Question Create SpriteLibraryAsset by Scripts

Hello, I'm trying to create a SpriteLibraryAsset pipeline, since creating one by assigning sprites to each category is really time consuming. It would be a lot more easier if I can just create sprite library assets and add sprites into the category according to sprite name or folder name it belongs to.

Here's what I tried:

Code (CSharp):

1. public class SpriteLibraryAssetFactory : EditorWindow
2. {
3.     [MenuItem("Window/Example")]
4.     public static void ShowWindow()
5.     {
6.         GetWindow<SpriteLibraryAssetFactory>();
7.     }
8.  
9.     private void OnGUI()
10.     {
11.         if (GUILayout.Button("Create"))
12.         {
13.             var sprites = ResourcesFolderLoader.LoadAllSpritesInDefault();
14.            
15.             var asset = ScriptableObject.CreateInstance<SpriteLibraryAsset>();
16.             foreach (var sprite in sprites)
17.             {
18.                 asset.AddCategoryLabel(sprite, "test", "test2");
19.             }
20.             AssetDatabase.CreateAsset(asset, "Assets/test.spriteLib");
21.             AssetDatabase.SaveAssets();
22.            
23.         }
24.     }
25.  
26. }
27.  

If I try to use AssetDatabase.CreateAsset(so, "Assets/test.asset"); to generate ScriptableObject, this is fine. And since SpriteLibraryAsset is derived from ScriptableObject, I suppose this should work. However, I encountered these error:

Question now is what is the correct way to create SpriteLibraryAsset by code. Any documentation, examples or explanations is appreciated! Thanks.

 

Did you get anywhere with this? I'm trying to get started on a similar project myself.

 

My current setup for a top down RPG has a sprite library asset used to have matching animations across a variety of animations. The player character sprites, the clothing/armor sprites, the weapon sprites, the npc sprites, all each have their own sprite library asset with identical categories and all use the same animator, so I only have to set up a type of animation once. I expect to have quite a few different character sprites and a much higher quantity of different npcs, enemies, different kinds of armor and clothes, etc, and while I can manually create a sprite library asset for each one with a preset, adding a couple dozen sprite slices to the correct slots in the library is time consuming and error prone. Ideally, I'd like to have an automated workflow such that I can drop a sprite image into a watched directory, and on import have it automatically sliced and create a new library (if one doesn't exist) and add its sprites to the correct categories in the correct order, based on a consistent slicing layout and filename conventions. Then I can just create a new instance of a prefab and apply the different library to it and all the animations just work.

 

me too ....

 

I am also trying to use AddCategoryLabel to create, expand, and evolve libraries as new assets are imported. We are trying to use naming conventions to specify which library and category a sprite goes into so we can then use sprite swapping for different eyes, hairstyles, clothing, etc.

We are navigating a ton of complexity here. For instance, when a hairstyle changes I need to swap many sprites at once since I have several views of character, front, back, side, etc. And each hairstyle might have a foreground a background sprite with each view.

I keep encountering things within Unity that just seem to be developed in a way that doesn't anticipate an iterative, prototyping mindset. If I can do it in the editor, I should be able to do it in code, right? I find it REALLY odd that this isn't the case here.

 

I too have this issue, and wish there was a way to save the SpriteLibraryAsset created in the edit-time to my Assets folder.

I have many different player character sprites, which use the same animation. So in order not to drag and drop >100 individual sprites, I wanted to create a script that runs during edit-time, which creates the SpriteLibraryAsset for each character, however even if there was functionality to save it in edit-time, I can't find the "Main Library" attribute, which would allow animations to be reused...

Would greatly appreciate if there was code support for saving the SpriteLibraryAsset in edit-time into Assets folder, as well as setting the "Main Library" attribute through code.

 

This is also a feature that would make our lives easier. I am currently building a rig generator to streamline the rig creation process for our artists and designers and would like to automatically generate and fill the sprite libraries based on a regex match of sprite assets.

We've already modified the 2D animation package (the new warning about an invalid signature in packages should be able to be disabled) to add in things like skeleton inheritance (another feature that would be useful) and expose a lot of the useful internals to the normal editor.

The new asset mapped to .spriteLib is an internal SpriteLibrarySourceAsset, so in the meantime (if you're willing to use reflection or modify the package) you can use that. The SpriteLibUpgrader has some code showing how to serialize a new SpriteLibrarySourceAsset.

 

I understand the pattern you're going for, but the difference between the SpriteLibrarySourceAsset's and, say, a model or a PNG is that SpriteLibrarySourceAsset is unique to Unity. There are plenty of ways to create, edit, modify and import PNG's, or even models, in code. Simply moving them into the project directory and updating the asset database lets you load/reload them. Effectively, modifying these types of source assets is not 'internal' functionality. Unity does not need to provide an API for these files because plenty of API's already exist.

