To create a Relations constraint:
The Navigator window displays the Constraint settings, and the constraint is added to the Scene browser.
A new folder named “Constraints” appears in the Scene browser, with the new folder named Relations added, and the Navigator window displays the Relations Constraint settings.
You can also Alt-drag materials, objects, and devices from the Scene browser or models from the Viewer window into the Relations pane.
If a converter is needed in order to correctly join the constraint, it is added automatically.