Animating materials for blinking effect I would like to animate objects in my scene so they appear to blink, each at a different time. I created a cycles material that mixes two shaders (one in non-blink mode, the other in blink mode), and I can set keyframes for the mix shader factor parameter. A couple of problems...

It seems like each blinking element needs its own copy of the blinking material, so I can change the keyframes so they have different on/off times. If I have 8 blinking elements, I need 8 materials, and I need to modify each one so they turn on/off at different times. Is there a more efficient way to animate multiple objects this way with fewer materials?

I want the blinking action to be repetitive, so I don't have to define many on/off keyframes in a long animation. AFAIK, I cannot use the graph editor and f-curves since node parameters don't appear in the editor. Is there a way to "loop" the blinking for a material? Edit: I discovered that I can add the mix shader/factor property to the "Keying Set", so it then appears in the dope sheet editor and graph editor. I can then add a f-curve modifier to it to make it repeat.

In this image, you can see one "comma" blinking on, and the others off. And you can see the material I'm using for it.
It's hacky, and annoying if you want to use it for its intended purpose, but you can animate (or drive) the Pass Index of an object, and access it through an Object Info Input node.

Using a setup like this..



In this example, the Pass Index of each object is animated cyclically, with step-wise interpolation, from 0 to 4. This can yield an sequence like the one below..



..with all the objects sharing the same material, and their cyclic Pass Index animations offset in the dope sheet.



Following stav's suggestion of a rearrangement, here's a version in which the Pass Index is not animated, but used to set the phase: the number of frames a color cycle is offset for the object bearing it. (See comments)



The 'Frame No.' and 'Cycle Period' nodes are both Input > Value nodes, with the value in  'Frame No.' keyframed with a linear interpolation to match the frame number of the animation. The Color Ramp will be swept in the number of frames in the 'Period' node. In this case, the Pass indices of the groups of objects are 0,4 and 8, to get a trailing 1-on, 2-off effect.