You can also achieve the effect by creating two animations in Spine, the one animates the skeleton’s scale X from 1 to 0.001 and another animates the skeleton’s scale X from 0.001 to 1, flip your skeleton in Unity when the first animation is complete, and play the second animation at the end.
Please refer to the following section of the documentation for instructions on how to flip the skeleton:
spine-unity Runtime Documentation: Changing Scale and Flipping a Skeleton
Note: Specifying 0 for the skeleton’s scale in Spine may cause animations to go wrong, so please use a value as close to 0 as possible like 0.01 or 0.001 instead of 0.