To only way to achieve a similar result with the SpriteLibrarySourceAsset (without breaking open the internals as we did) is to save a new file based on an existing template. The example code you gave creates an asset that prompts the user to "Upgrade" to the new type of SpriteLibrary when it is clicked on. This experience is not ideal.

SpriteLibrarySourceAsset is itself a ScriptableObject, ScriptableObjects are most easily edited through Unity's codebase, so keeping it internal with no API to create or edit instances of this source asset is artificially limiting in ways that the other types of source assets are not.

If what you're ultimately trying to do is totally prevent users from creating SpriteLibrarySourceAsset's at runtime, then a simple editor-only API with SpriteLibraryAsset that lets users stage and then "Commit" changes to it would work. This is essentially what your editor code already does when upgrading assets.

 

Functionality-wise? Not much, other than the fact that the user may give up whatever performance benefits there are of using SpriteLibrarySourceAsset instead.

But at its core it seems very arbitrary and inconsistent that there needs to be a difference between user-generated Sprite Libraries from code and Libraries generated with a click of a button in the Unity Editor. Maybe I just have not encountered them yet, but I am unaware of any other asset in Unity behaving the same way. (Having the source asset be a ScriptableObject and preventing the user from creating said ScriptableObject).

If we ever decided to release an asset store package of the powerful rig generator we are building, this would just be another annoying issue to work-around using reflection or some other unnecessarily hacky method.

 

That makes the proposed solution better, but also begs the question of why SpriteLibrarySourceAsset's were even needed in the first place?
If SpriteLibrarySourceAsset led to increased performance and functionality, then the user should have the ability to create them. In my opinion, this includes the behavior of not committing any changes immediately. (Speaking of, can you even permanently modify a SpriteLibrarySourceAsset-backed SpriteLibrary with the existing API? Or will no changes ever be written to disk?).
If SpriteLibrarySourceAsset doesn't lead to increased performance and functionality, then why does it exist except to cause confusion when users try to create a SpriteLibrary asset?

Is it simply to conform to a design pattern used within Unity that may lead to changes in some future update? Is it to prevent unintended modification of the serialized asset?

I can definitely see there being a lot of user confusion between libraries saved as .asset and libraries saved as .spriteLib. Especially if you are working on a large team with some artists creating libraries from the editor and others using a custom tool to generate them.

 

If you save a SpriteLibrary like you showcased in your SpriteLibCreator code, it this is what it looks like in the editor:

Notice how it is simply a "Sprite Library Asset". It is not a "SpriteLibrarySource Asset imported as a SpriteLibraryAsset" like what happens when you create a new SpriteLibrary through the menu, as seen here:


The regular "SpriteLibraryAsset" does not have the "Main Library/Override" functionality of the SpriteLibrarySourceAssets either.

We want to be able to create a tool that generates sprite library assets and fills them up with sprites at editor time. We want the Sprite Libraries created through our code to be no different than the sprite libraries created by clicking the menu in the editor. We want to be able to do this without breaking into the Animation package and forcing it to give us access to its internals.

 

Sorry to necro this post, but just to add to the already large number of users discussing this, I have over 300 individual Textures all with identical signatures (12 sub-asset sprites with identical dimensions). All sprites should have an associated Sprite Library Asset that is populated with each sprite so that a Sprite Resolver can be used to animate these characters without the need to create new animations for each and every sprite.

To speed up the creation, all I'm looking to do is once I click a button in a custom editor I have created, it takes the selected Texture2D that matches all of the above conditions, creates a new Sprite Library Asset, sets the main library asset to one I have set up, populates each category with the corresponding sprites and saves it. From the outset it sounds like a simple task and one that I would have expected to have been possible given the moddability of the Unity Editor.

I understand the need to have separation between the runtime assets and the source assets/importers, but I'm not sure I follow this arbitrary internal decision to lock off the entire class and make it impossible to create workflow, time saving automation tools, because after reading through this topic all that has become apparent to me is that the official response is, "get used to it, enjoy the monotonous task of manually creating child library assets for each of your sprites!"

 

So the reason why many people want this interface is because:
Imagine we have hundred PSB files, each contain a character which has same body parts with same names and share a same skeleton. So if we could have this interface, then we don't have to add those sprites manually and copy all the same names, that my friend, would save countless time.

So we would love to have this interface for save the change to SpriteLibraryAsset Source File by editor scripts.

