I got the left and right hand to follow the gun with child of constraints, but the right hand jitters between frames and when moving either of the hands the position changes to a different one between frames.
A guy on reddit told me it could be my computer, but upgrading it isn’t really an option, so maybe someone can tell me another way to fix it?
Computer Specs:
i5-9500
GTX 960
16 GB 2666mhz ram
I can’t tell from the video exactly, but I sometimes get results like that when there’s a loop in parents, say the gun is parented to the hand bone, while the hand bone has a child of constraint on it to the gun, so that might be something to check out.
Welcome to the BA Forums.
If is is not a loop in parenting / constraints…
Have you checked interpolation?
I am guessing it has been set to constant - and that is causing the stepping.
Thank you!
I double checked, its set to bezier and there’s no green lines in the action editor
Hi, the right hand is parented to the gun stock while gun itself is parented to the left hand, after that, the gun and the left hand get parented to the right hand.
Is this considered a loop? the constraints are all 1’s and 0’s with no values inbetween
If I’m interpreting correctly, that does sound like a loop. The right hand is try to move with its parent the gun, but the gun is moving according to its parent, the left hand, which is moving according to its parent the right hand, which is moving according to gun, which is moving… ECT, and because the software doesn’t know how to interpret that you’re getting that weirdness.
At least as far as I can tell without actually seeing the file.
If you want both hands to move with gun (which is how I understand this, correct me if I’m wrong) is there a rigging consideration that prevents both hands from just getting a child of constraint to the gun?
Here’s the blender file if you want to take a look at it.
What do you mean by “rigging consideration”?
I mean, is there something in your rig that prevents both hands being constrained to the gun.
Sure looks like a cyclic dependency from the video, didn’t look at the file.
Cyclic dependencies are reported in the console window, consult that for error messages.
Randy
After looking at the file and messing around with it a bit it is a loop. Adjusting the child of constraints to remove that loop should fix the problem, no need to upgrade your PC. 
I’m not sure what exactly you’re looking for, but I got decent results both by constraining the left hand to the gun, then the gun to the right hand and by constraining both hands to the gun (Not at the same time, for clarity. Those are two different set ups).
Normally i control everything using the right hand, which controls the gun and the left hand, but when i switched the parents for this animation in specific, the right hand started to freak out as you saw in the video.
What do i need change about the constraints?
For this specific animation, I’d remove the constraint from the gun to the hand, so both hands follow the gun, since that’s what the hands seem to be doing in the animation. In my version of the file the animation plays as before after doing that, but without the jittering.
A more generalized solution (to enable the parent switching you seem to want) might take me a minute, if I can figure it out, but I can give it a shot if you want.
This is the correct mentality- hands should be children of objects, backwards though that may seem
Ok I’ll do that then, thanks a lot for your help!
No problem.
Should they ? I wonder why ?
A couple of ways this could be done:
This can’t be done as it would be done in real life, both hands controlling the gun, as the gun can’t be a child of both hands.
Any other ways this could be done that I am missing?
Randy
I like to use the example of a character with their hand on a steering wheel, turning it, then moving to a gear shifter and shifting it, then finally moving to the car door and pushing it open. If all these objects were children of the hand bone, you’d need to find a way to preserve transformations when they lost their parent- that is to say, the steering wheel A) shouldn’t move when the hand is no longer attached, and B) the wheel should animate the same way whether the hand is attached or not.
To turn the wheel if it was a child of the hand, you would sometimes animate the wheel and sometimes animate the hand, which gets messy fast. The other way around, it’s much simpler- to turn the wheel, you just animate the wheel. If the hand is attached, it’ll turn with it, otherwise it doesn’t.
It’s simpler, cleaner, and easier to animate