I've been working on this map on and off for the last few months and I recently added a small section where you interact with a computer (some tagged linedefs with a computer texture) and it lowers this section in the room revealing a keycard and a hell knight which are placed on a sector that's raised slightly above the floor... and that sector has a sort of Hall of Mirrors effect for some reason and I don't know how to fix it.
I've provided a few screenshots which should hopefully help.
The map is in DOOM II format.
I don't know why but when I tried making an outdoor area to end the level I got stuck with this...
if anyone can explain what's going on and how to fix it I'll greatly appreciate it, I'm editing this in DOOM II format.