Since I did not see the possibility of a Spine Animation plugin on the near horizon, I am experimenting with using the Spine-TS webgl runtime and integrating it with C3 through JS integration. I updated the Spine TS demo to load the Spine atlas and skeleton files from the local C3 project files. The runtime renders to a separate non-visible canvas each frame and the result is loaded into a C3 sprite animation frame to be displayed. The api provides control over the animation, mixing, animations, changing skeletons, skins, etc.
I currently have some simple controls to change the skeleton, change render resolution (the render canvas resolution), play/pause the animation.
It works fairly well, except for an occasional stutter (which seems to be the C3 execution stuttering due to movement of data into the spirte animation frame, in other threads and bug reports, I'm exploring that.)
Please feel free to test/extend/use/improve the project, please repost if you find some good improvements or extend it (or fix the stutter issue!)
Update 08/14/2019:
Updated the ElementQuad helper with the help of Ashley to use newly documented SDKs and released.
The Spine example is doing one Spine animation rendered to one separate canvas and the canvas is used for multiple ElementQuad instances (a light port of the Spine meshes demo.) For more Spine animations, this example may need another canvas per Spine animation and either a clone of ElementQuad or a new instance. Control of the animation will need to be done through JS calls to the Spine-TS API, movement, angle, size, effects, etc. on the resulting ElementQuad can be through C3 events.
ElementQuad Addon and Spine Example
Update 08/11/2019:
Created a plugin helper ElementQuad, which can use a canvas directly as a texture, which lowers memory usage and improves performance. There is now no stutter, one caveat is that it works best if the ElementQuad image size is the same as the Spine render canvas.
Older project with new ElementQuad plugin bundled in.
SpineJSEQTemplate.c3p
SpineAnimationTool
Older files
OutlineEffect
SpineJSTemplate.c3p