Export only one skin programmaticaly

wighawag

Hi all,

Still new to spine but wondering if there is a way to export a project that contains many skins so that the resulting export json/binary only contains one skin (like if we could basically export the skin view screen and pick what set of skin we want)
and that any image not used would not be included in the atlas neither.

the use case for that is that the project file is expected to contains many combination for which I only want to select a few and that each export should be independent of the information needed to pick that selection.
So that each export is a self contain project with only one skin.

One way I could see it working would be to export and then remove any ref to the non-desired skin element, but that involved quite a bit. Also the atlas would require special attention.

I can see some previous conversation around similar topic (see links below) but it seems spine do not support such simplified export, am I right?

I tried to export with command line but not file is created.

Selective Exporting

Any other idea to solve the issue ? any way to programmticaly acces spine editor runtime data. Like if I could write a plugin that programmatically uncheck export for skins, I could potentially achieve that, but not sure if it will scale for my use case as I need thousands of exports

Nate

As you may have seen in the linked threads, Spine isn't designed to export a skeleton partially (for example, with a subset of skins). There shouldn't normally be a need to do this. Spine exports your entire skeleton as one file. The size of this, including all your skins, is unlikely to be a problem. At runtime you can load a subset of your images, if needed. There is no need to export only part of your skeleton solely because you will only load a subset of your images. The images and skeleton data are completely separate by design.

wighawag

Hi @Nate, thanks for your answer.

My use case is more a distribution / licensing issue than a performance one. I ideally want to distribute single designs where the extra skin are not wanted. The user getting the file should not have access to the other skin. Ideally I even want these exported file to not have the concept of swapable skin where the only skin left is the default skin, so that when the user want to use that file, there is no skin name to pick.

In that case would you recommend I modify the exported file so that extra skin info is removed and the wanted skin become the default skin?
Similarly for the atlas, I could regenerate the png and the atlas so that any non-used asset is removed.

Nate

I think for that use case it would make sense to process the JSON data, eg to remove all the skins except one. If you want to use Java, it could be done similar to this tool:
https://github.com/EsotericSoftware/spine-runtimes/blob/4.0/spine-libgdx/spine-skeletonviewer/src/com/esotericsoftware/spine/JsonRollback.java

Yep, for the atlas it's just a matter of packing an atlas with only the images you want.

wighawag

Thanks @Nate that's very useful!

If I want a binary export (and do that Programmatically for thousands of export), if I read correctly the doc I should be able to

Programmatically export json (via cmdline spine)
use my tool to create a modified json without the skin to be discarded for each of the thousands
Programmatically import each json (via cmdline spine)
Programmatically export each binary (via cmdline spine)

Or am I missing something?

Nate

I think that is the easiest way to get binary, yes. You should be able to specify a JSON file instead of a project file, so you cam convert JSON to binary like this:

spine -i your.json -o output/folder -e binary

Note the output path is a folder because the JSON is converted to a project, then the project exported to a folder as normal (since it could have multiple skeletons).

wighawag

Great! thanks @Nate!