This thread has been created to continue the discussion started here on this forum thread under a more suitable topic name:
Unity Log for null animations
I've opened a properly named thread here so that everyone who is interested in this topic can participate.

foriero wrote
Harald, is there a reason why spine animations assets are not grouped into one master asset? We have thousands of animations and if I use what you suggest then our project have thousands of files added. :-( Moreover if you group them into master asset it can simply live next to skeleton data file. And if people need to do their own assets they will create custom master asset and add there SpineAnimationAsset and reference them from there.

What I propose have SpineAnimationAssetGroup and SpineAnimationAsset. Generate it automatically when importing. Since this way we have only one file it is not a problem to do so. Does it make sense?

Thanks for sharing your thoughts. I'm answering here instead of replying to your mails so that others can participate in the discussion as well.

foriero wrote
Didn't know about AnimationRefereceAsset.

Oh, ok, I assume the example scene Spine Examples/Getting Started/3 Controlling Animation Continued didn't exist when you started using spine-unity years ago, as it demonstrates it rather early in the list of example scenes.

foriero wrote
Much cleaner and only one file in repository instead of thousands of individual animation references files.
[..]
Harald, is there a reason why spine animations assets are not grouped into one master asset? We have thousands of animations and if I use what you suggest then our project have thousands of files added. :-( Moreover if you group them into master asset it can simply live next to skeleton data file. And if people need to do their own assets they will create custom master asset and add there SpineAnimationAsset and reference them from there.

The main reason is that these assets have already been generated this way in earlier spine-unity versions, and changing the structure always comes with additional effort to ensure automatic updates without breaking existing projects. Unfortunately there are currently too many far more important tickets remaining, whereas users would not benefit much from this feature (subassets at a single asset file vs. assets in a subfolder).

foriero wrote
What I propose have SpineAnimationAssetGroup and SpineAnimationAsset. Generate it automatically when importing. Since this way we have only one file it is not a problem to do so. Does it make sense?

foriero via email wrote
If this bank can be created and updated automatically I think it will help a lot the animation workflow in Unity.

It seems as if you have reimplemented part of the functionality already provided by SkeletonData.
When I suggested using the SetAnimation() overload variant taking the Animation object parameter I mainy meant that you should be caching and re-using an Animation object, which SkeletonData.FindAnimation(animationName) returns instead of implicitly calling FindAnimation() every time.

So I would suggest using the name strings to setup your assets, but in your code you should resolve them to a cached Animation object once at e.g. Start(). I currently don't really see any benefit in a SpineAnimationAssetGroup class with additional methods, but if you have some other use case in mind, please let us know.

@foriero Answering the email here again so that others benefit from the discussion.

Having seen your email about your project structure and your problems with it, I would summarize your issues as follows (if anything is wrong, please lmk):
1) You have many/all skeletons placed in a flat directory instead of in subdirectories per skeleton.
2) When selecting Create Animation Reference Assets all generated AnimationReferenceAssets are placed in the directory ReferenceAssets which is now shared by multiple skeletons, they all dump their reference assets in this directory.
3) You prefer having a single asset file with many nested AnimationReferenceAssets as sub-assets, instead of many separate AnimationReferenceAsset files.
4) When you have an AnimationReferenceAsset property in the Inspector and are clicking the asset selector next to the property, it lists all AnimationReferenceAssets in the project, instead of only listing assets suitable for a specific skeleton.

Now about answers to those issues:

1) You have many/all skeletons placed in a flat directory instead of in subdirectories per skeleton.

Why are you placing all your skeletons in a single directory and don't create a subdirectory for each one? This would automatically solve the problem of having all AnimationReferenceAssets put into a single common directory.

2) When selecting Create Animation Reference Assets all generated AnimationReferenceAssets are placed in the directory ReferenceAssets which is now shared by multiple skeletons, they all dump their reference assets in this directory.

Admittedly this is not good at all, the directory should either a) be named containing the skeleton name to have a unique sub folder, or at least allow and track renaming after creation of the folder (currently it generates a new directory ReferenceAssets when selecting Create Animation Reference Assets and they already exist in a renamed folder).

3) You prefer having a single asset file with many nested AnimationReferenceAssets as sub-assets, instead of many separate AnimationReferenceAsset files.

This is admittedly perhaps cleaner in your git/svn commit log. I would also favour such a structure, but automatic transition needs to be implemented and tested properly.

As you've sent some code via email, I would need to check this, but currently I'm afraid we don't have time yet for this rather low-priority feature.

4) When you have an AnimationReferenceAsset property in the Inspector and are clicking the asset selector next to the property, it lists all AnimationReferenceAssets in the project, instead of only listing assets suitable for a specific skeleton.

This is indeed not optimal. While Unity's animation clips selection is behaving similarly bad, that should not be an excuse to have a bad solution, too.

Drag-and-drop of the AnimationReferenceAsset from the folder where all AnimationReferenceAssets of a single skeleton are (see [1]) should currently be the workflow which automatically "limits" the number of animation reference assets to choose from. Nevertheless, a clean and easy solution for clicking the asset selector and getting listed only suitable reference assets would be nice.

I have opened this issue ticket here:
https://github.com/EsotericSoftware/spine-runtimes/issues/1940

It would be nice if there is some discussion about whether other users also face such issues, and how they might already be tackled efficiently. So everyone: Please share your thoughts and opinions here if you've encountered problems (or created workarounds / solutions) in regards to using AnimationReferenceAssets, or how you deal with them efficiently and avoid any issues in the first place. Thanks in advance! :nerd: