Animation is not a new concept within our Libgdx set of cookbooks. Chapter 2, Working with 2D Graphics, guides you on how to manage sprite sheet-based animations, which is definitely the most common choice in general terms. However, it is not the only alternative, since there is commercial software that takes us through a more streamlined animation process, covering topics that range from the creation of animations to using them within your games.

This is the case of Spine, a popular skeletal animation editor created using Libgdx and offers runtimes for most of the programming languages in the market, adapting a lot of their variants to specific game engines/frameworks, where Libgdx is included too.

In Spine, you can create a hierarchy of bones you can animate using key frames and create interpolations between them. Textures can be attached to bones, resulting in smoothly animated characters. Spine also has a free license but doesn't allow exporting to .json...