com.ga.3rd.spine/CHANGELOG.md

spine-unity-3.8.0-2021-03-19

# 3.8

## AS3
* **Breaking changes**
  * Renamed `Slot#getAttachmentVertices()` to `Slot#getDeform()`.
  * Changed the `.json` curve format and added more assumptions for omitted values, reducing the average size of JSON exports.
  * Renamed `Skin#addAttachment()` to `Skin#setAttachment()`.
  * Removed `VertexAttachment#applyDeform()` and replaced it with `VertexAttachment#deformAttachment`. The attachment set on this field is used to decide if a `DeformTimeline` should be applied to the attachment active on the slot to which the timeline is applied.
  * Removed `inheritDeform` field, getter, and setter from `MeshAttachment`.
  * Changed `.skel` binary format, added a string table. References to strings in the data resolve to this string table, reducing storage size of binary files considerably.
  * Changed the `.json` and `.skel` file formats to accomodate the new feature and file size optimiations. Old projects must be exported with Spine 3.8.20+ to be compatible with the 3.8 Spine runtimes.
  * Switched projects from FDT to Visual Studio Code. See updated `README.md` files for instructions.

* **Additions**
  * Added `SkeletonBinary` to load binary `.skel` files. See `MixAndMatchExample.as` in `spine-startling-example`.
  * Added `x` and `y` coordinates for setup pose AABB in `SkeletonData`.
  * Added support for rotated mesh region UVs.
  * Added skin-specific bones and constraints which are only updated if the skeleton's current skin contains them.
  * Improved Skin API to make it easier to handle mix-and-match use cases.
    * Added `Skin#getAttachments()`. Returns all attachments in the skin.
    * Added `Skin#getAttachments(int slotIndex)`. Returns all attachements in the skin for the given slot index.
    * Added `Skin#addSkin(Skin skin)`. Adds all attachments, bones, and skins from the specified skin to this skin.
    * Added `Skin#copySkin(Skin skin)`. Adds all attachments, bones, and skins from the specified skin to this skin. `VertexAttachment` are shallowly copied and will retain any parent mesh relationship. All other attachment types are deep copied.
  * Added `Attachment#copy()` to all attachment type implementations. This lets you deep copy an attachment to modify it independently from the original, i.e. when programmatically changing texture coordinates or mesh vertices.
  * Added `MeshAttachment#newLinkedMesh()`, creates a linked mesh linkted to either the original mesh, or the parent of the original mesh.
  * Added IK softness.

### Starling
* Added `MixAndMatchExample.as` to demonstrate the new Skin API additions and how to load binary `.skel` files.
* Switched projects from FDT to Visual Studio Code. See updated `README.md` files for instructions.

## C
* **Breaking changes**
  * Renamed `spSlot#attachmentVertices` to `spSlot#deform`.
  * Changed the `.json` curve format and added more assumptions for omitted values, reducing the average size of JSON exports.
  * Renamed `spSkin_addAttachment()` to `Skin#spSkin_addAttachment()`.
  * Removed `spVertexAttachment_applyDeform()` and replaced it with `VertexAttachment#deformAttachment`. The attachment set on this field is used to decide if a `spDeformTimeline` should be applied to the attachment active on the slot to which the timeline is applied.
  * Removed `inheritDeform` field, getter, and setter from `spMeshAttachment`.
  * Changed `.skel` binary format, added a string table. References to strings in the data resolve to this string table, reducing storage size of binary files considerably.
  * Changed the `.json` and `.skel` file formats to accomodate the new feature and file size optimiations. Old projects must be exported with Spine 3.8.20+ to be compatible with the 3.8 Spine runtimes.

* **Additions**
  * Added `x` and `y` coordinates for setup pose AABB in `spSkeletonData`.
  * Added support for rotated mesh region UVs.
  * Added skin-specific bones and constraints which are only updated if the skeleton's current skin contains them.
  * Improved Skin API to make it easier to handle mix-and-match use cases.
    * Added `spSkin_getAttachments()`. Returns all attachments in the skin.
    * Added `spSkin_getAttachments(int slotIndex)`. Returns all attachements in the skin for the given slot index.
    * Added `spSkin_addSkin(spSkin* skin)`. Adds all attachments, bones, and skins from the specified skin to this skin.
    * Added `spSkin_copySkin(spSkin* skin)`. Adds all attachments, bones, and skins from the specified skin to this skin. `spVertexAttachment` are shallowly copied and will retain any parent mesh relationship. All other attachment types are deep copied.
    * All attachments inserted into skins are reference counted. When the last skin referencing an attachment is disposed, the attachment will also be disposed.
  * Added `spAttachment_copy()` to all attachment type implementations. This lets you deep copy an attachment to modify it independently from the original, i.e. when programmatically changing texture coordinates or mesh vertices.
  * Added `spMeshAttachment_newLinkedMesh()`, creates a linked mesh linkted to either the original mesh, or the parent of the original mesh.
  * Added IK softness.

### Cocos2d-Objc
* Added mix-and-match example to demonstrate the new Skin API.
* Added `IKExample`.
* Added `SkeletonAnimation preUpdateWorldTransformsListener` and `SkeletonAnimation postUpdateWorldTransformsListener`. When set, these callbacks will be invokved before and after the skeleton's `updateWorldTransforms()` method is called. See the `IKExample` how it can be used.

### SFML
* Added mix-and-match example to demonstrate the new Skin API.
* Added `IKExample`.

## C++
* **Breaking Changes**
  * Renamed `Slot::getAttachmentVertices()` to `Slot::getDeform()`.
  * Changed the `.json` curve format and added more assumptions for omitted values, reducing the average size of JSON exports.
  * Renamed `Skin::addAttachment()` to `Skin::setAttachment()`.
  * Removed `VertexAttachment::applyDeform()` and replaced it with `VertexAttachment::getDeformAttachment()`. The attachment set on this field is used to decide if a `DeformTimeline` should be applied to the attachment active on the slot to which the timeline is applied.
  * Removed `_inheritDeform` field, getter, and setter from `MeshAttachment`.
  * Changed `.skel` binary format, added a string table. References to strings in the data resolve to this string table, reducing storage size of binary files considerably.
  * Changed the `.json` and `.skel` file formats to accomodate the new feature and file size optimiations. Old projects must be exported with Spine 3.8.20+ to be compatible with the 3.8 Spine runtimes.

