What is this type of light called, and how do you make it?

the light that is divided into sections like this
Skærmbillede 2024-08-01 163442
is it just a post processing effects?

That’s a defect called “banding” and you can usually get that if the color bit depth is reduced.

where is that in UE4

It’s not a thing you can easily control. Banding is an artifact that’s the product of energy values getting compressed, and it’s something that a lot of development work has gone into fighting. There are ways of creating the appearance of banding, but it really depends on what you what to do with it. I take it you want a PPV effect that creates the look of banded lighting, CRT-esque?

I don’t know about CRT-esque, but yes a post processing effect, but is banding can be achieved without maybe it’s better for performance idk

I’ve tried using LUT but can’t quite get the results I want