Smart Bone Action - Weird Point Motion

[DrNibbert]

Hello everyone!

Sometimes when setting up smart bone actions i experience some really weird point-movement and i want to know what is the best strategy to avoid this/get rid of this.

I recorded a video of the problem:
https://www.dropbox.com/s/tdm2lyslhf50e ... m.mp4?dl=0

Each Key-Position for itself is fine, but the interpolation between is really messed up for some points.
I tried to fix it manually (in kind of a frame-by-frame-approach) or tweak the motion graph for those points to smooth out the motion, but it still produces really weird and jumpy results.

Can anyone give me a clue why this happens and what the best way to get rid of this is?

Thanks a lot!

[synthsin75]

Looks like more than one smart bone action interacting/conflicting.

[DrNibbert]

Hello, thanks for your reply, there is only this one action in the whole project right now Even if i delete everything except the bone layer and the one vector layer it still occurs

[synthsin75]

Hello, thanks for your reply, there is only this one action in the whole project right now Even if i delete everything except the bone layer and the one vector layer it still occurs

Then it sounds like bone strength is interfering with the smart bone point motion. If that's not it, you might post a link to the file so we can diagnose it better.

[DrNibbert]

Thanks a lot for looking into it!
Here is the file with the problem (i deleted everything thats not necessary)
https://www.dropbox.com/s/e4vkc30xtnrx5 ... .moho?dl=0

When you say interfering with bone strength - are Smart Bone Actions generally not intended to work with Flexibinding/Bone Strength? Or do you mean that there is some bonestrength of another bone that is causing the problem?

I turned of the bonestrength of all other bones and this strange behavior still occurs

[synthsin75]

When you say interfering with bone strength - are Smart Bone Actions generally not intended to work with Flexibinding/Bone Strength? Or do you mean that there is some bonestrength of another bone that is causing the problem?

I turned of the bonestrength of all other bones and this strange behavior still occurs

It's not that smart bones are not intended to work with flexibinding; it's that using them together can add an undue level of complexity.

If you go into your B21 2 action and delete the bone's keyframes, you'll see that the points are actually moving in a straight line from one key to the next. But with the bones moving, B21 is pushing the points toward the influence of other bones. So your final action pose looks good, but it's having to account for the altered bone influences the points are in, and that influence is changing as the smart bone rotates.

So you'd need to keyframe many more frames (often every frame) to keep correcting for the changing bone influence on the points.

For something like that, I'd be apt to go with pin bones instead of smart bones: http://www.filedropper.com/oorigside11example-3

[DrNibbert]

Thanks that really works a lot better than my approach!
Thats a great idea! I'll play around with the Pin-Bones-Method! Thanks a lot!