Targeted Cameras and Lights
This <extra> at the <camera> or <light> level defines a targeted camera or light. It does not instantiate the target scene node, so that it is mutually exclusive with multiple camera and light instances. While the camera node may include rotation transforms, only the roll and translation should affect the final placement of the camera and light, while the orientation is determined by the relative position of the targeted scene node.
||The url of the scene node target.
< !-- It is suggested that this node be a 'locator': some transforms, no instances and child nodes. -- >