When comparing Spine vs Puppet2D, the Slant community recommends Spine for most people. In the question“What are the best 2D animation tools for Unity?” Spine is ranked 3rd while Puppet2D is ranked 6th. The most important reason people chose Spine is:
Ranked in these QuestionsQuestion Ranking
Pro Integration libraries support most engines
Pro Allows for easy use of artwork from third party programs
Spine's developers provide scripts which makes exporting artwork from third party programs much easier to do.
Pro Simplified UI allows for an easy learning curve
No-nonsense workflow allows you to create your artwork in programs much better suited for the task like Illustrator and Inkscape for example, while Spine itself focuses only on the important task of skeletal animation.
Pro Community-driven feature roadmap
Esoteric Software maintains public Waffle issue trackers to help plan and prioritize feature additions.
Pro Price high for this product
Pro Mesh Deformation
Instead of having to change sprites to bend legs or other joints mesh deformation changes the mesh shape based on joint weights to bend and move.
Pro Inverse Kinematic bones
Bones will move and rotate reacting to the position of the rest of the skeleton. The animator does not have to animate each part of a joint but rather have it follow realistically. Also can be used for ragdoll effects based on physics.
Pro Built on top of Unity’s animation system
Mecanim and state machines work natively since Puppet2D builds on top of Unity’s built in animation system.
Con Spine Professional is expensive
Spine Essential includes nearly all features, except IK, weights, and meshes. Spine Professional is expensive, though it does give all future updates for life (Spine is updated very often).
Con No integration for lesser known engines
Spine does not directly support some game engines, such as Construct 2 or Clickteam Fusion.
Con Forced editor scaling causes problems
Puppet2D adjust the scaling of bones in the editor for display purposes, which results in unintended behavior if other objects use a bone as a parent.