Attaching Spine project and video explaining behaviour
Explain physics behaviour please
omg remove this post I had compensation enabled so embarrassed
Haha, no we must document this forever!
Note that the warning icon on your path is because the constrained bones for your path constraint are nested and you are using Image removed due to the lack of support for HTTPS. | Show Anyway Image removed due to the lack of support for HTTPS. | Show AnywayChain scale
:
In that case I like to organize the bones like this:
TL;DR: The path constraint won't work incorrectly with Chain scale
if the constrained bones are nested AND another constraint triggers an update for those bones (by also constraining them or any of their parents).
For path constraint, as a performance enhancement, all constrained bone lengths are computed before any constrained bones are scaled by Chain scale
mode. That scaling is done by adjusting each bone's world transform directly, without the constrained bones inheriting scale from parents that are also constrained bones that Chain scale
mode scales. That results in constrained bones that are each scaled as expected, but their "applied local transform" values computed from the world transform DO consider the parent world transform. This makes the applied transform for the nested bones incorrect.
The applied transform stores the local transform that is the result of applying the constraint. It is stored separately from the unconstrained local transform and is used if another constraint is applied. So, if another constraint is applied that causes the bones along the path to be updated using their incorrect applied transform, those bones won't be correct.
There's even a TL;DR! I'll try again: if you have a path constraint with
Chain scale
and the constrained bones are nested, then if another constraint affects those constrained bones or any of their parents, you won't like the results.
We have a repro case somewhere, I'd have to dig it up. I think it's pretty noticeable, the bones won't follow the path.