Play effect on whole desktop on shutdown

[JosiahFu]

The Idea

I'm not sure if this is really difficult or out of scope, but it would be cool if when you shut down (from the GNOME menu at least, hooking into systemd would be harder), a specified animation displays on the whole desktop. For example, selecting the default fire effect then shutting down would cause your entire screen including the panel and wallpaper to burn away.

This would probably require another setting for an image or solid color background.

The Alternatives

I guess one could hack together a script to screenshot the desktop, display a fullscreen image, then close it with that effect?