In Action, a ray is a child of a light. Multiple lights can be parented to the same Rays object.
To add a ray to the scene.
A Rays object is added to the schematic. In Result view, you can see the ray.
If there is only one light in the scene, the rays node is automatically connected to it. If there are several lights in the scene, select the light in the schematic that you want parented to the rays node before added the rays node. Otherwise, you can parent the rays node to the light or lights manually in the schematic.
Similar to the workflow of the Lens Flare, you can add texture components to a rays node to enhance the effect.