Things about Doom you just found out

I just realized that some triggers in Doom 64 needs you to pick up the item proper. While there's no problem with item secrets, but if you happen to have a full ammo stock (example, super shotgun secret and the first rocket launcher in MAP29: Outpost Omega) that weapon secret or monster spawn won't trigger.

 

 

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Apparently sprites disappear after very long distances in Software mode. Recently played Epic map05, and some of the dudes on the platforms became invisible when looking at them from near the starting area. Never noticed this in GL.

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38 minutes ago, Spectre01 said:

Apparently sprites disappear after very long distances in Software mode. Recently played Epic map05, and some of the dudes on the platforms became invisible when looking at them from near the starting area. Never noticed this in GL.

Could you post a picture please? I always use software mode and that's something I've never noticed.

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You might have run into the vissprite limit.

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39 minutes ago, Spectre01 said:

Apparently sprites disappear after very long distances in Software mode. Recently played Epic map05, and some of the dudes on the platforms became invisible when looking at them from near the starting area. Never noticed this in GL.

The limit is 8192 units, caused by the following in R_ProjectSprite

// too far off the side?
if (abs(tx)>(tz<<2))
  return;

tz is the projected distance of the sprite from the camera along the view vector. 8192=2^13 units in fixed_t is 2^13*2^16=2^29 as an int. So the shift up by two (i.e. multiply by four) takes it to 2^31, and you get integer wrap. So when tz > 8192*FRACUNIT, (tz<<2) is negative, and a negative can't be greater than a positive (abs(x) is absolute value, always positive)

>Gez has replied (show reply)

Without clicking on the notification I expect I've been beaten to the explanation, but submitting anyway.

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39 minutes ago, galileo31dos01 said:

Could you post a picture please? I always use software mode and that's something I've never noticed.

Sure! Here's the spot where the Pinkies are visible:

9517865AD85F1D49CCDC8181A419C51A59D4E07D

 

Take a few steps back, and they're gone!

D55FF2FC6967D7BC0BD3339AC31A3A24743B74DF

 

Edit: Interestingly enough, checking the builder shows a distance of around 5.5k units where this happens.

Edited by Spectre01
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I'm using version 2.5.1.4 and definitely can't see them from the railway tracks on my end. Interesting.

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Purposefully ignoring the drawing of far away sprites can improve performance massively, especially when there's tons of corpses to render. Even though it only needs to render a small handful of pixels, the setup time for each sprite adds up. So, maybe there's a setting that allows you to turn off distant sprites?

 

What I do know is that, if you look to the far right of that last picture, you can see an imp on a high ledge, and some fireballs, which look much further away than the pinkies, to me.

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Dunno if this is related, but I used to be able to get screenshots with most (all?) of the monsters removed when playing really highly populated maps (e.g. Nuts). Meanwhile, in the game I never saw them disappear.

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2 hours ago, Memfis said:

Dunno if this is related, but I used to be able to get screenshots with most (all?) of the monsters removed when playing really highly populated maps (e.g. Nuts). Meanwhile, in the game I never saw them disappear.

with prt-scr or the engine's built in screenshot thing?

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3 hours ago, Alfonzo said:

Icon of Sin's attack rate is halved on skills 1 and 2.

Also on UV there are two spawn cube launchers (iirc).

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On 07/12/2017 at 0:33 AM, Spectre01 said:

I'm using version 2.5.1.4 and definitely can't see them from the railway tracks on my end. Interesting.

Mystery solved! Turns out since 2.5.1.4 there was a fix applied relevant to sprite drawing in r4516/r4518. Going back to before that point reproduced your observation.

Spoiler

 


------------------------------------------------------------------------
r4516 | entryway | 2017-03-04 15:53:52 +0000 (Sat, 04 Mar 2017) | 6 lines

Fixed sprites dissapering on ludicrm.wad map03 because of integer overwlow in clipping code (floor height is 31656).

Replaced with ZDoom code which is more coorrect I hope

https://www.doomworld.com/vb/post/1723386

------------------------------------------------------------------------
r4517 | entryway | 2017-03-04 16:33:12 +0000 (Sat, 04 Mar 2017) | 2 lines

rever r4516

------------------------------------------------------------------------
r4518 | entryway | 2017-03-04 18:44:16 +0000 (Sat, 04 Mar 2017) | 6 lines

Another try to fix sprites dissapearing on ludicrm.wad map03 in software mode.

r4516 failed at non 4x3 aspects

Also I noticed that old code don't draw many tall red firesticks on start position on sunder.wad map10 (240 sprites instead of 400+)

------------------------------------------------------------------------
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2 hours ago, scifista42 said:

^ No, there are not.

Heh I guess I didn't recall correctly. Maybe it was one of the Final Doom episodes. I distinctly remember seeing two of them in a map30 somewhere.

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From wads I have to hand, boss spawners (type 89) which appear in single player on UV:

1   doom2.wad      MAP30
1   plutonia.wad   MAP30
1   tnt.wad        MAP30
1   300minvr.wad   MAP30
1   av.wad         MAP30
1   epic2.wad      MAP30
1   freedoom2.wad  MAP30
1   hr.wad         MAP32
1   mm.wad         MAP30
2   d2ino.wad      MAP30
2   jenesis.wad    MAP28
2   mm2.wad        MAP30
2   perdgate.wad   MAP30
2   pl2.wad        MAP30
2   requiem.wad    MAP23
2   requiem.wad    MAP30
3   cchest3.wad    MAP29
4   200minvr.wad   MAP30
4   cchest3.wad    MAP30
4   hr.wad         MAP30
4   jenesis.wad    MAP30
4   ksutra.wad     MAP30
5   1994tu.wad     MAP30
6   pl2.wad        MAP32
9   cchest2.wad    MAP30
9   hr2final.wad   MAP30
40  sodfinal.wad   MAP30

@Megalyth Despite the above count, you are correct: plutonia has two, but the second is flagged absent in single player.

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Wow, 40 in SoD. That must be insane. I never finished that set, I think I made it to map19.

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The best spawner map is clearly Experiencing Nirvana's. 

 

 

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8 hours ago, RjY said:

Mystery solved! Turns out since 2.5.1.4 there was a fix applied relevant to sprite drawing in r4516/r4518. Going back to before that point reproduced your observation.

Wow - good to know. That's for finding that. It's yet another Doom renderer bug caused by integer overflow!

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7 hours ago, RjY said:

From wads I have to hand, boss spawners (type 89) which appear in single player on UV:

what, no mock 2

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Icon of Sin's cube shooter uses the SS soldier's sprites, it's just invisible. Doom was secretly antifascist all along.

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DSPDIEHI, the sound the player make when he's brought to -50 health by the killing blow(super death) was not featured in Doom. I guess it was added to Doom II after the introduction of the new bestiary of mid-tier monsters, which could more easily trigger that death scream.

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13 hours ago, Uni said:

DSPDIEHI, the sound the player make when he's brought to -50 health by the killing blow(super death) was not featured in Doom. I guess it was added to Doom II after the introduction of the new bestiary of mid-tier monsters, which could more easily trigger that death scream.

Actually as far as I'm aware it's only the shareware version that is missing it.

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