MAP12 Error

I just noticed that in MAP12 of DOOM 2, if you try to shoot one of the roaming Arachnotrons with your back directly against the outer boundary of the map, you'll hit the low ceiling that (I assume) was put in to make that outer boundary wall not ridiculously high. Unfortunately, the Arachnotron's shots can still hit you.

Someone has probably already noticed this, but I was surprised to find it effect my actual gameplay only just now, after years of playing that level and not noticing it. Has it affected anyone else's attempt at MAP12?

Never affected me.. Didn't even know that could happen. I don't really play Map12 all that often though..

The same thing happens in E4M6. When you go up to the secret that takes you to the soulsphere you see at the beginning, the caco surrounded by the lava-moat can't hit you. However, you can still use hitscan weapons to kill him.

It doesn't seem very common. From what location in particular? I just tried and I think one shot did what you describe.

You might be able to illustrate it with a demo, or at least a screen shot, to show the location from where you get the effect.

I'm pretty sure I've done that at least once in the very distant past. Actually The Factory used to be my favorite map! Used to play from scratch (in vanilla Doom) all the time when I was but a wee novice Doom addict...

If you can't see monsters, your shots would go forward, and they wouldn't see you either. I think you're describing a phenomenon where bullets fizzle just in front of you, and it happens a lot in MAP12.

printz said:

I think you're describing a phenomenon where bullets fizzle just in front of you, and it happens a lot in MAP12.

Exactly

myk said:

You might be able to illustrate it with a demo, or at least a screen shot, to show the location from where you get the effect.

Here's a demo: http://www.mediafire.com/?sharekey=bb41f5cc0460cee8e7ba8e3c6e11ce20e04e75f6e8ebb871

Ah, that phenomenon. If you look at Map12 in an editor you'll see the sectors in question don't have low heights (0/96, 0/208 and 80/208.) The bug has got an article in the Doom wiki, though it needs a description and technical information: Hitscan attacks hit invisible barriers in large open areas.

And no one knows what causes this?

One guy on the talk page believes it's caused by an error in the map's nodes.

EDIT: See this thread.

Even though I don't quite understand the whole "linedef 0" thing (I'm not a programmer), I'm willing to believe that's the cause of things like your own bullets poofing in front of you on Map12 (near the outermost edge) and E3m6. However I've also definitely known about the "2048" hitscan limit for some time (Has Zdoom removed that?) which I know is completely different from this issue, yet it exists nonetheless (at least in vanilla Doom last I played).