system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Started watching Chowder on Netflix, how do animators do the static patterns that stay with the characters and such when they move in scene? (Like Chowders hat

I'm just really curious since its a cool technique I've noticed in other animated shows that I can't quite place in my memory at the moment.
gpt
It's actually quite simple. When doing graphic art you do a lot of what is called layer masking, where you basically put a shape over a layer (which can be a full screen for example) and tell the computer to hide all of the layer unless it falls under the shape in question. 

Just think of it like a transparent window, and the texture actually covers the whole screen, but you can only see it as the 'window' passes over it.