Texture packing weird issue

LakeIshikawa

I have one spine with 2 skins, referencing an image folder.
For some good reasons, I have to export the skeleton together with the atlas, and then export the texture separately from the image folder, without the skeleton.

So I am expecting the texture packer to work exactly in the same way when I export the skeleton (generating the .atlas file), and when I export the image folder for packing only (generating another .atlas and the texture, which should be the same).

Everything works well when there is no skin.
When there is a skin, though, for some reason I find that for some spines the image slots related to the skin are swapped around in the atlas when exported from the image folder.

For example, I have "body" for the normal skin and "body_alt" for the alternative skin, and those 2 images are swapped around in the atlas when I pack with -p from an image folder, compared to when I pack with -e from the skeleton.

How is this possible?

Note: All images in the folder are referenced by the skeleton, there aren't any unused images.

LakeIshikawa

Erika

Hello LakeIshikawa,

LakeIshikawa schrieb
I have to export the skeleton together with the atlas, and then export the texture separately from the image folder, without the skeleton.

The atlas file is there to define the images position in the exported png file. I guess you meant that you export everything the first time (json/skel and atlas as well as png), and then export the images separately with the texture packer again?
You can avoid packing your images altogether if you uncheck the packing option in the export settings if you prefer.

LakeIshikawa schrieb
So I am expecting the texture packer to work exactly in the same way when I export the skeleton (generating the .atlas file), and when I export the image folder for packing only (generating another .atlas and the texture, which should be the same).

Well this isn't necessarily true, depending on the chosen setting, exporting the Spine project may use all the attachments used by the project that have the option checked to be exported and aren't keyed in an animation. On the contrary Texture packer doesn't take this into account, but looks for the folder structure and if there are packing settings present. This in intself could already produce different results.

LakeIshikawa schrieb
When there is a skin, though, for some reason I find that for some spines the image slots related to the skin are swapped around in the atlas when exported from the image folder.

I'm afraid I need clarification on what you need by "spines", if you mean Spine projects that you export using the Spine export, then Spine doesn't attempt to pack images belonging to a skin together but for the best and thighest possible result.
If you want to define which images go in which page of the exported png, then you definitely need to use Texture packer instead.

Here are the two user guide topic that go into more detail about how export and packing work (especially the folder structure section):
Texture Packing - Spine User Guide
Export - Spine User Guide (I'm linking this second page, because you may also be interested in automating these steps using our Command Line interface)