Moho Forum

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.

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

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?

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.

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

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

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.

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.

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

try this:

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.

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.

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