Change root bone for plastic skeleton

[psychoanima]

When you create skeleton with Plastic, first bone that you create is the Root bone which is static - can't be moved in Animate mode. Nice addition to that will be to have an option to change Root bone during animation so it can be used as a lock bone (for a walk cycles, heavy lifting, etc.) Something similar that Pinned Center is supposed to do in Inverse Kinematics mode (suggestion for Inverse Kinematics Pinned Center improvement can be found here: #282)

[Juls3000]

Then -as psychoanima propose for non-plastic skeleton- associate change of root bone to a key frame visible and movable, at least on function editor

[PsmithG]

In all skeletal animation systems I am familiar with, there exists a root bone which is the ultimate parent of the entire skeleton. When the root bone is moved, the entire skeleton moves with it.

If, however, one or more of the child bones is "pinned", it becomes possible to move the rest of the skeletal members relative to that pinned bone, allowing the character's center of gravity to convincingly change over time.

By switching which bone is pinned at any given time, the character's center of gravity can continuously change - as illustrated in a walk that progresses - or an acrobatic maneuver - (a "vault" over an object) - or an action where a character lifts itself by its arms.

This is the simplest, most direct method of producing these animated effects - (as proven by its usage in most character animation software). Why not stick with this proven and simple method?

Greg Smith

[psychoanima]

I am aware of these methods, but OpenToonz is not made with the same logic as the other packages. I like very much how IK pinning is designed in OpenToonz and it will be great to see the same pin functionality in plastic tool. For moving root bone I have no problem as far as I can move Pegs, Tables and Columns with Edit Tool :)

[RodneyBaker]

This feature request could use some research and development to determine what the ideal solution.
At present there doesn't seem to be agreement on a way forward regarding root 'bone' for plastic skeleton.
Translation: Clarification is needed.

[RodneyBaker]

I am curious if an interim change that would help move this feature request forward might be a simpler set of requests.
For instance:

If we can select and delete the current root bone this would (presumably) shift the root to the next available vertex.
In this way we could use current copy/paste methods to duplicate skeletons but then adjust them to have a different root; namely the next vertex down the line with each succeeding deletion of the current root.

Additional (small) changes could then be created to fill in additional gaps in plastic tool capability and to enhance the feature set. This small first step however would potentially provide a means to modify skeletons while changing their root vertex.

Disclaimer: I'm a little biased toward Greg Smith's suggested approach but that is due to past experience with 3D rigging as well as a general thought to keep an eye on standards used commonly between applications.

[psychoanima]

I wonder how hard would be for programmers to enable a root bone to float around, that is, to be unlocked and freely moved. And not only that, but all other bones to respond to root movement, which means when root is moved all plastic bones follows.

And on the other hand, to be able to lock/unlock every possible plastic bone. That gives a hell of a lot flexibility during the animation: foot lock for walk cycles, moving all bones/character at ones if hip as a root bone is being moved, etc.