Doom All-Ghost effect glitch

Описание: During one of my doom 2 nightmare attempts I experienced a very rare glitch in doom, I uploaded this since I assume not too many people know about it and it's kind of funny. It's a bit of a combination of everything getting noclip\idclip and not being able to deal or take damage with projectiles\hitscan.

This is the glitch named All-ghost effect, in my countless hours of playing doom I've only come across this 3 times. No cheats or modifications to doom of any kind are used, the video is made by playing back a demo I recorded, the demo was recorded in a sourceport which is compatible with the original dos version, so everything seen here can happen in the original dos version too.

This is also playing on nightmare difficulty, so I can't use any cheats like IDDQD, IDFA or IDCLIP. Monsters are able to damage me with melee attacks, but not with projectiles or hitscan. When you turn into a ghost you cannot activate switches or teleporters, you can kind of see that I tried to hit the exit switch, but it didn't work :)

Luckily this was only the second map, if this happens during a run then there is nothing I can do... except run around and have some fun with it.

Here is a description from the doom wiki about this glitch, http://doomwiki.org/wiki/Ghost_monster :

"In extremely rare cases, a memory overflow can occur which causes all things, including players and monsters, to become ghosts. In deathmatch play, this phenomenon is termed the DM no-clipping bug. One such way to cause this is when a hitscan attack, or a BFG tracer crosses over more than 128 linedefs/things at once, causing an intercept overflow. Such an overflow can be produced, somewhat awkwardly but quite reliably, for example, by shooting a hitscan weapon over a large amount of corpses and pickups all lined-up in a row.

This bug can happen in all Doom engine games except Strife, where a fix was implemented to stop progression of tracers when the intercepts array is full. In versions of Doom up to 1.2, and in Heretic and Hexen, it is also possible for line-of-sight checks to trigger the glitch, as a tracer-like algorithm is used for line-of-sight checking in those games which utilizes the same intercept array. "