I'm creating an animation where regions of the brain light up and turn off, cued to video and sound. Many many keyframes of essentially "fade on / fade off" switches for each of the 6 highlighted regions.

I started keyframing the Mix Shader node FAC values using a transparent shader to "turn off" the highlight, but there are too many keyframes to do and it's getting out of hand.

This feels similar to NLA actions - drop "cerebellum on" action strips where I want to turn "on" the cerebellum; and more easily adjust timing and add transitions to suit video...

...but I'm not able to create an action strip of a material! Is this possible? Is there a trick to do it?

I then thought of using an empty's x location to drive the FAC value of the mix node in the material and create action strips of the empty, but don't know how... does this require a Python script?

Is this something the fabled animation nodes could help resolve?


1 Answer 1


Found the answer: Fade in action applicable to all objects (in cycles)

Keyframe the object's pass index from 0 to 100, use the object info node:object index output, connect to math(multiply) node with value of .01, connect to FAC value input on mix node.The object's pass index gets recorded in the NLA editor, so I have my action strip!


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .