This should not be hard (rough version of it) to make.
Get world position, substract from it camera position (you may update that as parameter trough blueprints and dynamic instanced material). Then calculate length of that difference.
Actually I don’t think I went into the World Position Offset details in the thread (just World Origin Shifting, another unrelated concept I was trying to tackle) – I had intended to, sorry
I’ll see if I can come up with a breakdown on my specific WPO implementation and add a post in that thread. In the meantime I think this is what got me pointed in the right direction:
Beware that WPO isn’t currently supported by any raytracing tech in UE 4.x, or Nanite/Lumen in UE 5, and may have some other rendering gotchas that I can’t recall off the top of my head (I have pages of notes for that project that I’ll have to sift through).
You inspire me acatelept. I eagerly await the possible (but not inevitable) WPO info if you are able to shed some light on it. Your project introduced a lot of concepts to me that I would have never thought about initially, so thank you for posting that thread