A modification that applies the transforms of [PhysicalBone2D] nodes to [Bone2D] nodes. This modification takes the transforms of [PhysicalBone2D] nodes and applies them to [Bone2D] nodes. This allows the [Bone2D] nodes to react to physics thanks to the linked [PhysicalBone2D] nodes. Empties the list of [PhysicalBone2D] nodes and populates it will all [PhysicalBone2D] nodes that are children of the [Skeleton2D]. Returns the [PhysicalBone2D] node at [code]joint_idx[/code]. Sets the [PhysicalBone2D] node at [code]joint_idx[/code]. [b]Note:[/b] This is just the index used for this modification, not the bone index used in the [Skeleton2D]. Tell the [PhysicalBone2D] nodes to start simulating and interacting with the physics world. Optionally, an array of bone names can be passed to this function, and that will cause only [PhysicalBone2D] nodes with those names to start simulating. Tell the [PhysicalBone2D] nodes to stop simulating and interacting with the physics world. Optionally, an array of bone names can be passed to this function, and that will cause only [PhysicalBone2D] nodes with those names to stop simulating. The amount of [PhysicalBone2D] nodes linked in this modification.