Currently can't progress in the mod because I can't find any of the scrap in the subway.

It took me a while to realize I could break down doors by shooting them, but now I've been exploring rooms for about an hour and haven't found any new resource. I'm not sure if this part of the mod is unfinished or if I just missed something, but I may have to uninstall as it's blocking progress for the game in general. I was able to enter the tunnels as soon as I touched down on Fulgora, before finishing Electromagnetic Plating. I don't know why, the game just let me in without unlocking the technology.

I do like the idea so far, exploring room by room was interesting.

Are you on an old version? That tunneling bug was fixed a while ago so you may just need to update. Try looking under the Fulgoran Vault ruins for the scrap. If you are on the surface near one (in the same chunk) and tunnel down you should find the scrap.

Finally found one now that I have an understanding of where to look.

Recommendation: Exploration through the underground is very slow, interesting at first, but quickly becomes a slough of breaking down doors and clearing rooms. It may have gone faster if I was better equipped, but it'd be much slower than over world exploration. There needs to be some sort of clue as to where to look because 'in the same locations as the vault' isn't immediately obvious. There's no indication that there's any correlation between what's on the surface and the subterranean map.

1) An in game tutorial would solve this, but also instantly remove the aspect of searching and discovery

2) The Display Panel can have text in the notes or even displayed. You could have hints in a sort of text log about where to look. Or you could even use the ↑↓→← arrows as an indicator toward the nearest patch. The only downside I see here is not a lot of players know about Display Panels text, and those buildings might get destroyed in combat.

I still can't find any. How rare is it? What does it even look like? I assume "underneath the surface vaults" means I need to find a "Fulgoran vault ruin (entity)" on the surface and tunnel down from there, but I'm not finding anything special under them. Some are above rooms full of monsters, others are above random tunnel sections. I was slowly clearing room to room at first but when I wasn't finding anything I started flying out of bounds to speed it up, but still nothing. I even tried spam placing miners around in case I found some but didn't recognize it.

I do have a lot of other mods installed. Is it possible that one is breaking the world generation for the subway "planet"? I only have one that is supposed to alter world generation but it's supposed to be limited to nauvis. I've been to all the other undergrounds and nauvis/vulcanis/gleba all correctly have their unique resources, so if it's a mod conflict then it's only affecting the subway.

I recorded a video and uploaded it as a gif here: https://imgur.com/a/lxoD9cv and that's only a fraction of the area I've revealed.

currently have all six subterranio mods on 0.1.21. I installed them on a save file that had already been to all the inner planets.

I still can't find any. How rare is it? What does it even look like?

For me it was a normal room that had a giant square of resources in the middle, nothing fancy, just a nearly infinite patch of the stuff. Red and Blue were right next to eachother. It was the Giant Fulgora Rune which is the same one you find to unlock tech normally. The patch was not directly under it but somewhere nearby, it may be hard to find if you've already picked up the site.

Ok I didn't look at the video you posted until now: You should have found one, so my guess is they're not 100% guaranteed to spawn. Also you have some tile layouts that I don't so I might be on an old version.

I still can't find any. How rare is it? What does it even look like? I assume "underneath the surface vaults" means I need to find a "Fulgoran vault ruin (entity)" on the surface and tunnel down from there, but I'm not finding anything special under them. Some are above rooms full of monsters, others are above random tunnel sections. I was slowly clearing room to room at first but when I wasn't finding anything I started flying out of bounds to speed it up, but still nothing. I even tried spam placing miners around in case I found some but didn't recognize it.

I do have a lot of other mods installed. Is it possible that one is breaking the world generation for the subway "planet"? I only have one that is supposed to alter world generation but it's supposed to be limited to nauvis. I've been to all the other undergrounds and nauvis/vulcanis/gleba all correctly have their unique resources, so if it's a mod conflict then it's only affecting the subway.

I recorded a video and uploaded it as a gif here: https://imgur.com/a/lxoD9cv and that's only a fraction of the area I've revealed.

currently have all six subterranio mods on 0.1.21. I installed them on a save file that had already been to all the inner planets.

Based on that video you absolutely should have found one underneath all those ruins. Is there an easy way you could send me that save file and/or list of mods? I'd be interested in debugging that if possible. The scrap types are supposed to be 100% guaranteed to spawn under the ruins so I wonder if there is a bug in my code.

Echoing what Arashidrgn said, it will be super obvious when you find one.

In the meantime, assuming you haven't made any progress on the Fulgoran underground, you might want to go into editor mode and delete the underground surface, then try tunnelling down again. There is a fair amount of state-tracking needed to generate the underground rooms, and if that gets out of sync with other mods being added it might cause issues. Deleting the surface resets the state so things can re-generate fresh.

is there an easy way you could send me that save file and/or list of mods? I'd be interested in debugging that if possible.

The zip file is 108 MB. https://drive.google.com/file/d/1CD8Z0P4wrCuYfoKdWKlmbQjsCbWgKMfo/view?usp=sharing Yes, it's a hundred meg zip file with a nondescriptive name from a stranger on the internet, but I swear I just copied it directly from the factorio save folder. I understand if you want to steer clear (which technically you should for safety).

Here's a screenshot of the modlist https://imgur.com/a/u9v50hG everything is up to date according to the updates tab in the in-game mod manager. In case something jumps out at you as "obviously this one is the issue!".

you might want to go into editor mode and delete the underground surface, then try tunnelling down again.

okay just tried that, no change.

I've never used the editor before, but now that I'm poking around I noticed I can just place my own patch of scrap. There are five different types of scrap in the editor, but the tech tree seems to imply only mixed type 1 and mixed type 2 are mined while the others are crafted. If I want it to be an average amount, what should I place? I guess a rectangle of each mixed type in a room, with very high richness?

The patches under the vaults are about 16M each, which should last a very long time. Just the mixed type 1 and 2 will be enough to do everything

cool, thanks. now I can actually progress. already planning how I'll restore the rails....

Good news, there was a bug that is fixed now in subterranio-fulgora v0.1.22! You should be able to download that and any newly generated underground fulgoran vaults will be there.

Note that "newly generated" can be a bit further out than just the nearest unrevealed chunks. Many of those unrevealed chunks have already been "generated" just not shown yet. But if you explore a ways out underground you should find vaults. The other (more drastic) option would be to delete and re-generate your Fulgoran underground if you aren't too far in yet.

Do you remember if you added the Subterranio mods to your save after you had been to Fulgora already? That seems to have played a part in the bug.

Nevermind, I just saw your previous reply again:

I installed them on a save file that had already been to all the inner planets.

So that helps explain what was going on