Skeleton for 2D characters and animated objects. Skeleton2D parents a hierarchy of [Bone2D] objects. It is a requirement of [Bone2D]. Skeleton2D holds a reference to the rest pose of its children and acts as a single point of access to its bones. To setup different types of inverse kinematics for the given Skeleton2D, a [SkeletonModificationStack2D] should be created. They can be applied by creating the desired number of modifications, which can be done by increasing [member SkeletonModificationStack2D.modification_count]. $DOCS_URL/tutorials/animation/2d_skeletons.html Executes all the modifications on the [SkeletonModificationStack2D], if the Skeleton3D has one assigned. Returns a [Bone2D] from the node hierarchy parented by Skeleton2D. The object to return is identified by the parameter [code]idx[/code]. Bones are indexed by descending the node hierarchy from top to bottom, adding the children of each branch before moving to the next sibling. Returns the number of [Bone2D] nodes in the node hierarchy parented by Skeleton2D. Returns the local pose override transform for [code]bone_idx[/code]. Returns the [SkeletonModificationStack2D] attached to this skeleton, if one exists. Returns the [RID] of a Skeleton2D instance. Sets the local pose transform, [code]pose[/code], for the bone at [code]bone_idx[/code]. [code]amount[/code] is the interpolation strength that will be used when applying the pose, and [code]persistent[/code] determines if the applied pose will remain. [b]Note:[/b] The pose transform needs to be a local transform relative to the [Bone2D] node at [code]bone_idx[/code]! Sets the [SkeletonModificationStack2D] attached to this skeleton. Emitted when the [Bone2D] setup attached to this skeletons changes. This is primarily used internally within the skeleton.