Bent Normals

Right since the 4.17 release I’ve seen no other information on this or how to do it. So I’m asking you for help

What is a bent normal for starters?

From what I’ve seen my best guess is it’s a world space normal map, am I right? If not what is it and how If I were to bake out maps for it in Substance Painter would I go about doing it.

Next how I do I set this is up in engine and what is it?

Is it a material function, post process affect or Engine rendering function?

Please can someone enlighten me to how this done.

Bent normals are storing average direction from which ambient light comes.

Thank you!