EDIT:
So I figured out what changed. I had somehow accidentally changed the material of the planes to “Opaque” instead of “Translucent”. Switching it back fixed the way it looked, however I would still like to be able to render translucent materials with this dense fog. The solution I found for that was “Compute Fog Per Pixel”. I’m leaving this post hear because that option does not fix the strange rendering issues when things overlap as seen in the last image. That seems like buggy behavior to me.
I made a new post-processing material (right clicked in content browser and made it, so it wasn’t being used anywhere) and after closing the material editor window, I noticed that the fog was less dense than it was supposed to be. Then, when I moved the camera, the entire scene eventually became solid fog, but then past a distance, the scene begins to come back.
How it looked before:
How it looks now:
Moving further:
Everything is fog:
And then it comes back:
Furthermore, if I move the planes in the world, their appearance changes:
They fully “dissappear” at the same distance the camera does, but they come back once they get near the end:
Lastly, I turned the bottom plane sideways and now things look like this in the editor:
The plane that looks “on top” of everything is below/behind, and the textures that are supposed to be in front of it are rendering on the camera. Did I somehow accidentally disable depth testing? What on earth is going on here?