New to IK Bones, How to Fix Wobble?

[catlover8976]

Hello,

I hope this is the right area to post a help request on this. I'm very new to figuring out IK bones, but seem to have grasped the basics on how to make them. However, when I do very slow motions with them, the whole bone structure connected to it will 'wobble' while following it. Is there a way to stop this? I've had a good look around but didn't see anything about it anywhere.

Here's two images of the leg rig I have set up. There's probably cleaner ways of doing this, but I've always tended to try and work with my limited knowledge to find ways of getting what I want.


Thank you for your time.

[synthsin75]

Adding a rotation keyframe to the problem bone/s will typically fix that.

[catlover8976]

I'm afraid I don't know what that is or how to use or apply them. Is there some info I could get on how to use that somehow?

[synthsin75]

Just go to the first frame that a bone in the IK chain starts to misbehave. With the transform bone tool, rotate the problem bone in the direction you want it to bend.

[catlover8976]

I've been doing that anyway and it has had no effect on the wobble.

[synthsin75]

Maybe you're talking about something different then. Can you post a video or file with the problem?

[catlover8976]

I discovered that if I 'only' rotate it, there's no wobble, but if I move the top bone as well as rotating I still get the wobble. I need to be able to move it to show the hip moving, so I'd like to find a way around this. The wobble shown here is most noticeable at the end, but it's also in the rest of the animation if you look closely enough.

[synthsin75]

I can see what you're talking about, but I can't replicate it with the same target bone and hip translation you seem to be doing. You're not using any noisy keyframes, are you?

Can post a file with only the effected bones? No artwork needed.

[catlover8976]

I'm using smooth keyframes for everything. I'm not sure if it might just be the front leg, but I've given you both legs so you can compare.
https://www.dropbox.com/s/uet8ym4nsk6rw ... .anme?dl=0

[Víctor Paredes]

try this:

[synthsin75]

On the front leg, you've animated the bone scale of both the thigh and shin bones. See if the wobble still occurs if you delete those scale keys.

[Greenlaw]

That was very informative, Victor. I was never quite sure before when to use the Arc IK option. Now I know.

Interestingly, when I was setting up the mocap rigs for the cats in our cgi Brudders music video, I ran into issues with the rear legs and the solution was similar to what you set up in your video--even though I'm using mocap to drive the rig, I'm hand keyframing the rotation of the thigh bone as needed.

[catlover8976]

Thank you Victor. Setting the top bone to an independant angle fixed it right up.