[x3d-public] Spine links (related to our current talk on web3d call)

[Michalis Kamburelis]

Spine is a software to design 2D skeletal animations. They can be
exported to a documented format called "Spine JSON".

CGE supports it, and internally converts "Spine JSON" to an X3D node
graph. Each animation results in an X3D TimeSensor node, which is
marked as EXPORTed, and thus can be easily accessed by it's name (like
"Walk", "Idle") and played (from the surrounding X3D scene, or CGE
"TCastleScene.PlayAnimation"). This is most probably the same approach
I'll use for glTF animations.

Main page of Spine creators:

  http://esotericsoftware.com/

(You can download for free, but the version that allows to export  to
"Spine JSON" format is paid.)

Spine JSON docs:
  http://esotericsoftware.com/spine-json-format

CGE docs:
  https://github.com/castle-engine/castle-engine/wiki/Spine

Also related is "Dragon Bones", which is free, and can export to a
format compatible with Spine JSON:

  http://dragonbones.com/en/index.html
  https://castle-engine.io/creating_data_dragon_bones.php

Regards,
Michalis