@tgjessie: Perspective Correction is the name for a term that prevents texture warping when using both the x and y-axis, it wasn't utilized until around 1995 with games such as Dark Forces, developers didn't think to find a solution to that issue at the time since their intention was that you would only ever use horizontal scrolling, so this allowed walls and ceilings to be rendered as simpler and less taxing objects in the game engine.
I might be wrong on some of that, but tl;dr - it looks odd because they were never intended to be viewed at a different vertical angle.
Actually, one of the nice things about 2.5d (Wolf3d, Doom, etc) was that they all had perspective correct texturing, provided you were always looking ahead. The inability to look up and down in Doom felt restricting at the time though, so later games started shifting the screen up and down to simulate looking up and down. Naturally, this method doesn't produce an accurate 3D projection.
@icyeyes: Not quite. It probably uses the original data, but it's processing/interpolating the audio to make it sound less harsh, resulting in muffled audio. The same audio being played without any interpolation would produce harsher/crispier audio.
When using low quality recordings, it's a matter of preference: do you use the original sample points for more accurate sound, or do you interpolate them to make it sound less harsh at higher sample rates?
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