NuXCOM_90Percent , 8 hours ago

Just from the screenshots in the tweet/article:

I would argue that is less transparency and more overlaying the skybox texture. In the city map with the Pinky you can’t actually see anything behind that wall, you just see the skybox.

Could just be “bad” examples but this makes sense. My understanding is that PC DOOM tended to use additive geometry in these cases so that the skybox is literally just a bigass box around the map. Whereas I assume the Saturn version had to do some magic to fit everything and may have used a different technique. Hence the ability to just overlay that texture over everything.