Hi !
I have a Spine skeleton with 2 animations. The skeleton has an IK Constraint on its leg. In the first animation (idle), the Mix of this Constraint is 100, as I want the leg not to move.
In the second animation, I set on the first frame the Mix of this Constraint to 0, as I want the leg to move, this time.
In Spine Editor, it's working well. But once I export it as JSON and import it in Unity, I have a bug. If I play the Idle before the Push, the leg will not move during the Push, as if the Constraint Mix was still 100 (instead of 0).
It's very consistent when I play my game, but it's more random if I just check the animation in the Unity Inspector (sometimes the bug appears, sometimes no, sometime I need to reimport the Skeleton to trigger it.)
I have made a video to show the issue :
As I said in the end of the video, there is a weird workaround: If, instead of a Constraint Mix of 0, I set it to "0.1", for example, it will work as intended.
It's why for me, it's an issue similar to the one described here: https://esotericsoftware.com/forum/d/26897-exporting-animation-with-physics-constraints-keyframes-breaks-the-contraint, but probably in the Unity side.
For an easier repro, here is my Spine project and Unity export: https://www.studiochahut.com/dl/SpineDogBug.zip
Runtime information
Tell us your Spine Runtimes version.
4.2.42
