CGTalk Orient Constraining Using Multiple Parents
 09-12-2013, 10:44 AM #1 coopascoopa25 New Member portfolio Courtenay Sydney, Australia   Join Date: Jun 2011 Posts: 10 Orient Constraining Using Multiple Parents Hey Guys, I'm in the middle of rigging a bird wing and I've stumbled across a small problem, so I was wondering if anyone could help me out. Basically my setup uses joint chains for each feather, that are orient constrained to two controllers, and then depending on how far away each chain is from the two controllers, its weight is adjusted. e.g. chain01 is constrained with a weight of 0.9 to control01 and 0.1 to control02 However. Each joint chain is in a different orientation to begin with, as all the feathers don't face the same way. So when I go to edit the weight that each control influences the joint chain, the joint chain shifts and becomes more bias to one control or the other. First of all, I'm curious as to why this occurs when maintain offset is selected when I create the constraint. Isn't the point of maintaining the offset that the joint keeps its original rotations? All the objects have the same rotation axis and are all zeroed out in the rotations. Am I wrong in how I think orient constraints work? Is this popping behaviour expected? And if so, does anyone know a way around it? I can't think of another way around the issue. Thanks! share quote
 09-12-2013, 11:08 PM #2 oddforce Beginner 🐟 Austria   Join Date: Jun 2005 Posts: 235 It would be nice if they kept still even during adjusting weights. My guess is that the algorithms behind the constraints are rather simple so that feature only works only for 0.5 & 0.5 weights. As a workaround you could give multiple constraints a try, I mean instead of multiple parents, and adjust their weights. Btw, with multiple parents there's flipping issues too when one of the parent orientation angles go over 180 degs. Even though the doc says it's using quaternion interpolation (weird) share quote
09-12-2013, 11:31 PM   #3
coopascoopa25
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 Originally Posted by oddforce It would be nice if they kept still even during adjusting weights. My guess is that the algorithms behind the constraints are rather simple so that feature only works only for 0.5 & 0.5 weights. As a workaround you could give multiple constraints a try, I mean instead of multiple parents, and adjust their weights. Btw, with multiple parents there's flipping issues too when one of the parent orientation angles go over 180 degs. Even though the doc says it's using quaternion interpolation (weird)

Thanks for the reply Oddforce Do you think you could explain to me a little bit more about using multiple constraints rather than multiple parents? I don't fully understand what it is you mean. As for the flipping issue, I've found if you set the interpType on the constraint to "shortest" the problem fixes itself.

 09-13-2013, 01:28 AM #4 Lomax Lord of the posts   portfolio Jared Lindquist Technical Animator Limited Slip Studio Orlando, United%2BStates   Join Date: Jun 2002 Posts: 707 Something else you could try - rather than constraining the joints directly to the controls, constrain them to dummy transforms. These transforms would be parented to the controls, but would match the joints' orientation. __________________ share quote
09-13-2013, 02:35 AM   #5
coopascoopa25
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 Originally Posted by Lomax Something else you could try - rather than constraining the joints directly to the controls, constrain them to dummy transforms. These transforms would be parented to the controls, but would match the joints' orientation.

Hmm that's something worth trying, and it keeps the organisation nice and clean. I've tried using dummy groups before, but they were parented rather than constrained and were not successful. I'll give it a go and see if I can get better results that way, thanks Lomax!

 09-13-2013, 02:35 AM #6 CGTalk Moderation Expert   Join Date: Sep 2003 Posts: 1,066,478 Thread automatically closed This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum. __________________ CGTalk Policy/Legalities Note that as CGTalk Members, you agree to the terms and conditions of using this website. share quote