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  • Explain physics behaviour please

Attaching Spine project and video explaining behaviour

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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 Chain scale:

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In that case I like to organize the bones like this:

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    Nate yes but then physics won't work like a chain. And honestly apart from that icon i never saw any problem 😃

    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.

      Nate I understood 17% of this message

      Will revisit maybe later to increase that number

      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.

        Nate that what I actually got from the first message 😃 but with that description i should have seen the issue more often than 0. Is it noticable? Something like Jumping ? Or just scales are off a bit

        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.