Breaking a bone chain

[pequod]

Hello,

Is it possible to disconnect a child bone from it's parent? e.g put the head bone on the same level in the hierarchy as the neck.

Failing that, what's the likelihood of being able to transfer all the enveloped weights of one bone to another?

Thanks.

[EricTRocks]

Hey,

To the best of my knowledge there is no way of putting a bone that is the second bone in a 2 bone chain on the same level of the first, kind of defeats the purpose of a chain right?

So I would say that if you are in a situation where you need to break them apart, you can try the 'Break Chain at Bone' option in the skeleton menu, although that is not the best way to control the neck / head.

What is wrong with your current setup? What problems are you having? I don't think there is anything wrong with having a 2 bone chain for neck and head, although it would be smart to ensure you have an FK control setup on it. Typically, they are 2 separate chains from my experience. Hell, they don't even have to be chains.. two null objects work just as good.

Anyway, the last part you ask if there is a way to transfer your weights from one bone to another, the answer is yes. Here is my workflow:

Create two seperate bone chains apart from the one already enveloped, one for the neck, one for the head. They should match the positions of the bones in the single chain you previously enveloped with.

Now, click the mesh and go to Envelope > Set Envelope. Make sure you DO NOT click the reassign weights box on. Now, select the two new bones you created. Note: do not select the 2 new roots, or 2 new effectors. Use the schematic if necessary. Right click to end the pick session.

These new bones are now part of the objects that are evaluated in the envelope operator. Though they have no influence yet.

Open the Netview (alt+5). On the top menu go to Animate > Rigging (left side now) > Transfer Bone weights (#8). In order to use this, you need to select the mesh, then click the run link in the netview. Select the source bone, then the one you want to swap the weights with. Thats it. Just do it for the neck bone too.

Hope that answers your post. Let me know if you have any more questions.

Later,
Eric T.

[4602]

hy
i remembered this from a while back:
http://www.xsibase.com/forum/index.php?board=29;action=display;threadid=23869
haven't used it or looked at the code, so wouldn't know if it works properly. and it is a 2006 plug in, so i'd say test before using it.
4602

edit: misread completely, this will actually split a single bone in 2. sorry about that, hope i might turn useful in some way, however.

[pequod]

Joy!
I used the 'Transfer Bone Weights' script to swap the weights from my existing head (keeping the neck/head chain intact) to a new bone for the head (child of the old head bone).
This allows me to orient constrain the old head bone to the body null, so the head stays level whenever I rotate the torso. But, I now also have the freedom to rotate the head independently using the new weighted head bone.

Thanks Eric.

The 'Split bone' plugin also looks very useful for people like me who don't plan their rigs properly in advance. Thanks for the link Juanf.