yes! That's what I was looking for! I don't usually do a lot of expressions myself so I completely forgot what some of the basic functions were. *facepalm*

Thanks for posting, but I did manage to fix it on my own. I was going about the problem from a totally wrong angle. All I had to do was connect the HEAD rotate Z to the eye aim constraint offset Z and viola! Fixed! I feel dumb now, hehe.

Thanks for listening though! I always get good help here when I do actually find something that stumps me.

andyLP
11-09-2010, 04:52 AM
Hey you shouldn't have to anything to the offsets on a constraint..
Normally with an aim constraint you'd specify an 'up vector object' (see the aim constraint option box)
the up vector object is usually the head control itself., or a locator that follows the head.

That should stabilize your aim constraint.
So if your current solution breaks.. there's a new one!

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11-09-2010, 04:52 AM
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