* **Additions**
  * `AnimationState` and `TrackEntry` now also accept a subclass of `AnimationStateListenerObject` as a listener for animation events in the overloaded `setListener()` method.
  * `SkeletonBinary` and `SkeletonJson` now parse and set all non-essential data like audio path.
  * Added `x` and `y` coordinates for setup pose AABB in `SkeletonData`.
  * Added support for rotated mesh region UVs.
  * Added skin-specific bones and constraints which are only updated if the skeleton's current skin contains them.
  * Improved Skin API to make it easier to handle mix-and-match use cases.
    * Added `Skin#getAttachments()`. Returns all attachments in the skin.
    * Added `Skin#getAttachments(int slotIndex)`. Returns all attachements in the skin for the given slot index.
    * Added `Skin#addSkin(Skin &skin)`. Adds all attachments, bones, and skins from the specified skin to this skin.
    * Added `Skin#copySkin(Skin &skin)`. Adds all attachments, bones, and skins from the specified skin to this skin. `VertexAttachment` are shallowly copied and will retain any parent mesh relationship. All other attachment types are deep copied.
    * All attachments inserted into skins are reference counted. When the last skin referencing an attachment is disposed, the attachment will also be disposed.
  * Added `Attachment#copy()` to all attachment type implementations. This lets you deep copy an attachment to modify it independently from the original, i.e. when programmatically changing texture coordinates or mesh vertices.
  * Added `MeshAttachment#newLinkedMesh()`, creates a linked mesh linkted to either the original mesh, or the parent of the original mesh.
  * Added IK softness.
  * Exposed `x` and `y` on `SkeletonData` through getters and setters.

### Cocos2d-x
* Updated to cocos2d-x 3.17.1
* Added mix-and-match example to demonstrate the new Skin API.
* Exmaple project requires Visual Studio 2019 on Windows
* Added `IKExample`.
* Added `SkeletonAnimation::setPreUpdateWorldTransformsListener()` and `SkeletonAnimation::setPreUpdateWorldTransformsListener()`. When set, these callbacks will be invokved before and after the skeleton's `updateWorldTransforms()` method is called. See the `IKExample` how it can be used.

### SFML
* Added mix-and-match example to demonstrate the new Skin API.

### UE4
* Added `bAutoPlaying` flag to `USpineSkeletonAnimationComponent`. When `false`, the component will not update the internal animation state and skeleton.
* Updated example project to UE 4.22.
* (Re-)Importing Spine assets will perform a version compatibility check and alert users about mismatches in editor mode.
* `USpineSkeletonRendererComponent` allows passing a `USpineSkeletonComponent` to update it. This way, the renderer component can be used without a skeleton component on the same actor.
* Added blueprint-callable methods to `SpineSkeletonComponent` and `SpineSkeletonAnimationComponent` to query and set skins, and enumerate bones, slots, and animations.
* Extended skeleton data editor preview. The preview now shows bones, slots, animations, and skins found in the skeleton data. See this [blog post](http://esotericsoftware.com/blog/Unreal-Engine-4-quality-of-life-improvements).
* Added preview animation and skin fields, allowing you to preview animations and skins right in the editor. See this [blog post](http://esotericsoftware.com/blog/Unreal-Engine-4-quality-of-life-improvements).
* Removed dependency on `RHI`, `RenderCore`, and `ShaderCore`.
* Re-importing atlases and their textures now works consistently in all situations.
* Added mix-and-match example to demonstrate the new Skin API.
* Materials on `SkeletonRendererComponent` are now blueprint read and writeable. This allows setting dynamic material instances at runtime.
* Added `InitialSkin` property to `USpineWidget`. This allows previewing different skins in the UMG Designer. Initial skins can still be overridden via blueprint events such as `On Initialized`.

## C# ##
* **Breaking changes**
  * **Changed `IkConstraintData.Bones` type from `List<BoneData>` to `ExposedList<BoneData>`** for unification reasons. *Note: this modification will most likely not affect user code.*
  * Renamed `Slot.AttachmentVertices` to `Slot.Deform`.
  * Changed the `.json` curve format and added more assumptions for omitted values, reducing the average size of JSON exports.
  * Renamed `Skin.AddAttachment()` to `Skin.SetAttachment()`.
  * Removed `FindAttachmentsForSlot(int slotIndex, List<Attachment> attachments)` and `FindNamesForSlot (int slotIndex, List<string> names)` and replaced it with `Skin.GetAttachments(int slotIndex, List<SkinEntry> attachments)` which returns the combined `SkinEntry` object holding both name and attachment.
  * Removed `VertexAttachment.ApplyDeform()` and replaced it with `VertexAttachment.DeformAttachment`. The attachment set on this field is used to decide if a `DeformTimeline` should be applied to the attachment active on the slot to which the timeline is applied.
  * Removed `inheritDeform` field, getter, and setter from `MeshAttachment`.
  * Changed `.skel` binary format, added a string table. References to strings in the data resolve to this string table, reducing storage size of binary files considerably.
  * Changed the `.json` and `.skel` file formats to accomodate the new feature and file size optimiations. Old projects must be exported with Spine 3.8.20+ to be compatible with the 3.8 Spine runtimes.

* **Additions**
  * Added `x` and `y` coordinates for setup pose AABB in `SkeletonData`.
  * Added support for rotated mesh region UVs.
  * Added skin-specific bones and constraints which are only updated if the skeleton's current skin contains them.
  * Improved Skin API to make it easier to handle mix-and-match use cases.
    * Added `Skin.GetAttachments()`. Returns all attachments in the skin.
    * Added `Skin.GetAttachments(int slotIndex, List<SkinEntry> attachments)`. Returns all attachements in the skin for the given slot index. This method replaces `FindAttachmentsForSlot` and `FindNamesForSlot`.
    * Added `Skin.AddSkin(Skin skin)`. Adds all attachments, bones, and skins from the specified skin to this skin.
    * Added `Skin.CopySkin(Skin skin)`. Adds all attachments, bones, and skins from the specified skin to this skin. `VertexAttachment` are shallowly copied and will retain any parent mesh relationship. All other attachment types are deep copied.
  * Added `Attachment.Copy()` to all attachment type implementations. This lets you deep copy an attachment to modify it independently from the original, i.e. when programmatically changing texture coordinates or mesh vertices.
  * Added `MeshAttachment.NewLinkedMesh()`, creates a linked mesh linkted to either the original mesh, or the parent of the original mesh.
  * Added IK softness.

### Unity

* **Breaking changes**
  * **Officially supported Unity versions are 2017.1-2020.2**.
  * **Spine `.asmdef` files are again active by default**. They have previously been deactivated to `.txt` extension which is now no longer necessary.
  * **Removed PoseSkeleton() and PoseWithAnimation()** extension methods to prevent issues where animations are not mixed out. Problem was that these methods did not set AnimationState, leaving incorrect state at e.g. attachments enabled at slots when starting subsequent animations. As a replacement you can use `AnimationState.ClearTrack(0);` followed by `var entry = AnimationState.SetAnimation(0, animation, loop); entry.TrackTime = time` to achieve similar behaviour.
  * **The `Shadow alpha cutoff` shader parameter is now respecting slot-color alpha** values at all Spine shaders. A fragment's texture color alpha is multiplied with slot-color alpha before the result is tested against the `Shadow alpha cutoff` threshold.
  * **Removed redundant `Attachment.GetClone()` and `MeshAttachment.GetLinkedClone()` extension methods**. Use methods `Attachment.Copy` and `MeshAttachment.NewLinkedMesh()` instead.
  * **Renamed extension method `Attachment.GetClone(bool cloneMeshesAsLinked)` to `Attachment.GetCopy(bool cloneMeshesAsLinked)`** to follow the naming scheme of the Spine API.
  * `SkeletonDataAsset.atlasAssets` is now an array of the base class `AtlasAssetBase` instead of `SpineAtlasAsset`, which provides `IEnumerable<> Materials` instead of `List<> materials`. Replace any access via `atlasAsset.materials[0]` with `atlasAsset.Materials.First()` and add a `using System.Linq;` statement.
  * **Changed `MeshAttachment.GetLinkedMesh()` method signatures:** removed optional parameters `bool inheritDeform = true, bool copyOriginalProperties = false`.
  * Changed namespace `Spine.Unity.Modules` to `Spine.Unity` and `Spine.Unity.Examples` after restructuring (see section below) in respective classes:
    * When receiving namespace related errors, replace using statements of `using Spine.Unity.Modules.AttachmentTools;` with `using Spine.Unity.AttachmentTools;`. You can remove `using Spine.Unity.Modules;` statements when a `using Spine.Unity` statement is already present in the file.
    * `AttachmentTools`, `SkeletonPartsRenderer`, `SkeletonRenderSeparator`, `SkeletonRendererCustomMaterials` changed to namespace `Spine.Unity`.
    * `SkeletonGhost`, `SkeletonGhostRenderer`, `AtlasRegionAttacher`, `SkeletonGraphicMirror`, `SkeletonRagdoll`, `SkeletonRagdoll2D`, `SkeletonUtilityEyeConstraint`, `SkeletonUtilityGroundConstraint`, `SkeletonUtilityKinematicShadow` changed to namespace `Spine.Unity.Examples`.
  * Split `Editor/Utility/SpineEditorUtilities` class into multiple files with partial class qualifier.
    * Nested classes `SpineEditorUtilities.AssetUtility` and `SpineEditorUtilities.EditorInstantiation` are now no longer nested. If you receive namespace related errors, replace any occurrance of
      * `SpineEditorUtilities.AssetUtility` with `AssetUtility` and
      * `SpineEditorUtilities.EditorInstantiation` with `EditorInstantiation`.
  * **Timeline Support has been moved to a separate UPM Package** Previously the Spine Timeline integration was located in the `Modules/Timeline` directory and was deactivated by default, making it necessary to activate it via the Spine Preferences. Now the Timeline integration has been moved to an additional UPM package which can be found under `Modules/com.esotericsoftware.spine.timeline`.
   * **Installation:** You can download the Unity Package Manager (UPM) package via the [download page](http://esotericsoftware.com/spine-unity-download) or find it in the [spine-runtimes/spine-unity/Modules](https://github.com/EsotericSoftware/spine-runtimes/tree/3.8-beta/spine-unity/Modules) subdirectory on the git repository. You can then either unzip (copy if using git) the package to
      a) the `Packages` directory in your project where it will automatically be loaded, or
      b) to an arbitrary directory outside the Assets directory and then open Package Manager in Unity, select the `+` icon, choose `Add package from disk..` and point it to the package.json file.
      The Project panel should now show an entry `Spine Timeline Extensions` under `Packages`. If the directory is not yet listed, you will need to close and re-open Unity to have it display the directory and its contents.
  * `SkeletonMecanim`'s `Layer Mix Mode` enum name `MixMode.SpineStyle` has been renamed to `MixMode.Hard`. This is most likely not set via code and thus unlikely to be a problem. Serialized scenes and prefabs are unaffected.

* **Additions**
  * **Spine Preferences stored in Assets/Editor/SpineSettings.asset** Now Spine uses the new `SettingsProvider` API, storing settings in a SpineSettings.asset file which can be shared with team members. Your old preferences are automatically migrated to the new system.
  * Added support for Unity's SpriteMask to `SkeletonAnimation` and `SkeletonMecanim`. All mask interaction modes are supported. See this [blog post](http://esotericsoftware.com/blog/Unity-SpriteMask-and-RectMask2D-support).
  * Added support for Unity's RectMask2D to SkeletonGraphics. See this [blog post](http://esotericsoftware.com/blog/Unity-SpriteMask-and-RectMask2D-support).
  * Added `Create 2D Hinge Chain` button at `SkeletonUtilityBone` inspector, previously only `Create 3D Hinge Chain` was available.
  * **Now supporting Lightweight Render Pipeline (LWRP) through an additional UPM package.**
    * **Installation:** You can download the Unity Package Manager (UPM) package via the [download page](http://esotericsoftware.com/spine-unity-download) or find it in the [spine-runtimes/spine-unity/Modules](https://github.com/EsotericSoftware/spine-runtimes/tree/3.8-beta/spine-unity/Modules) subdirectory on the git repository. You can then either unzip (copy if using git) the package to
      * a) the `Packages` directory in your project where it will automatically be loaded, or
      * b) to an arbitrary directory outside the Assets directory and then open Package Manager in Unity, select the `+` icon, choose `Add package from disk..` and point it to the package.json file.

      > If you are using git and Unity 2019.2 or newer versions and receive an error that dependencies could not be resolved by the package manager (only higher versions of Unity's `Lightweight RP` package are available, e.g. `6.9.0` and up), please copy the prepared package-UNITYVERSION.json file for your Unity version (e.g. `package-2019.2.json`) over the existing package.json file to change the dependency accordingly. Unfortunately Unity's Package Manager does not provide a way to specify a version range for a dependency like "5.7.2 - 6.9.0" yet, so this manual step is necessary for git users.

      The Project panel should now show an entry `Spine Lightweight RP Shaders` under `Packages`. If the directory is not yet listed, you will need to close and re-open Unity to have it display the directory and its contents.
    * **Usage:** The package provides two shaders specifically built for the lightweight render pipeline:
      * `Lightweight Render Pipeline/Spine/Skeleton`, as a lightweight variant of the `Spine/Skeleton` shader,
      * `Lightweight Render Pipeline/Spine/Skeleton Lit`, as a lightweight variant of the `Spine/Skeleton Lit` shader and
      * `Lightweight Render Pipeline/Spine/Sprite`, as a lightweight variant of the `Spine/Sprite/Vertex Lit` and `Pixel Lit` shaders, which were not functioning in the lightweight render pipeline. The shaders can be assigned to materials as usual and will respect your settings of the assigned `LightweightRenderPipelineAsset` under `Project Settings - Graphics`.
    * **Restrictions** As all Spine shaders, the LWRP shaders **do not support `Premultiply alpha` (PMA) atlas textures in Linear color space**. Please export your atlas textures as `straight alpha` textures with disabled `Premultiply alpha` setting when using Linear color space. You can check the current color space via `Project Settings - Player - Other Settings - Color Space.`.
    * **Example:** You can find an example scene in the package under `com.esotericsoftware.spine.lwrp-shaders-3.8/Examples/LWRP Shaders.unity` that demonstrates usage of the LWRP shaders.
  * Added `Spine/Skeleton Lit ZWrite` shader. This variant of the `Spine/Skeleton Lit` shader writes to the depth buffer with configurable depth alpha threshold. Apart from that it is identical to `Spine/Skeleton Lit`.
  * Additional yield instructions to wait for animation track events `End`, `Complete` and `Interrupt`.
    * `WaitForSpineAnimationComplete` now proves an additional `bool includeEndEvent` parameter, defaults to `false` (previous behaviour).
    * Added a new `WaitForSpineAnimationEnd` yield instruction.
    * Added a new generic `WaitForSpineAnimation` yield instruction which can be configured to wait for any combination of animation track events. It is now used as base class for `WaitForSpineAnimationComplete` and `WaitForSpineAnimationEnd`.
  * Additional **Fix Draw Order** parameter at SkeletonRenderer, defaults to `disabled` (previous behaviour).
    Applies only when 3+ submeshes are used (2+ materials with alternating order, e.g. "A B A").
		If true, MaterialPropertyBlocks are assigned at each material to prevent aggressive batching of submeshes
		by e.g. the LWRP renderer, leading to incorrect draw order (e.g. "A1 B A2" changed to "A1A2 B").
		You can leave this parameter disabled when everything is drawn correctly to save the additional performance cost.
  * **Additional Timeline features.** SpineAnimationStateClip now provides a `Speed Multiplier`, a start time offset parameter `Clip In`, support for blending successive animations by overlapping tracks. An additional `Use Blend Duration` parameter *(defaults to true)* allows for automatic synchronisation of MixDuration with the current overlap blend duration. An additional Spine preferences parameter `Use Blend Duration` has been added which can be disabled to default to the previous behaviour before this update.
  * Additional `SpriteMask and RectMask2D` example scene added for demonstration of mask setup and interaction.
  * `Real physics hinge chains` for both 2D and 3D physics. The [SkeletonUtilityBone](http://esotericsoftware.com/spine-unity#SkeletonUtilityBone) Inspector provides an interface to create 2D and 3D hinge chains. Previously created chains have only been respecting gravity, but not momentum of the skeleton or parent bones. The new physics rig created when pressing `Create 3D Hinge Chain` and `Create 2D Hinge Chain` creates a more complex setup that also works when flipping the skeleton. Note that the chain root node is no longer parented to bones of the skeleton. This is a requirement in Unity to have momentum applied properly - do not reparent the chain root to bones of your skeleton, or you will loose any momentum applied by the skeleton's movement.
  * `Outline rendering functionality for all shaders.` Every shader now provides an additional set of `Outline` parameters to enable custom outline rendering. When outline rendering is enabled via the `Material` inspector, it automatically switches the shader to the respective `Spine/Outline` shader variant. Outlines are generated by sampling neighbour pixels, so be sure to add enough transparent padding when exporting your atlas textures to fit the desired outline width. In order to enable outline rendering at a skeleton, it is recommended to first prepare an additional outline material copy and then switch the material of the target skeleton to this material. This prevents unnecessary additional runtime material copies and drawcalls. Material switching can be prepared via a [SkeletonRendererCustomMaterials](http://esotericsoftware.com/spine-unity#SkeletonRendererCustomMaterials) component and then enabled or disabled at runtime. Alternatively, you can also directly modify the `SkeletonRenderer.CustomMaterialOverride` property.
  Outline rendering is fully supported on `SkeletonGraphic` shaders as well.
  * Added `SkeletonRenderer.EditorSkipSkinSync` scripting API property to be able to set custom skins in editor scripts. Enable this property when overwriting the Skeleton's skin from an editor script. Without setting this parameter, changes will be overwritten by the next inspector update. Only affects Inspector synchronisation of skin with `initialSkinName`, not startup initialization.
  * All `Spine/SkeletonGraphic` shaders now provide a parameter `CanvasGroup Compatible` which can be enabled to support `CanvasGroup` alpha blending. For correct results, you should then disable `Pma Vertex Colors` in the `SkeletonGraphic` Inspector, in section `Advanced` (otherwise Slot alpha will be applied twice).
  * **Now supporting Universal Render Pipeline (URP), including the 2D Renderer pipeline, through an additional UPM package.**
    * **Installation:** You can download the Unity Package Manager (UPM) package via the [download page](http://esotericsoftware.com/spine-unity-download) or find it in the [spine-runtimes/spine-unity/Modules](https://github.com/EsotericSoftware/spine-runtimes/tree/3.8-beta/spine-unity/Modules) subdirectory on the git repository. You can then either unzip (copy if using git) the package to
      * a) the `Packages` directory in your project where it will automatically be loaded, or
      * b) to an arbitrary directory outside the Assets directory and then open Package Manager in Unity, select the `+` icon, choose `Add package from disk..` and point it to the package.json file.

