Okay - I'll admit I don't much like the way the ring-disc objects look on that one. So after a bit of work, I got them around a planet in the sky. The planet casts its shadow on the rings and the rings cast shadows on the planet. There is one catch however. In order to make the rings visible at various angles, I had to adjust their opacity and color. Under certain lighting angles, some weird striping occurs in the planet's shadow. But I think it's not too bad at all.