IK bone contraint - create fixed section?

Support Animation and Rigging
1

Hi folks,

Please check out the video linked below.

In the vid, i bend a chain of bones by moving the first (or last, not sure about that!!), and, because i’ve put an IK contraint on it, the rest bend accordingly.

But my question is: imagine that i want two bones in the middle of the chain to stay locked to each other in a certain orientation, like straight, or at a right angle, or whatever. Is there a way to do that, while still having the constraint work to the end of the chain?
So then i would have a chain looking like i manually arrange two bones to be in the video at 0:06 in the video. And if i change the curve some more, like bend it more, these two bones will still remain straight?

I guess another way of asking it is: is there a way to tell the constraint to skip specific bones in the chain, while still effecting the ones after it?

Thanks in advance!

2

In pose mode, you can set IK limits on the individual bones.

image
image776×320 28.7 KB

You can lock the rotation entirely, or set a range of rotation on the individual axes.

3

Thanks, that works to keep two bones straight.

But how do you fix the two bones to another angle that’s not straight?

4

You can set them up how you want them to be positioned in Edit Mode, then lock the axes in Pose Mode.

The rotation limits are based from the rest position of each bone.

If locking the axes doesn’t do what you need. Take a look at the Limits just underneath.

image

5

Another option would be to take them out of the equation completely, and parent them to a bone that is allowed to move with the chain:

image

Knowing more about the specific setup would lead to a better solution.