The mystery of the missing secrets.

[NuMetalManiak]

Hi, no idea if this is in the correct subforum but move it if it isn't

 

Recently I just documented info on TVR! MAP05's secrets on Doomwiki while replaying the wad, and the one thing I have noticed is that only 3 out of 4 secrets is possible in this particular map. The edited page if you wanna see. I have found out where and how to get each secret on the rest of the secrets, but upon analyzing the map in Doom Builder and even DEU (which I think was what TV used to make the level with), I have not found any extra info regarding the missing secret on this particular map. Searching all sectors of type 9 reveals only three of them, and after figuring out what to do with the DEU editor, nothing else groundbreaking apart from a rather strange difference in sector numbers (also documented). I know other maps have this issue, notable MAP20 in the same megawad has 2 secrets but only one is found. And DOT.wad MAP07 has 3 secrets, but only 1 is actually accessible at all.

 

The thing I wanna ask is, does this phenomena happen when a secret sector is deleted or something? I am really not sure what this is exactly.

[Edward850]

No. Sector counts are absolute, based on the number of flagged sectors.

[hawkwind]

This may well be a DEU bug, and not a map bug per-se.

[Edward850]

Upon further inspection: Indeed a DEU bug. The map has unused sectors, likely because of the how some lines were deleted, and one of them happens to be a secret flagged sector. Modern map editors will automatically discard such sectors (as they can't be edited without lines to represent them), but Doom itself doesn't care as sectors are simply references, so the flagged sector still exists.

 

This is also why the sector counts change when you open the map, as the editor first discards such sectors while loading.

Edited July 27, 2017 by Edward850

[EffinghamHuffnagel]

I call it a 'ghost sector' error. Either a sector tagged as secret was deleted, which leaves an unscorable secret tag in grey space, or accidentally left open and then deleted/re-drawn on top of itself, which can leave a sector as two secrets, but only one of which can be scored (technically found as two sectors/secrets in a search). The second is very rare. I've only seen it a couple of times. I'm not sure what builder causes this, but I fixed the maps in my copy of TVR! by opening each one in GZDoomBuilder, changing something, changing it back (not using Ctrl-Z Undo), and then saving the map, which re-builds it. GZDoomBuilder has an issue; it discards unused sectors/linedefs/etc. when you open a map, but it doesn't actually save those changes (even if you hit Save) unless you've actually changed a sector/linedef/object property in the map.

 

BTW, it's not just the secret sector property that can be 'ghosted'. There's plenty of times I've clipped through a map's grey space and started taking damage from nothing.

 

BTW2, does the wiki mention TVR! MAP01's unscorable secret? You can grab the armor, but you can't score the secret because the sector you have to enter is only 44 units high.

[Edward850]

5 minutes ago, EffinghamHuffnagel said:

BTW, it's not just the secret sector property that can be 'ghosted'. There's plenty of times I've clipped through a map's grey space and started taking damage from nothing.

That has nothing to do with what's going on here, that's just how Doom's BSP works. It's impossible to not be in a sector (there is no void as far as object collision is concerned) as all the BSP does is find out the most logical sector you should be in based on the divisions of other sectors, and if you are outside the playable map that division will tend to be whatever sector is nearest to your position.

 

In fact, it's impossible to be in a sector with no lines. It's not part of the BSP, and thus the engine can't ever place you in it.

[EffinghamHuffnagel]

Ah. Didn't realize that. Thank you.  That also explains why I've scored secrets in grey space from being near a secret sector, but never entering it.

[Grazza]

On a related topic:

https://www.doomworld.com/forum/topic/34665-a-very-strange-engine-bug-demo-included/

https://www.doomworld.com/forum/topic/56678-more-than-100-secrets/

 

 

[Xeriphas1994]

3 hours ago, Edward850 said:

The map has unused sectors, likely because of the how some lines were deleted, and one of them happens to be a secret flagged sector. Modern map editors will automatically discard such sectors (as they can't be edited without lines to represent them), but Doom itself doesn't care as sectors are simply references, so the flagged sector still exists.

 

Also a bug in those modern editors, FTR, that it happens silently and non-optionally. Fine for a WIP, perhaps, where the extra data is just clutter, but when analyzing old maps it makes it more difficult to figure out what the author was doing. In a worst case, special effects can be broken. Even making a thread to ask what happened is slippery, because the ID numbers change. I assume the situation is similar for other purged resources, e.g. things with no skill levels flagged.

 

I will file issues as soon as I have a supported OS for testing (otherwise the developers tend to close reports as invalid).

[Edward850]

30 minutes ago, Xeriphas1994 said:

things with no skill levels flagged

These are still valid objects to a map editor, there's no reason they would ever be auto pruned. Sectors and sidedefs are the only things that would be, as they would be otherwise permanently inaccessible.

[Arctangent]

1 hour ago, Xeriphas1994 said:

 

Also a bug in those modern editors, FTR, that it happens silently and non-optionally.

It's kinda impossible for an intentional feature to be a bug.

[NuMetalManiak]

7 hours ago, EffinghamHuffnagel said:

BTW2, does the wiki mention TVR! MAP01's unscorable secret? You can grab the armor, but you can't score the secret because the sector you have to enter is only 44 units high.

I was not specifically referring to this secret as the secret sector is actually there (even though yes, the sector itself is inaccessible). I was referring to MAP05 and how only 3 of 4 secrets were both accessible visible while the last one does not seem to be accessible by any means. Others here seem to have given me what I know so thanks everyone.