AnimationRootNode is a base class for AnimationNodes that hold a complete animation. A complete animation refers to the output of an AnimationNodeOutput in an AnimationNodeBlendTree or the output of another AnimationRootNode. Used for AnimationTree.tree_root or in other AnimationRootNodes.

Examples of built-in root nodes include AnimationNodeBlendTree (allows blending nodes between each other using various modes), AnimationNodeStateMachine (allows to configure blending and transitions between nodes using a state machine pattern), AnimationNodeBlendSpace2D (allows linear blending between three AnimationNodes), AnimationNodeBlendSpace1D (allows linear blending only between two AnimationNodes).