I remember building Unreal maps as a teen. I didn't really understand bsp back then, and online discussions regarding mapping where full of cargo-culting weird

I remember building Unreal maps as a teen. I didn't really understand bsp back then, and online discussions regarding mapping where full of cargo-culting weird methods to avoid "bsp holes". They were basically holes in the level geometry that sometimes even only appeared at specific camera angles, and not just in the distance, sometimes right in the corner of the room you're standing in. There were also two sliders in the dialog where you rebuilt the bsp, but I forgot what they were called and at least back then didn't understand what they did anyways, but changing them slightly could resolve the issue - only so you'd realize there's now a new hole somewhere else after 5 minutes.