I saw this video https://www.youtube.com/watch?v=ILckBH5JsrI where there was a fade to desktop effect at 0:40. How is that effect achieved, i.e. using SDDM, ksplash, etc. I want to replicate it using Compiz as my standalone window manager and SDDM using autologin for a flickerless login, and then integrate sddm with plymouth for a flickerless boot process as well. Currently, I'm using SDDM with autologin, but it's not fading to desktop, just jumps from black screen to desktop. OS is Arch.

There is a Desktop Effect in System Settings called "Login" which says "Smoothly fade to desktop when logging in", does that help?