      The Project panel should now show an entry `Spine Universal RP Shaders` under `Packages`. If the directory is not yet listed, you will need to close and re-open Unity to have it display the directory and its contents.
    * **Usage:** The package provides two shaders specifically built for the universal render pipeline:
      * `Universal Render Pipeline/Spine/Skeleton`, as a universal variant of the `Spine/Skeleton` shader,
      * `Universal Render Pipeline/Spine/Skeleton Lit`, as a universal variant of the `Spine/Skeleton Lit` shader,
      * `Universal Render Pipeline/Spine/Sprite`, as a universal variant of the `Spine/Sprite/Vertex Lit` and `Pixel Lit` shaders, which were not functioning in the universal render pipeline,
	  * `Universal Render Pipeline/2D/Spine/Skeleton Lit`, as a universal 2D Renderer variant of the `Spine/Skeleton Lit` shader, and
      * `Universal Render Pipeline/2D/Spine/Sprite`, as a universal 2D Renderer variant of the `Spine/Sprite/Vertex Lit` and `Pixel Lit` shaders.
	  The shaders can be assigned to materials as usual and will respect your settings of the assigned `UniversalRenderPipelineAsset` under `Project Settings - Graphics`.
    * **Restrictions** As all Spine shaders, the URP shaders **do not support `Premultiply alpha` (PMA) atlas textures in Linear color space**. Please export your atlas textures as `straight alpha` textures with disabled `Premultiply alpha` setting when using Linear color space. You can check the current color space via `Project Settings - Player - Other Settings - Color Space.`.
    * **Example:** You can find an example scene in the package under `com.esotericsoftware.spine.urp-shaders-3.8/Examples/URP Shaders.unity` that demonstrates usage of the URP shaders.
  * Spine Preferences now provide an **`Atlas Texture Settings`** parameter for applying customizable texture import settings at all newly imported Spine atlas textures.
    When exporting atlas textures from Spine with `Premultiply alpha` enabled (the default), you can leave it at `PMATexturePreset`. If you have disabled `Premultiply alpha`, set it to the included `StraightAlphaTexturePreset` asset. You can also create your own `TextureImporter` `Preset` asset and assign it here (include `PMA` or `Straight` in the name). In Unity versions before 2018.3 you can use `Texture2D` template assets instead of the newer `Preset` assets. Materials created for imported textures will also have the `Straight Alpha Texture` parameter configured accordingly.
  * All `Sprite` shaders (including URP and LWRP extension packages) now provide an additional `Fixed Normal Space` option `World-Space`. PReviously options were limited to `View-Space` and `Model-Space`.
  * `SkeletonGraphic` now fully supports [`SkeletonUtility`](http://esotericsoftware.com/spine-unity#SkeletonUtility) for generating a hierarchy of [`SkeletonUtilityBones`](http://esotericsoftware.com/spine-unity#SkeletonUtilityBone) in both modes `Follow` and `Override`. This also enables creating hinge chain physics rigs and using `SkeletonUtilityConstraints` such as `SkeletonUtilityGroundConstraint` and `SkeletonUtilityEyeConstraint` on `SkeletonGraphic`.
  * Added `OnMeshAndMaterialsUpdated` callback event to `SkeletonRenderer` and `SkeletonGraphic`. It is issued at the end of `LateUpdate`, before rendering.
  * Added `Skeleton-OutlineOnly` single pass shader to LWRP and URP extension modules. It can be assigned to materials as `Universal Render Pipeline/Spine/Outline/Skeleton-OutlineOnly`. This allows for separate outline child *GameObjects* that reference the existing Mesh of their parent, and re-draw the mesh using this outline shader.
  * Added example component `RenderExistingMesh` to render a mesh again with different materials, as required by the new `Skeleton-OutlineOnly` shaders.
  In URP the outline has to be rendered via a separate GameObject as URP does not allow multiple render passes. To add an outline to your SkeletenRenderer:
    1) Add a child GameObject and move it a bit back (e.g. position Z = 0.01).
    2) Add a `RenderExistingMesh` component, provided in the `Spine Examples/Scripts/Sample Components` directory.
    3) Copy the original material, add *_Outline* to its name and set the shader to `Universal Render Pipeline/Spine/Outline/Skeleton-OutlineOnly`.
    4) Assign this *_Outline* material at the `RenderExistingMesh` component under *Replacement Materials*.
  * Added `Outline Shaders URP` example scene to URP extension module to demonstrate the above additions.
  * Added support for Unity's [`SpriteAtlas`](https://docs.unity3d.com/Manual/class-SpriteAtlas.html) as atlas provider (as an alternative to `.atlas.txt` and `.png` files) alongside a skeleton data file. There is now an additional `Spine SpriteAtlas Import` tool window accessible via `Window - Spine - SpriteAtlas Import`. Additional information can be found in a new section on the [spine-unity documentation page](http://esotericsoftware.com/spine-unity#Advanced---Using-Unity-SpriteAtlas-as-Atlas-Provider).
  * Added support for **multiple atlas textures at `SkeletonGraphic`**. You can enable this feature by enabling the parameter `Multiple CanvasRenders` in the `Advanced` section of the `SkeletonGraphic` Inspector. This automatically creates the required number of child `CanvasRenderer` GameObjects for each required draw call (submesh).
  * Added support for **Render Separator Slots** at `SkeletonGraphic`. Render separation can be enabled directly in the `Advanced` section of the `SkeletonGraphic` Inspector, it does not require any additional components (like `SkeletonRenderSeparator` or `SkeletonPartsRenderer` for `SkeletonRenderer` components). When enabled, additional separator GameObjects will be created automatically for each separation part, and `CanvasRenderer` GameObjects re-parented to them accordingly. The separator GameObjects can be moved around and re-parented in the hierarchy according to your requirements to achieve the desired draw order within your `Canvas`. A usage example can be found in the updated `Spine Examples/Other Examples/SkeletonRenderSeparator` scene.
  * Added `SkeletonGraphicCustomMaterials` component, providing functionality to override materials and textures of a `SkeletonGraphic`, similar to `SkeletonRendererCustomMaterials`. Note: overriding materials or textures per slot is not provided due to structural limitations.
  * Added **Root Motion support** for `SkeletonAnimation`, `SkeletonMecanim` and `SkeletonGraphic` via new components `SkeletonRootMotion` and `SkeletonMecanimRootMotion`. The `SkeletonAnimation` and `SkeletonGraphic` component Inspector now provides a line `Root Motion` with `Add Component` and `Remove Component` buttons to add/remove the new `SkeletonRootMotion` component to your GameObject. The `SkeletonMecanim` Inspector detects whether root motion is enabled at the `Animator` component and adds a `SkeletonMecanimRootMotion` component automatically.
