In the scene I’m doing, all the characters are contained within electrical bubbles. Here is how the effect is done.
First, I create a file in Photoshop (4000px x 4000px) with a black background and a faint circle that will serve as a guide. Then, on a new layer, I draw the first frame of the electrical arc on the left of the circle guide.
I draw each animation frame on a new layer on top of the previous one. I reduce the opacity of the previous layers as I go to create a skin onion effect so that I know where I’m going with the animation. Going straight ahead, I create 37 drawings on 37 individual layers all contained within a single Photoshop file. Once all the animation is done. I save each layer as a seperate PNG file, named like this: Electrical_01.png, Electrical_02.png, etc.
I then bring those files in a compositing software (in this case, Animo), and add some blur and re-render them as a new PNG image sequence (see video below).
Then, I duplicate the animation several time, starting at various points of a 48 frame cycle. Each duplicated animation is rotated a different way, creating the illusion of a sphere (see video below).