I try this code, but can't attach (normal head1) and (snake head1) to (head1 skin).

head (slot)
head1 (skin attachment)
normal head1 (region attachment)
snake head1 (region attachment)

I tried like this, but failed. It seems a skin sttachment can get one region attachment.
What am I doing wrong?

great quick question region attachment i attack my CCSprite ,FYI im on Cocos2d .

Any future plan for that special attachment ?

I made a match skin - region attachment successfully like sample code due to your advice. But I can click visibility just one skin so I can't turn on both [one head] and [one wing] at the same time. If I turn on a head, I can't turn on any wing. To make a animation, I need to see them all visible. In this case, I think it need "multiple turn on" of several skins in spine tool. But perhaps it harms to original skin function. How do you think about this?

I like the idea. It requires a bit of thought to implement it so it's smooth to work with, but maybe it can be done.

Could you provide an example in ActionScript for this? I have tried to create a skin at runtime that tries to emulate more or less what you describe in your first post here. But the thing is when I try to use a skin I create at runtime the slots that are assigned attachments in that skin are shown as empty in the animation(s). If I switch to any of the other skins I have created at design time it works fine, but not with the runtime created one.

To me it seems that you cannot assign region attachments to skin attachments below a slot through the as3 spine framework. Only region attachmements directly to slots, and only if there are no skin attachments assign to that slot. Am I wrong in this assumption?

Note: this code is very simplified, but I wrote it as a proof of concept of a runtime created skin in actionscript. We are still trying to figure out if we are going to use skins or just region attachments with more overlapping slots or a mix of the two. I know that what this code does should not be done with a skin, but again this is just a simple proof of concept test.

The spine animation, for the section handled in the code below, has this structure:

hand2 (slot)
   weapon (skin attachment)
      v_arm_hand (region attachment)
      v_arm_hand_club (region attachment)
      v_arm_hand_sword (region attachment)
basic (skin)
   weapon -> v_arm_hand
weapon_upgrade_0 (skin)
   weapon -> v_arm_hand_club
weapon_upgrade_1 (skin)
   weapon -> v_arm_hand_sword

public class SpinePOC extends Sprite
{
   [Embed(source = "../assets/spine/hero04/LoC.xml", mimeType = "application/octet-stream")]
   static public const HeroAtlas:Class;
   

   [Embed(source = "../assets/spine/hero04/LoC.png")]
   static public const HeroAtlasTexture:Class;
   

   [Embed(source = "../assets/spine/hero04/skeleton.json", mimeType = "application/octet-stream")]
   static public const HeroJson:Class;
   

   private var atlasLoader:StarlingAtlasAttachmentLoader;
   private var skeleton:SkeletonAnimationSprite;
   

   public function SpinePOC()
   {
      var texture:Texture = Texture.fromBitmap(new HeroAtlasTexture());
      var xml:XML = XML(new HeroAtlas());
      var atlas:TextureAtlas = new TextureAtlas(texture, xml);
   

  atlasLoader = new StarlingAtlasAttachmentLoader(atlas);
  var json:SkeletonJson = new SkeletonJson(atlasLoader);
  var skeletonData:SkeletonData = json.readSkeletonData(new HeroJson());
   
  skeleton = new SkeletonAnimationSprite(skeletonData);
  skeleton.setAnimation("idle", true);
   
  // create a new skin
  var skin1:Skin = new Skin("test_skin");
  var idHand2:int = skeleton.skeleton.findSlotIndex("hand2");
  
  // The below two lines produce the same result: empty slot
  // "weapon" is the skin attachment name and "v_arm_hand_club" is the region attachment I try to attach to it
  //skin1.addAttachment(idHand2, "weapon", new Attachment("v_arm_hand_club"));
  skin1.addAttachment(idHand2, "weapon", atlasLoader.newAttachment(null, AttachmentType.region, "v_arm_hand_club"));
  skeletonData.addSkin(skin1);
  skeleton.skeleton.skin = skin1;
  skeleton.skeleton.setToSetupPose();
   
  addChild(skeleton);
  Starling.juggler.add(skeleton);
   }
}

If I do this:

skeleton.skeleton.skinName = "basic";

or

skeleton.skeleton.skinName = "weapon_upgrade_0";

then the animation has content in the hand2 slot. But my runtime created skin leaves the slot empty.

One thing I noticed is in the spin/Skin class there is this attachAll function. It has a for each loop that wants to loop through the properties of an object (oldSkin.attachments). If you loop through an object with a for each it will only return the objects property values (not the property keys). So if you change it to a normal for loop it does return the property keys instead and the rest of the code in there makes more sense But still after that change the slot.attachment is always null for the slots that have skin attachments. I don't know if this has anything to do with this, it is just an observation I made yesterday.

You're welcome

Well, I am calling setToSetupPose right after I set the skin to my runtime created one in the above example.

skeleton.skeleton.skin = skin1;
skeleton.skeleton.setToSetupPose();

The thing is even if I first set the skin to a designtime created skin and then try to set it to my runtime skin (even with doing setToSetupPose after each setting of skin) the loop inside Skin.attachAll never does anything because slot.attachment is always null for the slots that have a skin attachment. It's as if slot.attachment will only contain region attachments and not skin attachments. See my point?

But despite this it always works if I change between designtime created skins. It is only the runtime created skin I can't get to work.
Anyway, I am not at work now, so I'll look deeper into this tomorrow morning.

The thing is that we are using keyed skin attachments in the animations, so just assigning region attachments to those slots does not make sense. Besides there is a runtime error if I try to assign a region attachment programmatically to a slot that has a skin attachment assigned in the UI.

skeleton.skeleton.setAttachment("hand2", "v_arm_hand__sword");
skeleton.skeleton.setToSetupPose();

results in:

ArgumentError: Attachment not found: v_arm_hand__sword, for slot: hand2
	at spine::Skeleton/setAttachment()[C:\work\component\ngp\game_clients\slotmachines\qb2-DEV\legendsofcolosseum\src\spine\Skeleton.as:181]
	at objects::SpinePOC()[C:\work\component\ngp\game_clients\slotmachines\qb2-DEV\legendsofcolosseum\src\objects\SpinePOC.as:101]

The setup pose attachments in the JSON looks like this:

// the "weapon" attachment is a skin attachment
"slots": [
	...
	{ "name": "hand2", "bone": "v_arm_hand", "attachment": "weapon" }
],

But I do not get a runtime error if I do like this:

skeleton.skeleton.setAttachment("hand2", "weapon");
skeleton.skeleton.setToSetupPose();

If I do the above for a skin created in the UI, nothing special happens (it looks the same as if I would not have made that setAttachment call, but the slot has content at least). But what does that line of code actually do? It reassigns the same skin attachment to the slot, but how to tell what region attachment should be linked to that skin attachment?

If I first set the skin to a UI created skin, do setToSetupPose and then apply a a programmatically created skin and do setToSetupPose and do the above setAttchment it renders the slot empty during the animation.

Is my way of creating a skin programmatically incorrect?

var skin1:Skin = new Skin("test");
var idHand2:int = skeleton.skeleton.findSlotIndex("hand2");
skin1.addAttachment(idHand2, "weapon", atlasLoader.newAttachment(null, AttachmentType.region, "v_arm_hand_club"));
skeletonData.addSkin(skin1);
skeleton.skeleton.skin = skin1;
skeleton.skeleton.setToSetupPose();

this has the same result:

var skin1:Skin = new Skin("test");
var idHand2:int = skeleton.skeleton.findSlotIndex("hand2");
skin1.addAttachment(idHand2, "weapon", atlasLoader.newAttachment(null, AttachmentType.region, "v_arm_hand_club"));
skeletonData.addSkin(skin1);
skeleton.skeleton.skin = skin1;
skeleton.skeleton.setToSetupPose();
// And the below lines should not be needed anyway, as the setting of the skin should do it
skeleton.skeleton.setAttachment("hand2", "weapon");
skeleton.skeleton.setToSetupPose();

Or is it in fact impossible to programmatically create a skin that attach different region attachment to slots with skin attachment? Because if it is not currently possible we have to try to use more slots with only region attachments instead. And I want to sort this before the graphics artist start to do too much work if he then is forced to redo it another way.

The reason we want to do it like this is that we have a character that can have 5 different races and 2 different genders and each slot uses several different keyed attachments and most of the slots also will equip different kinds of gear. That is why we need to be able to control it by code as not to be forced to create thousands of animations

Some progress.

If I first activate a skin with the desired attachment and retrieve that attachment and store it in a variable and then create my new skin and use that variable instead of using the atlasLoader it works fine.

skeleton.skeleton.skinName = "basic";
skeleton.skeleton.setToSetupPose();
var idHand2:int = skeleton.skeleton.findSlotIndex("hand2");
var attachment:Attachment = skeleton.skeleton.getAttachmentForSlotIndex(idHand2, "weapon");
skin1.addAttachment(idHand2, "weapon", attachment);
skeletonData.addSkin(skin1);
skeleton.skeleton.skin = skin1;
skeleton.skeleton.setToSetupPose();

Is this how I have to go by? Would be nice if I could do this directly by using the atlasLoader so I don't have to activate a skin for each slot to pick all the attchments I want to use.