Screen-position based textures

I’ve searched and searched and searched, but haven’t had any luck at finding anything like this.

Basically what I’m looking for, is a way to tie the position of a texture, no-matter what object it is placed on/where said object is, to the screen. Below is a video of a cartoon showing this off; I’ve seen many other games and shows do this, but this was the first one that came to mind.

[- YouTube][1]

If you look at the clothing in this cartoon (or various other elements), you can see that despite said object moving/animating however, the texture stays locked on a different position; causing other parts of the texture to instead be visible when they move around like such.

Anyone else have any ideas on how to accomplish this? I’m no expert programmer keep in mind, but an artist- but I know this is possible. I believe I’ve even seen it done in a Unity game in the past.

Thanks to anyone taking the time to read this/post.
[1]: - YouTube

You would just need to write a custom shader for it.

Normally a shader would have something like:
output.colour = Tex2D(_MainTex, input.uv);
Which basically says, look in the texture _MainTex and give me the colour at the coordinates specified by input.uv.

All you want is to replace input.uv with input.screenPosition, so that it looks at the texture according to screen position instead of the actual UVs of the model. Of course, before you can do that you’d have to calculate the screen position in the vertex shader.