Talk:Sky never changes in Doom II


Thanks go to sofaking for his Chocolate Doom bug report which lead to my discovering this, although apparently it's been noticed before. I *think* I've got my understanding of the behavior correct. Can someone run through a 30-level speedrun and confirm this is correct? The computer I'm using at the moment runs doom2.exe in DOSBox, but it's dog slow. Fraggle 22:43, 17 April 2006 (UTC)

This is correct, and it happens in Doom95 as well.  (You only have to do MAP11 through MAP29 to confirm the bug, not all 30 levels.)  When you say "speedrun", are you asking for a demo?  That would be pretty boring even compared to my normal output.   :>     Ryan W 18:11, 11 May 2006 (UTC)
It's still nice to be able to confirm that you can play through the entire game without the sky changing. All I want is confirmation that you can do this: watching a demo of the entire game being played (especially a speedrun) is sufficient to demonstrate this and likely to be significantly faster than playing through every level manually. Fraggle 19:42, 11 May 2006 (UTC)
Well, sort of.  On some levels, very little of the sky is ever exposed, and you might have to keep rewinding again and again in order be sure whether you're seeing SKY_1 or SKY_2.  I figured it would be faster to just play through it once in -nomonsters, so I could pause at the appropriate vantage points.    Ryan W 20:18, 11 May 2006 (UTC)
That's weird, I once did a doom 2 runthrough on prboom(with iddqd & idclip) before I knew the warp tricks, and I know the sky changed... --drake raider
Drake, that's because you used PrBoom. Only occurs in Vanilla. :>

-Wagi 15:45, 17 January 2008 (UTC)

This entry needs to be corrected. Fraggle reversed my corrections, but I'm sure he'll add them back once he does some proper testing. I knew it was wrong immediately as I've played either from the menu, warping, with the cheat, save-loading, and watching demos tons of times using Doom2 to this day, so the nature of the bug's performance (sky change is broken, using the sky from the first level loaded only, except when you start from the menu) is as familiar as eating and drinking to me. Who is like God? 14:08, 23 February 2008 (UTC)

Can you tell us the version of Doom in which you experienced this? I just played through Doom 2 v1.9 using DOSBox. I started a game from the menu in Ultra Violence and enabled god mode and no clipping to work my way to MAP12. The sky STILL didn't change. The linux source code also shows no sign of allowing a sky change after the game is launched from the menu. Zack 03:01, 25 February 2008 (UTC)
Um, the article claims that the bug is fixed in the released source.    Ryan W 03:12, 25 February 2008 (UTC)
On second glance at the source, yes, this is correct. However, I still see no evidence that starting the game from the menu could prevent the bug or cause it to behave differently. When a new game is set from the main menu, the same code is executed that would be executed anyway were the player to warp to MAP01. Zack 04:01, 25 February 2008 (UTC)
It's because of a function that is called when you load a game or start a new game, that is not called when you simply enter a new map from another level. Warping apparently causes different things to happen than simply exiting the level. I'll try to remember the function names when I get a chance to look at the source again. -Wagi 15:12, 25 February 2008 (UTC)
I've made a mistake! I had the idea it worked from the menu but I personally warp, load or record a lot when playing, besides watching many demos, and did some testing with various settings before editing and posting, except starting from the menu and reaching a transition point (which would have debunked my idea). I now changed the 3rd paragraph to make it clearer; now it reads more like a clarification of the implicit behavior surrounding the bug rather than as an exception of sorts.Who is like God? 01:35, 26 February 2008 (UTC)


Do any of the licensed ports (PSX, Saturn, GBA) exhibit this bug as well? Asdfsfs (talk) 00:36, 19 January 2015 (UTC)

PSX does not for sure because in PSX, the sky is controlled on a per-level basis via use of a particular sky flat - F_SKY1 through F_SKY9 are supported in that engine to select the proper sky for the map. It does not fully support more than one sky per level, however - at least one map (the equivalent of Doom II MAP07) has some improperly skied sectors but they do not appear incorrect in game. They get overridden in some manner I've not figured out. --Quasar (talk) 21:53, 19 January 2015 (UTC)