@theblackhole, yep i dig it, i had moved the camera to the center of planet with ring, i understood that the distance shader node needs it to stop populating but i get a weird disribution of rocks inside the ring (not rings of rocks like saturn), in fact i am gonna test the cloud layer trick that seems lighter on resources (no pop objects), but tricky also to adapt to a specific planet, by the way thanks for your advices and contribution to this site & software
@jbest fog is just a default cumulus layer with a very low altitude and density
