Hi guys,

We're trying to implement a character system using Unity and Spine 4beta. The plan is to have an undressed body only, and lots of outfits for it (100s).

The simplest way would be to of course to create all outfits as skins for the body, but doing it the naive way would have us load all geometry / textures into memory, both of which would not be small. I went over similar posts in the forum, but would like to go over some ideas I have in order to help me avoid time trying to implement dead ends.

1) The first idea I had was to export the body as well as each outfit as a separate character (that means lots of assets of type SkeletonDataAsset). I tried quick prototype, then load body and an outfit to Unity and create a new skin for the body, but the outfit does not show. Is there some requirement for Skin to be only created from the same SkeletonDataAsset? I did something like this:

public SkeletonDataAsset Body;
public SkeletonDataAsset Outfit;

SkeletonAnimation _bodySkeletonAnimation = SkeletonAnimation.NewSkeletonAnimationGameObject(Body);
var customSkin = new Skin("custom-skin");
var outfitSkeletonData = Outfit.GetSkeletonData(true);
var outfitSkin = outfitSkeletonData.DefaultSkin;

// add whole skin
customSkin.AddSkin(outfitSkin);

// or add individual attachments (I tried both options)
foreach (var attachement in outfitSkin.Attachments)
{
      customSkin.SetAttachment(attachement.SlotIndex, attachement.Name, attachement.Attachment);
}

 _bodySkeletonAnimation.Skeleton.SetSkin(customSkin);
 _bodySkeletonAnimation.Skeleton.SetSlotsToSetupPose();

Note that skeletons in both files match (completely or mostly), so I was assuming at least some outfit parts would show.

Should this work or not? Alternatively, is there a way to make it work? Can I at runtime clone skin parts from the outfit to the body and create new skin after that or anything similar?

2) My alternative solution is more along the lines mentioned on the forum here. Create a single character, and create all outfits as skins. Have textures in folders, so that separate atlas is created for each outfit. Then before the build / bundle creation, I thought I'd replace the link to the texture by either null or some dummy 4x4 pixels texture. This way when I load SkeletonDataAsset, large textures won't load. Then I'll have to implement custom atlas loader, load the atlas texture and connect it to material .. is there some example on how to do this part please?
The disadvantage here is that I need to load whole SkeletonDataAsset, which contains the meshes and some other data for all outfits, and I suspect this file will not be tiny. Can this be stores as binary to avoid parsing cost at least perhaps?

I would prefer option 1 if possible, but option 2 is likely acceptable as well. Any other good option here?

Thanks so much!

Hi Harald,

Thanks for getting back to me, much appreciated. I tried the case you mentioned, and indeed that works.I suspect the issue with my data file perhaps comes from slots not matching perfectly.

As an example, the body can have these in this order:

"slots": [
   { "name": "footR", "bone": "P_FootR", "attachment": "Body/footR" },
   { "name": "shinR", "bone": "P_KneeR", "attachment": "Body/shinR" },
        ...  some more here
]

and the outfit would have just two:

"slots": [
   { "name": "pantLegR", "bone": "P_hips", "attachment": "Outfit/pantLegR" },
   { "name": "footR", "bone": "P_FootR", "attachment": "Outfit/footL" },
]

Two observations:

1. the slots are not in the same order .. and so slot index does not match. This somehow seems important, as even this function uses slot index:
   customSkin.SetAttachment(attachement.SlotIndex, attachement.Name, attachement.Attachment);

2. the names of attachments don't match .. but I assume those don't have to?

So is my issue the fact that the slot names are not in the same positions in the slots arrays? I've noticed you have the SkinKey consisting of slot index and a name (slot name I assume, or is it attachment name? This is unclear to me).

In the ideal case I would have the body containing lots of slots. And each outfit would contain a subset of these slots, in any order. Would this not be all needed to match them up? How strict does the number of slots and their order need to be for this to work?

Thanks again.

