Merging a single atlas file for multiple skeletons

Yomao

Example: A Spine project has two skeleton animations: F000 and F001. When exporting with the "single atlas" option, the output files are: F000.png, F000.atlas, F000.json, and F001.json. When I try to import F000.json and F001.json into the engine, it prompts me to add F000.atlas and F001.atlas, even though there's only one atlas file: F000.atlas. As a workaround, I copy F000.atlas and rename it to F001.atlas, creating two .atlas files, which allows me to upload them to the engine.

Problem: This workaround means the uploaded atlas files are identical, and each JSON file only uses a portion of the data. I'm forced to upload duplicate data to the engine (it's impractical to manually remove the redundant data), resulting in unnecessary data clutter in the engine.

How can I solve this? How can I generate separate atlas files for each skeleton animation without including redundant data?

Spinebot

To solve the issue of having to duplicate atlas files for multiple skeletons, you can use the Spine Texture Packer to create a single atlas that contains images for both skeletons. When exporting your skeletons, ensure that you do not create separate atlases for each skeleton. Instead, export the skeletons without creating an atlas, and then use the Texture Packer to pack all the images into a single atlas. This way, you can have one atlas file that both JSON files reference, avoiding the need to duplicate atlas files. Make sure that the image paths in the atlas file match the paths used in the skeleton data files so that they can be correctly imported together.

Yomao

When I operate according to the above method, I feel that the AI robot is replying to me randomly, because this solution is not reasonable at all.

Misaki

Yomao Spinebot's answer doesn't directly address your question, so in that sense it's not ideal. However, it's not entirely wrong either. You seem to be manually duplicating atlas files, but that's actually unnecessary.

For cases like yours, where the runtime warns about missing corresponding atlases during import, there's spine-unity, for example. With spine-unity, if you first select “Import without atlases” to import the skeleton data, then later set an Atlas Asset in the Skeleton Data Asset's Atlas section, it should load correctly as long as the paths to each image described within the atlas file match those held by the skeleton data:

Skeleton Data Asset immediately after import:

After manually adding the corresponding Atlas Asset:

Similarly, in other runtimes, you can specify the corresponding atlas file either through the GUI or via code. If you want to know the method for the runtime you're using, please tell us which runtime you're using.

Yomao

Misaki Thanks for your reply. This reply did solve part of my problem, but not all, because my core problem is: when importing atlas data into the engine, the atlas file has no redundant data. It has a one-to-one correspondence with its json, and there is no related data of other bones.

Misaki

Yomao I may not fully understand your issue, but perhaps you simply want separate atlas files when exporting from Spine? If so, select Atlas per skeleton in the export settings window:

Or perhaps your ideal setup is having unified texture atlas pages for both skeletons, but separate .atlas files prepared for each skeleton? Is there a specific reason you'd want to do that? Even if you separate the atlas files, the entire texture atlas page will still be loaded, so there's virtually no difference in loading performance. Please tell us in detail about the state you wish to achieve.

Yomao

perhaps your ideal setup is having unified texture atlas pages for both skeletons, but separate .atlas files prepared for each skeleton?

Yes, that's what I hope.
I know there is no impact on performance, but I hope that the atlas file does not have redundant data

Misaki

Yomao Hmm, I think it depends on how you define 'redundant'. In my opinion, it makes sense for a single .atlas file to contain information about all the regions included in the texture atlas pages. Conversely, a file that only contains information about some regions on the corresponding texture atlas page seems incomplete and odd to me.

The main reason for combining multiple skeleton texture atlas pages into one is that these skeletons almost always appear together in the game. However, if you're combining textures for skeletons that appear in completely different scenes into a single texture atlas and feel that including information for areas used by only one skeleton is redundant, consolidating the texture atlas page itself would not be ideal.
Why are you combining the texture atlas pages for those skeletons into one?