Talk:Mancubus fireball clipping

I'm pretty sure this bug is caused by the very thin projectile (width = 2*6 = 12) with very fast speed (20 pixels per tic). If it's 12 wide and moves orthogonally at 20 p/t, it will jump over 8 other points, those possibly including the wall. That's okay, but it means they CANNOT pass through any default Doom solid things. They're all 16 or more units wide, they can't be jumped by the Manc fireball.

Or am I actually wrong? Printz 22:42, 7 February 2008 (UTC)


 * The wording seems imprecise, as it is intended to apply to linedefs, not Things (see the example demo). Opinions vary as to whether a complete lack of code excerpts in a bug article automatically makes it a stub.   :>     Ryan W 20:20, 8 February 2008 (UTC)

Source code
It appears that Lee Killough does get the credit for fixing (judging from MBF readme file, and from the timestamp in sourcecode comment). Anyone interested, look into MBF source - P_XYMovement in p_mobj.c (line 175 and beyond) - and attempt to outline this, as for me, it's completely incomprehensible. --Unmaker 15:56, 28 July 2012 (UTC)

Nice pic
That's a really good pic of the phenomenon. I intend to firm up some of the technical details about this glitch and get that stub header taken down soon. --Quasar 21:55, 3 October 2013 (UTC)

Fireballs from other monsters going through walls
I found a video on Youtube where an Imp's fireball passes through a wall. This is on version 1.2, but it is very hard to reproduce and videos exhibiting this bug are scarce. I saw it only one time when playing on nightmare on E1M4 of The Ultimate Doom when tons of Imps were shooting fireballs at me and I hid the other side of a corner.

The video is called "Random DooM WAD - 0.5 stars" from NoMac90.

It occurs at 4:50, it's hard to see because it's quick. Even a Cacodemon's fireball went through the wall.

--AXDOOM 7:37, 15 October 2013 (UTC)

The cause of this bug: source code
Hi people,

I was looking at a change in DoomRetro's source code (http://git.io/gwcQfQ) and I saw this interesting comment.

In the original Doom's source code, the condition doesn't check for a negative MAXMOVE value. I still have to confirm this, because the code before this change is different, so I'll wait until the next DoomRetro release.