I'm making an animation of Solar system and shadows of all planets are shown, except Saturns rings which have no shadows¸, although there's no light from the Sun coming to the certain parts of the rings. For Saturns rings I used torus.
But when I position the torus at a certain angle, it's completely dark.
This is torus' node tree.
And this is the node tree for every other planet.
My render engine is Cycles.
What could be the cause?