The spine-tk2d runtime provides functionality to load, manipulate and render Spine skeletal animation data using 2D Toolkit for Unity. spine-tk2d is based on spine-csharp and is very similar to spine-unity.

A Spine skeleton is a GameObject and can be used throughout Unity like any other GameObject. It depends only on Unity's MeshRenderer, so it is close to the metal. SkeletonUtility allows other GameObjects to interact with the Spine skeleton, to control bones in the skeleton, be controlled by the skeleton, attach colliders, etc.

spine-tk2d differs from spine-unity in that a TK2D atlas is used instead of a Spine atlas. Also, spine-unity has more tools for automatically importing Spine skeleton data and atlases, while spine-tk2d requires setting up the TK2D manually. spine-unity provides a GameObject that renders a Spine skeleton, so can be used with TK2D (or any other Unity plugin).

Documentation

The spine-tk2d video shows some differences between spine-tk2d and spine-unity. Except for setting up the texture atlas, everything in spine-tk2d works the same as spine-unity. The Spine Unity Examples forum thread has many videos on how to use both spine-unity and spine-tk2d features.

Quick installation

Download and run this Unity package:

spine-tk2d.unitypackage

In the Assets/examples folder you will find example scenes that demonstrate various spine-tk2d features. Also see the example scenes in spine-unity.

Manual installation

To open the spine-tk2d example scenes:

Download the Spine Runtimes source using git or by downloading it as a zip.
Copy the contents of spine-csharp/src to spine-tk2d/Assets/spine-csharp.
Open the spine-tk2d/Assets/examples/spineboy/spineboy.unity scene file using Unity 4.3.4+.
Import 2D Toolkit into the example project.

To use spine-tk2d in your own Unity project:

Copy the contents of spine-csharp/src to Assets/spine-csharp in your project.
Copy the spine-tk2d/Assets/spine-tk2d to Assets/spine-tk2d in your project.
Import 2D Toolkit into your project.

Notes

Atlas images should use premultiplied alpha when using the shaders that come with spine-tk2d.
This slightly outdated spine-tk2d setup video may still be useful for manual installation.