Here is what I have tried this afternoon(Wish I know that sooner so I don't have to spent who afternoon try to find the solution...):
So after calling

Code (CSharp):

1. SpriteLibraryAsset.AddCategoryLabel

and

Code (CSharp):

1. SpriteLibrary.AddOverride

and then calling:

Code (CSharp):

1.         void SaveSpriteLibraryAsset(SpriteLibraryAsset spriteLibraryAsset)
2.         {
3.             EditorUtility.SetDirty(spriteLibraryAsset);
4.             AssetDatabase.SaveAssets();
5.             AssetDatabase.Refresh();
6.         }
7.         void SaveOnDisk(SpriteLibraryAsset spriteLibraryAsset)
8.         {
9.             // MyScriptableObject : ScriptableObject
10.             SpriteLibraryAsset asset = ScriptableObject.CreateInstance<SpriteLibraryAsset>();
11.             AssetDatabase.CreateAsset(asset, AssetDatabase.GenerateUniqueAssetPath("Assets/" + "1.asset"));
12.             AssetDatabase.SaveAssets();
13.             AssetDatabase.Refresh();
14.             EditorUtility.SetDirty(asset);
15.         }

And SpriteLibraryAsset Source File is not modified, now I know why, because it's not supported.....

Anyway, have a good day sir, hope this kind of interface could be added in the future update. Cheers!

 

@Ted_Wikman
Does this actually work though? If I use this code but to add sprites to an existing category in an existing sprite library asset, the UI in the inspector doesn't refresh to show the sprite is there. I can see it is there (temporarily) in code though. But as soon as I restart Unity the sprite is gone as if I never added it via code.

Code (CSharp):

1. spriteLibrary.AddCategoryLabel(sprite, category, id);
2. spriteLibrary.AddCategoryLabel(icon, category, $"{id}_icon");
3. EditorUtility.SetDirty(spriteLibrary);
4. AssetDatabase.SaveAssets();
5. AssetDatabase.Refresh();

 

I guess I don't know the difference other than the prefix. I just created them using Assets > Create > 2D > Sprite Library Asset. That creates a .spritelib so I guess I'm using the wrong one? How do I create the .asset and will it let me do the same thing as the .spritelib?

Or am I just using the wrong type in code?

Code (CSharp):

1. var spriteLibrary = Resources.Load<SpriteLibraryAsset>($"{category}SpriteLibrary");

 

So what can I do to make this work? If I create a sprite library asset through the inspector it creates the .spritelib file, not an asset file. I have multiple sprite libraries that all contain a decent number of sprites. Hopefully I don't have to redo them all.

 

Can we modify .spriteLib files with a script yet?

If the Sprite Library Editor exists we should be able to do this. But I don't see any available APIs. I need this.

The difference between these two asset types is still not apparent in the Editor. Only by being involved in this thread would someone know this. .spriteLib files are even labeled "(Sprite Library Asset)" in the Editor.

A Sprite Library Asset (.asset) doesn't feel like other .asset files. When I change an asset I expect it to persist in the AssetDatabase. I guess it does, but it only feels to be persisting in that Sprite Library component. Also, assets are supposed to live in the Project Window, but I only see the .spriteLib asset there.

This is REALLY CONFUSING and frustrating.

 

Thanks so much!

I'll give this a try. This could be a nice stopgap.

Also worth noting is that scripted Sprite Library component changes persist through Domain Reloads for me but not through Editor closing and opening. This is another bizarre behavior for me. This will be less of an issue once I can save a .spriteLib file but I still may want to have differences in the local Sprite Library component.

This system really could use another round of improvement soon.

 

Also, whoever created this framework should really get some mentorship on developer UX and/or API design. Either that or be given the time to focus on DevX more. Several obvious improvements if you take the effort/focus to polish this.

 

Hmm ... looks like I am currently calling SetDirty on my Sprite Libary Asset (.asset) and not the Sprite Library component.

I'll give the Sprite Library a try, thank you.

 

I'm answering in the thread because I'm searching for quite the same thing here:

That is exactly what I'm searching for, since at the moment I can do all of this using Sprite Library but I have to drag n drop every single frame on at a time. It would be good just to be able to select multiple of them and drag them in a category in order to swap every sprite coming from the "master/template" library with the ones I selected.

 

This is also my use case. I have to drag each sprite one by one in the editor which takes forever. Also the list view in the "Labels" view is partially broken and does not detect changes if it's in list mode. I tried the last two days to write a replacement where I can drag multiple sprites at once (40 labels -> 40 sprites and they would assign one by one) and now I found this thread sayin one cannot save a spritelib through code ;(
It would be really nice if we can either drag multiple sprites or modify the libs in code.

 

While the helper class above is a usable stopgap, I am finding it to be far from ideal.

We need a better API for this, people need to be able to selectively save one Sprite at a time to the source asset via script.

This feature set needs a good bit more evolution in my opinion.

For example, look at this UI for the Sprite Library component.

 

Is 2D Animation's "modify Sprite Library Asset through code" something being worked on or currently available (9.0.4)? I don't mind manually creating the sprite library asset scriptable object, but I would really appreciate if I can modify the contents of the sprite library asset through code.