In this video, Simon Turner goes over how to achieve the "jittery" or "electric" effect he used on the lightbulb's face in his animation. It's about displacement mapping a moving texture to a text/shape/etc.
Transcript:
In this tutorial, I'm just going to show you how to do that jittering effect that I had on my light bulb's face. People use this in text all the time to make it look hand-drawn and jittering. You can put it on any illustration. It's basically a simple thing using displacement maps. It's super easy.
So for this, we just have a blank after-effects composition, a white background, nothing fancy. And for the sake of the tutorial, we'll just create a text layer, and we'll just type in text, keep it easy. And we might as well align it vertically and horizontally, just so it's easier. Once you have this, you're actually going to want to create another new layer but make sure it's a solid. And we can call it whatever. I'm going to call it map because that's where the displacement map's actually going to be. Just make sure it's the same resolution as your composition, things like that.
So once we have this, we're actually going to be coming up to effects and typing in fractal noise. And this is what's going to give it the map to make it jittery and sporadic. You can see, it just looks like this. You can either drag it on top of your composition right here or in the layers over here. I just put it right here. And basically we're going to come over to evolution options, and where it says random seed, we have to keyframe it, so every second it'll change 10 times in that second so it looks erratic just how it was in my animation. So just you're going to have to alt-click the keyframe right here, and that's going to bring up a text box. And easiest way to do this is just to type time asterisk 10.
And that's basically saying every second, it's going to rotate and change 10 times. And then once you have that, just click off of it. So if I play this, you can see it move super fast. After you're done with that, you're going to want to right-click this solid. And you're going to want to recompose this to a new composition. So just click on this middle one right here. Check part, yeah, you see.
So once you have that, you are actually going to want to come over here, hide this layer first, actually hide that layer, and you're going to want to find a displacement map, which is how the whole thing works. So you just click and drag this onto your text layer or onto the text itself. Just drag it. All right, now once we have this, you can see it looks a little weird, but that'll go away because the displacement map layers on the text. But it should be on the map comp too, which is the solid layer that we just created.
And once we do that, if we play, you can see that it displaces that animation we made with the fractal noise, and it looks jittery and cool. And you can make it faster, slower. You can play with it a ton, but yeah, that's the gist of it. That's a pretty simple effect. I've seen a ton of people do it with more like hand-drawn type so it looks like it's being sketched like over and over. It's super easy, and yeah, that's it.