A node used for advanced animation transitions in an [AnimationPlayer]. A node used for advanced animation transitions in an [AnimationPlayer]. [b]Note:[/b] When linked with an [AnimationPlayer], several properties and methods of the corresponding [AnimationPlayer] will not function as expected. Playback and transitions should be handled using only the [AnimationTree] and its constituent [AnimationNode](s). The [AnimationPlayer] node should be used solely for adding, deleting, and editing animations. $DOCS_URL/tutorials/animation/animation_tree.html https://godotengine.org/asset-library/asset/678 The path to the [Node] used to evaluate the [AnimationNode] [Expression] if one is not explicitly specified internally. The path to the [AnimationPlayer] used for animating. The root animation node of this [AnimationTree]. See [AnimationRootNode]. Emitted when the [member anim_player] is changed.