  * `SkeletonMecanim` now provides an additional `Custom MixMode` parameter under `Mecanim Translator`. It is enabled by default in version 3.8 to maintain current behaviour, using the set `Mix Mode` for each Mecanim layer. When disabled, `SkeletonMecanim` will use the recommended `MixMode` according to the layer blend mode. Additional information can be found in the [Mecanim Translator section](http://esotericsoftware.com/spine-unity#Parameters-for-animation-blending-control) on the spine-unity documentation pages.
  * Added **SkeletonGraphic Timeline support**. Added supprot for multi-track Timeline preview in the Editor outside of play mode (multi-track scrubbing). See the [Timeline-Extension-UPM-Package](http://esotericsoftware.com/spine-unity#Timeline-Extension-UPM-Package) section of the spine-unity documentation for more information.
  * Added support for double-sided lighting at all `SkeletonLit` shaders (including URP and LWRP packages).
  * Added frustum culling update mode parameters `Update When Invisible` (Inspector parameter) and `UpdateMode` (available via code) to all Skeleton components. This provides a simple way to disable certain updates when the `Renderer` is no longer visible (outside all cameras, culled in frustum culling). The new `UpdateMode` property allows disabling updates at a finer granularity level than disabling the whole component. Available modes are: `Nothing`, `OnlyAnimationStatus`, `EverythingExceptMesh` and `FullUpdate`.
  * Added a new `Spine/Outline/OutlineOnly-ZWrite` shader to provide correct outline-only rendering. Note: the shader requires two render passes and is therefore not compatible with URP. The `Spine Examples/Other Examples/Outline Shaders` example scene has been updated to demonstrate the new shader.
  * Added `OnMeshAndMaterialsUpdated` callback event to `SkeletonRenderSeparator` and `SkeletonPartsRenderer`. It is issued at the end of `LateUpdate`, before rendering.
  * Added `Root Motion Scale X/Y` parameters to `SkeletonRootMotionBase` subclasses (`SkeletonRootMotion` and `SkeletonMecanimRootMotion`). Also providing `AdjustRootMotionToDistance()` and other methods to allow for easy delta compensation. Delta compensation can be used to e.g. stretch a jump to a given distance. Root motion can be adjusted at the start of an animation or every frame via `skeletonRootMotion.AdjustRootMotionToDistance(targetPosition - transform.position, trackIndex);`.
  * Now providing a `Canvas Group Tint Black` parameter at the `SkeletonGraphic` Inspector in the `Advanced` section. When using the `Spine/SkeletonGraphic Tint Black` shader you can enable this parameter to receive proper blending results when using `Additive` blend mode under a `CanvasGroup`. Be sure to also have the parameter `CanvasGroup Compatible` enabled at the shader. Note that the normal `Spine/SkeletonGraphic` does not support `Additive` blend mode at a `CanvasGroup`, as it requires additional shader channels to work.
  * Added `Mix and Match Skins` example scene to demonstrate how the 3.8 Skin API and combining skins can be used for a wardrobe and equipment use case.
  * Spine Timeline Extensions: Added `Hold Previous` parameter at `SpineAnimationStateClip`.
  * Added more warning messages at incompatible SkeletonRenderer/SkeletonGraphic Component vs Material settings. They appear both as an info box in the Inspector as well as upon initialization in the Console log window. The Inspector box warnings can be disabled via `Edit - Preferences - Spine`.
  * Now providing `BeforeApply` update callbacks at all skeleton animation components (`SkeletonAnimation`, `SkeletonMecanim` and `SkeletonGraphic`).
  * Added `BoundingBoxFollowerGraphic` component. This class is a counterpart of `BoundingBoxFollower` that can be used with `SkeletonGraphic`.
  * Added Inspector context menu functions `SkeletonRenderer - Add all BoundingBoxFollower GameObjects` and `SkeletonGraphic - Add all BoundingBoxFollowerGraphic GameObjects` that automatically generate bounding box follower GameObjects for every `BoundingBoxAttachment` for all skins of a skeleton.
  * `GetRemappedClone()` now provides an additional parameter `pivotShiftsMeshUVCoords` for `MeshAttachment` to prevent uv shifts at a non-central Sprite pivot. This parameter defaults to `true` to maintain previous behaviour.
  * `SkeletonRenderer` components now provide an additional update mode `Only Event Timelines` at the `Update When Invisible` property. This mode saves additional timeline updates compared to update mode `Everything Except Mesh`.
  * Now all URP (Universal Render Pipeline) and LWRP (Lightweight Render Pipeline) shaders support SRP (Scriptable Render Pipeline) batching. See [Unity SRPBatcher documentation pages](https://docs.unity3d.com/Manual/SRPBatcher.html) for additional information.
  * Sprite shaders now provide four `Diffuse Ramp` modes as an Inspector Material parameter: `Hard`, `Soft`, `Old Hard` and `Old Soft`. In spine-unity 3.8 it defaults to `Old Hard` to keep the behaviour of existing projects unchanged. Note that `Old Hard` and `Old Soft` ramp versions were using only the right half of the ramp texture, and additionally multiplying the light intensity by 2, both leading to brighter lighting than without a ramp texture active. The new ramp modes `Hard` and `Soft` use the full ramp texture and do not modify light intensity, being consistent with lighting without a ramp texture active.
  * Added **native support for slot blend modes** `Additive`, `Multiply` and `Screen` with automatic assignment at newly imported skeleton assets. `BlendModeMaterialAssets` are now obsolete and replaced by the native properties at `SkeletonDataAsset`. The `SkeletonDataAsset` Inspector provides a new `Blend Modes - Upgrade` button to upgrade an obsolete `BlendModeMaterialAsset` to the native blend modes properties. This upgrade will be performed automatically on imported and re-imported assets in Unity 2020.1 and newer to prevent reported `BlendModeMaterialAsset` issues in these Unity versions. spine-unity 4.0 and newer will automatically perform this upgrade regardless of the Unity version.
  * `BoneFollower` and `BoneFollowerGraphic` components now provide better support for following bones when the skeleton's Transform is not the parent of the follower's Transform. Previously e.g. rotating a common parent Transform did not lead to the desired result, as well as negatively scaling a skeleton's Transform when it is not a parent of the follower's Transform.
  * URP and LWRP `Sprite` and `SkeletonLit` shaders no longer require `Advanced - Add Normals` enabled to properly cast and receive shadows. It is recommended to disable `Add Normals` if normals are otherwise not needed.