Hi Harald,

That makes perfect sense, but the create skin is still not showing. I emailed you the small repro project to the email you've given me.
For reference and benefit of others, here's the code I've tried:

public class Root : MonoBehaviour
{
    public SkeletonDataAsset Body;
    SkeletonAnimation _bodySkeletonAnimation;

public SkeletonDataAsset Outfit;

void Start()
{
    _bodySkeletonAnimation = SkeletonAnimation.NewSkeletonAnimationGameObject(Body);
    var bodySkeletonData = Body.GetSkeletonData(true);

    var outfitSkeletonData = Outfit.GetSkeletonData(true);
    var outfitSkin = outfitSkeletonData.DefaultSkin;

    var customSkin = new Skin("custom-skin");

    foreach (var attachement in outfitSkin.Attachments)
    {
        var slotIndex = attachement.SlotIndex;
        var slotName = outfitSkeletonData.Slots.Items[slotIndex].Name;
        int bodySlotIndex = bodySkeletonData.FindSlotIndex(slotName);

        if (bodySlotIndex >= 0)
        {
            Debug.Log("attaching " + attachement.Name + " to slot index " + bodySlotIndex + ", slotName: " + slotName + ", outfit slot index: " + slotIndex);
            customSkin.SetAttachment(bodySlotIndex, slotName, attachement.Attachment);
        }
    }

    _bodySkeletonAnimation.Skeleton.SetSkin(customSkin);
    _bodySkeletonAnimation.Skeleton.SetSlotsToSetupPose();

    _bodySkeletonAnimation.AnimationState.Apply(_bodySkeletonAnimation.Skeleton);
}
}

Hi Harald,

Thanks for this. I agree some slots are missing, and it's expected those attachment do not get attached.
But why are the attachments for existing matching slots not getting attached. I log out the matching slots that exist and I try to attach to it, but it does not render. Example of the log:

attaching JuliaArmor/footL to slot index 0, slotName: footR, outfit slot index: 1

Here is the slot on the body (from Julia_bdy_noX.json) - it's currently at index 0:

"slots": [
   { "name": "footR", "bone": "P_FootR", "attachment": "JuliaNude/footR" },
        ....

Here is the same slot on the outfit (Julia_Armor_noX.json) - slot as index 1 (that is ok as you mentioned), attached to the bone of the same name P_FootR (but this likely does not matter)

"slots": [
   { "name": "pantLegR", "bone": "P_hips", "attachment": "JuliaArmor/pantLegR" },
   { "name": "footR", "bone": "P_FootR", "attachment": "JuliaArmor/footL" },

and here is the attachement on the outfit, which it's referencing.

"footL": {
   "JuliaArmor/footL": {
      "type": "mesh",

I would expect some attaachements from the outfit to show up on the body (log has about 10 valid matches), but none do .. The scene only has a single draw call (using body texture), and no draw call using outfit texture.

Thanks for all the help so far. I got the prototype to an acceptable state, and now I'm exploring the other option, where in the prefabs I strip out the textures (and replace them by 1 pixel white textures). This bit works, and when I load the character at runtime, all is white as expected and no large textures are loaded.

I need to load those original large textures or materials with them at runtime on demand, when I need to use a specific skin. And I'm not sure where to find the materials / textures that are used at runtime, so that I can replace them / swap textures on them. I see that SpineAtlasAsset class stores an array of materials .. but how do I get to its instance at runtime, from the SkeletonData / SkeletonDataAsset?

Hi .. Thanks for that, yes I've seen those, and got this working. So I can at startup load all textures and set them up, and the character renders correctly.

But I am trying to do this on demand. Somewhere later I call:

	[code]Skin srcSkin = bodySkeletonData.FindSkin(name);[/code]

and before this I need to load the textures for this skin. So from the skin name I need to go to a specific material or materials inside the SpineAtlasAsset.
I looked at how FindSkin works .. and followed it to Skin class, and from there to SkinEntry and Attachment classes, and from there to MeshAttachment and RegionAttachment, but don't see a way to find out which material I need to load.

And I got it to work .. loading textures on demand when adding skin, and all seems to work. Thanks for your help.
At some point when your solution is ready, we'll probably considering switching to it .. but for now, this works well. What is the ETA for the feature? (within couple of months, or longer?)