Its basically a script which modifies your perspective of the world so that if you were wearing a virtual reality headset, it would look really damn good.
In First Person, your body is visible.
Looking downward makes your character bend over and vice-versa upwards, and your camera remains snapped to your head while it does this.
You can even do a /e dance and see the motion and your arms moving.
Check it out here:
A video for those of you who are too lazy lol:
This is done in a non-hacky way. You can put this script into any game and it should work perfectly. This makes it pretty easy to setup a first person shooter game. The script is located in the Starterpack of the place.
You should make a web API, which when given a face decal, guesstimates the best position for a camera. Then you position the camera there, so it looks like you’re actually looking out of your eyes.