To add animations to a sprite in Unity that's already using Spine, you don't necessarily have to re-export the entire project from Spine. Instead, you can manipulate the AnimationState in Unity to add or change animations programmatically. The Spine-Unity runtime provides a robust API for controlling animations, including adding new animations to a track, blending animations, and more.

For example, to set a new animation, you can use the SetAnimation method on the AnimationState object associated with your Spine GameObject. Here's a basic example:

skeletonAnimation.AnimationState.SetAnimation(0, "new_animation_name", loop: true);

This code assumes you have a reference to the SkeletonAnimation component named skeletonAnimation and replaces the current animation on track 0 with "new_animation_name", setting it to loop.

If you're looking to add an animation on top of the existing one (e.g., to play a jump animation while running), you can use the AddAnimation method instead:

skeletonAnimation.AnimationState.AddAnimation(0, "jump_animation", false, delay: 0);

This adds "jump_animation" to be played immediately after the current animation on track 0 without looping.

Remember, these methods require the animation names as strings, which must match exactly with the names used in your Spine project. If you're frequently changing animations, consider using AnimationReferenceAsset for a more robust solution, as mentioned in the Spine-Unity documentation.

For more detailed control over animations, including event handling and mixing, refer to the Spine-Unity Runtime Documentation.

sh0ckwave_99 Spinebot's answer above is probably off the subject of your question, but since you are new to Spine, I thought I'd leave it here in case some of the information might be useful.

I saw that all of the current animations on my sprite are exported as attached animation states.

I'm afraid I don't understand what you mean by that. I suspect that you are referring to the skeleton as Sprite, since using Spine to add animation to Sprite sounds a bit odd as a connection.

If you just want to add or change the animations that the skeleton that you have already imported into Unity has, you don't need to repack the textures, just replace the .json or .skel.bytes files in your file explorer and they can be updated.

I would appreciate a more detailed explanation if my response seems to be out of line with what you want to do.