Contains a [Curve3D] path for [PathFollow] nodes to follow. Can have [PathFollow] child nodes moving along the [Curve3D]. See [PathFollow] for more information on the usage. Note that the path is considered as relative to the moved nodes (children of [PathFollow]). As such, the curve should usually start with a zero vector [code](0, 0, 0)[/code]. A [Curve3D] describing the path. Emitted when the [member curve] changes.