Lost Adventurer, Aleks Kirilenko (3D)
LC #42 Pipers Alley

View Full Version : Constraint Problems

04-24-2007, 08:46 PM
I'm trying to make a character move his arm (which has an IK handle on it), grab a door handle and close the door. I parented a locator to the door handle, then I parent constrained the character's hand to the locator. The problem is that when I key the weight on the constraint to zero (before the character grabs the handle in the timeline) the constraint is still effecting the arm IK. Is there something I'm doing wrong?

Joe Hughes
04-25-2007, 03:59 PM
did you get your order correct? select the locator, then select the handle and hit p so now the locator is under the handles heirarchy right, then you select that locator, shift select the ik ctrl and parent constrain making sure in your options that you have the translate and rotates both checked to all, your weight is set to 1.0 and maintain offset is checked.

04-25-2007, 04:18 PM
Yeah, I got the order correct, I've actually re-done it several times, thinking I hadn't done it right. Someone at Highend3d said that constraint weights don't work this way, that I needed a second constraining object, so that when the weight goes to zero on the first constraining object, that influence (weight) shifts to somewhere else (i.e. a second constraining object). I know in Maya's help tutorials that is the way constraint weights are explained (A character's hat is constrained by two objects- his head and his hand- and when he removes his hat the weight shifts from the head constraint to the hand constraint) Is this correct? Do I need two constraining objects, if I want to key the influence from my constraining object to zero?

Joe Hughes
04-25-2007, 11:49 PM
you may need to do something like that. ive come into a situation a few times where i had an object exchanging hands from one character to another. if they used some sort of visibility switch what i would do is duplicate the object, parent constrain it to both of the other objects and turn if off and on where they switched their visibility (on at say 32 to off at 33 and the other turns on) switching the constrained weights pretty much on those frames right. then once i have that duplicated object following the movement that the 2 objects together were doing, i would run a bake simulation on that object on the translate and rotate channels so the constaint now does nothing and there are only keys on it in world space. run a euler filter on the object to make sure theres no flipping and youre good to go.

hope this way of thinking applies to your issue.

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04-25-2007, 11:49 PM
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