How can I assign an image texture gradient along a circlular ring?

Question

I was recently working on a project of modelling the Solar System. When it was time for Saturn I couldn't assign the rings texture on the model (Circle - rings of Saturn).

I couldn't unwrap the rings correctly. What is the best way for assigning the texture on the circular rings?

Rings texture

Desired ring effect

Answer 1

Assuming all your faces are quads already, first select a ingle face and unwrap it using the Reset option so the UVs become an orthogonal quad.

In Edit Mode select all your faces making sure you specifically click on the one you initially unwrapped, so it remains the active face.

Now unwrap it using the Follow Active Quads option. In the UV Image Editor turn on the option Constraint to Image Bounds under the UV menu.

Rotate your unwrapped faces 90º if necessary so their orientation follows the ring image as desired.

Move them so they fit to the 0,0 coordinate then using scale resize them so they completely fit within the image boundaries. The Constraint to Image Bounds option should make sure everything snaps into place easily.