Here is an example of using a gradient to control the threshold on transparency on Z-axis as explained in this video.
I can animate the location of the colors in the gradient:
But I want to use a grayscale bitmap as a pattern to follow for the transition. This image could work as a "clock" transition.
Here is a primitive attempt with curves:
I can not animate the RGB curves node. Here is a manual animation moving the curves for each frame:
And here is another manual animation using this other texture:
How can I combine a bitmap with a gradient to control the threshold?