* **Changes of default values**
  * `SkeletonMecanim`'s `Layer Mix Mode` now defaults to `MixMode.MixNext` instead of `MixMode.MixAlways`.
  * `BlendModeMaterialAsset` and it's instance `Default BlendModeMaterials.asset` now have `Apply Additive Material` set to `true` by default in order to apply all blend modes by default.

* **Deprecated**
  * Deprecated `Modules/SlotBlendModes/SlotBlendModes` component. Changed namespace from `Spine.Unity.Modules` to `Spine.Unity.Deprecated`. Moved to `Deprecated/SlotBlendModes`.

* **Restructuring (Non-Breaking)**

  Note: The following changes will most likely not affect users of the Spine-Unity runtime as the API remains unchanged and no references are invalidated.
  * Removed duplicates of `.cginc` files in `Modules/Shaders/Sprite` that were also present in the `Modules/Shaders/Sprite/CGIncludes` directory.
  * Moved shaders from `Modules/Shaders` to `Shaders` directory.
  * Moved shaders from `Modules/SkeletonGraphic/Shaders` to `Shaders/SkeletonGraphic`.
  * Renamed shader `Shaders/Spine-SkeletonLit.shader` to `Shaders/Spine-Skeleton-Lit.shader`.
  * Moved components from `SkeletonGraphic` to `Components` and `Components/Following` except for `SkeletonGraphicMirror` which was moved to `Spine Examples/Scripts/Sample Components`.
  * Moved `BoneFollower`, `BoneFollowerGraphic` and `PointFollower` from `Components` directory to `Components/Following`.
  * Moved `BoundingBoxFollower` component from `Modules/BoundingBoxFollower` to `Components/Following`.
  * Moved `Modules/SkeletonRenderSeparator` directory to `Components/SkeletonRenderSeparator`.
  * Moved `Modules/CustomMaterials` directory to `Components/SkeletonRendererCustomMaterials`.
  * Moved `Asset Types/BlendModeMaterialsAsset.cs` class, `Shaders/BlendModes/Default BlendModeMaterials.asset` and materials from `Shaders/BlendModes` to `SkeletonDataModifierAssets/BlendModeMaterials` directory.
  * Moved `Modules/Ghost` directory to `Spine Examples/Scripts/Sample Components/Ghost`.
  * Moved `Modules/SkeletonUtility Modules` directory to `Spine Examples/Scripts/Sample Components/SkeletonUtility Modules`.
  * Moved `Modules/AnimationMatchModifier` directory to `Spine Examples/Scripts/MecanimAnimationMatchModifier`.
  * Moved `SkeletonRagdoll` and `SkeletonRagdoll2D` components from `Modules/Ragdoll` directory to `Spine Examples/Scripts/Sample Components/SkeletonUtility Modules`.
  * Moved `AttachmentTools.cs` to `Utility` directory.
  * Split the file `AttachmentTools` into 5 separate files for each contained class. No namespace or other API changes performed.
  * Split the file `Mesh Generation/SpineMesh` into 4 separate files for each contained class. No namespace or other API changes performed.
  * Moved `SkeletonExtensions.cs` to `Utility` directory.
  * Moved `Modules/YieldInstructions` directory to `Utility/YieldInstructions`.
  * Moved corresponding editor scripts of the above components to restructured directories as well.
  * Renamed inspector editor class `PointFollowerEditor` to `PointFollowerInspector` for consistency reasons.

### XNA/MonoGame
* Updated to latest MonoGame version 3.7.1
* Rewrote example project to be cleaner and better demonstrate basic Spine features.
* Added mix-and-match example to demonstrate the new Skin API.
* Added normalmap support via `SpineEffectNormalmap` and support for loading multiple texture layers following a suffix-pattern. Please see the example code on how to use them.

## Java
* **Breaking changes**
  * Renamed `Slot#getAttachmentVertices()` to `Slot#getDeform()`.
  * Changed the `.json` curve format and added more assumptions for omitted values, reducing the average size of JSON exports.
  * Renamed `Skin#addAttachment()` to `Skin#setAttachment()`.
  * Removed `VertexAttachment#applyDeform()` and replaced it with `VertexAttachment#deformAttachment`. The attachment set on this field is used to decide if a `DeformTimeline` should be applied to the attachment active on the slot to which the timeline is applied.
  * Removed `inheritDeform` field, getter, and setter from `MeshAttachment`.
  * Changed `.skel` binary format, added a string table. References to strings in the data resolve to this string table, reducing storage size of binary files considerably.
  * `JsonRollback` tool now converts from 3.8 JSON to 3.7.
  * Changed the `.json` and `.skel` file formats to accomodate the new feature and file size optimiations. Old projects must be exported with Spine 3.8.20+ to be compatible with the 3.8 Spine runtimes.

* **Additions**
  * Added `x` and `y` coordinates for setup pose AABB in `SkeletonData`.
  * Added support for rotated mesh region UVs.
  * Added skin-specific bones and constraints which are only updated if the skeleton's current skin contains them.
  * Improved Skin API to make it easier to handle mix-and-match use cases.
    * Added `Skin#getAttachments()`. Returns all attachments in the skin.
    * Added `Skin#getAttachments(int slotIndex)`. Returns all attachements in the skin for the given slot index.
    * Added `Skin#addSkin(Skin skin)`. Adds all attachments, bones, and skins from the specified skin to this skin.
    * Added `Skin#copySkin(Skin skin)`. Adds all attachments, bones, and skins from the specified skin to this skin. `VertexAttachment` are shallowly copied and will retain any parent mesh relationship. All other attachment types are deep copied.
  * Added `Attachment#copy()` to all attachment type implementations. This lets you deep copy an attachment to modify it independently from the original, i.e. when programmatically changing texture coordinates or mesh vertices.
  * Added `MeshAttachment#newLinkedMesh()`, creates a linked mesh linkted to either the original mesh, or the parent of the original mesh.
  * Added IK softness.

### libGDX
* `SkeletonViewer` can load a skeleton by specifying it as the first argument on the command line.
* Added mix-and-match example to demonstrate the new Skin API.

## Lua
* **Breaking changes**
  * Renamed `Slot:getAttachmentVertices()` to `Slot#deform`.
  * Changed the `.json` curve format and added more assumptions for omitted values, reducing the average size of JSON exports.
  * Renamed `Skin:addAttachment()` to `Skin#setAttachment()`.
  * Removed `VertexAttachment:applyDeform()` and replaced it with `VertexAttachment#deformAttachment`. The attachment set on this field is used to decide if a `DeformTimeline` should be applied to the attachment active on the slot to which the timeline is applied.
  * Removed `inheritDeform` field, getter, and setter from `MeshAttachment`.
  * Changed the `.json` file format to accomodate the new feature and file size optimiations. Old projects must be exported with Spine 3.8.20+ to be compatible with the 3.8 Spine runtimes.

* **Additions**
  * Added `x` and `y` coordinates for setup pose AABB in `SkeletonData`.
  * Added support for rotated mesh region UVs.
  * Added skin-specific bones and constraints which are only updated if the skeleton's current skin contains them.
  * Improved Skin API to make it easier to handle mix-and-match use cases.
    * Added `Skin:getAttachments()`. Returns all attachments in the skin.
    * Added `Skin:getAttachments(slotIndex)`. Returns all attachements in the skin for the given slot index.
    * Added `Skin:addSkin(Skin skin)`. Adds all attachments, bones, and skins from the specified skin to this skin.
    * Added `Skin:copySkin(Skin skin)`. Adds all attachments, bones, and skins from the specified skin to this skin. `VertexAttachment` are shallowly copied and will retain any parent mesh relationship. All other attachment types are deep copied.
  * Added `Attachment:copy()` to all attachment type implementations. This lets you deep copy an attachment to modify it independently from the original, i.e. when programmatically changing texture coordinates or mesh vertices.
  * Added `MeshAttachment:newLinkedMesh()`, creates a linked mesh linkted to either the original mesh, or the parent of the original mesh.
  * Added IK softness.

### Love2D
* Added support for 0-1 RGBA color component range change in Löve 0.11+. Older Löve versions using the 0-255 range are still supported!
* Added mix-and-match example to demonstrate the new Skin API.

### Corona
* Added mix-and-match example to demonstrate the new Skin API.

## Typescript/Javascript
* **Breaking changes**
  * Renamed `MixDirection.in/out` to `MixDirection.mixIn/mixOut` as it was crashing a JS compressor.
  *  Renamed `Slot#getAttachmentVertices()` to `Slot#getDeform()`.
  * Changed the `.json` curve format and added more assumptions for omitted values, reducing the average size of JSON exports.
  * Renamed `Skin#addAttach