Is there a way to export a finished animation as an Unity animation ?
See this documentation section on how to bake animations:
spine-unity Runtime Documentation: Skeleton Baking
Note that this is not recommended for runtime use, as the feature set of Unity's skeletal animation system is only a small subset of the features of Spine animations. You can however use the baked animations to gain an approximate preview in Unity which can be scrubbed, and to determine certain timepoints of an animation.
The primary way of previewing Spine animations however is to use the Inspector preview when selecting the
SkeletonDataAsset. If you need a more detailed preview, it is recommended to view the Animation in the Spine Editor.
The problem with Spine animations is that they cannot be controlled on an animation timeline
If you want to preview a Spine animation (the animation assets nested below the skeleton's Mecanim
_Controller asset) in the Animation Window in Unity, you are correct that it currently doesn't display the animation in the Preview window. While we have an issue ticket here regarding this feature, we unfortunately had to put it on hold due to the time necessary to complete it and due to its rather low importance in comparison to other issues.
If you meant that you want to use
SkeletonMecanim with Unity Timeline, just use the Timeline Extension UPM Package:
spine-unity Runtime Documentation: Timeline Extension UPM Package