Tes4Mod talk:Formid

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[edit] Credit to Ghostwheel/PhoenixAmon

Going over some old pages, I just realized that Ghostwheel was the first one to realize the Mod Isolation problem. I just wish that he had explained himself a little more. Here's his original comment from the Tes4Mod:Vs. Morrowind page and my mostly-missing-the-point response.

It looks like new ESM/ESP format uses 4-byte Form ID (using TES CS terminology) to store object references (e.g. SCRI field in many records). While this is more efficient, it looks like it has an unfortunate side effect that one (ESP) plugin cannot be dependent and reference objects from another (ESP) plugin - it can only reference objects defined in (ESM) master files. --Ghostwheel

While Morrowind doesn't have reference variables in scripts, it does use references internally -- and they're also four bytes. First three bytes are the object id (a long with the last byte chopped off, I think), last byte is mod index number (0=save game, 1-255 corresponds to load order of mod). See Wrye Notes: Doubling Explained for more info. Of course, Oblivion doesn't have to follow the same scheme -- it might hash the number or something like that. OTOH, if Oblivion does follow the same scheme... Eeep! Given the extensive use of references, worse problems then doubling might appear frequently.

Note that there's a distinction between creating mods, and playing mods. Mods in TESCS 3 don't remember other mods, and so can't modify their references. Discussion above is for playing. --Wrye 19:39, 28 March 2006 (EST)

Anyway, I missed the point enough that I had forgotten Ghostwheel's comment when I wrote my formid paper. My bad. (Next time, Ghostwheel, kick me when I make a mistake like that!) --Wrye 23:06, 2 May 2006 (EDT)

PhoenixAmon (Book Jackets, Landmarks, etc.) also reports having described the problem a week or so after Oblivion was released (about a month after I wrote about it). Since I later found one one of his mods good enough to steal, I'm going to believe that claim. Gotta yell louder guys, or we're not going to hear you. :) --Wrye 00:11, 15 December 2006 (EST)

[edit] Bogus Master References

Khadir added a note which I'm moving from the article page to here:

An ESP may have both new objects with a native modindex (usually '01'), as well as new objects with global modindex ('00'). The latter are used as-is by the engine, thus being, for all intents and purposes, static - the same as if they'd originate in Oblivion.esm. The drawbacks are the fact that you can neither create nor edit such ESPs in the CS4, and the potential for FormID conflicts with other ESPs and ESMs, including Oblivion.esm itself. As such, it remains an interesting property without any practical use ... yet. --Khadir

Okay, but it's 1) pretty obscure, 2) not easy to do, 3) has no advantages, and 4) is probably inherently dangerous -- the sort of tweak that leads to completely obscure and hard to track down crashes. So, I don't think that it's worth including on the article page, where it's basically an unnecessary complication in the explanation of formids. --Wrye 21:11, 19 June 2006 (EDT)

Well, where does it have a place, then? I'd think the FormID page should be a complete reference for what they are and how the engine uses them. Just because you and me don't see any use for this little property, doesn't mean others won't, either - if they have a chance to know about it. --Khadir 03:41, 20 June 2006 (EDT)

First, I'd say that the point of the page is to provide practical information about formids both to users and programmers -- this doesn't fall into that category. Moreover, it's essentially an oversight on the part of the programmers -- it's clearly not supposed to work -- it's just that they didn't put in an error check for it. In general, such bugs should not be documented (which would only encourage their use) -- unless there's some useful exploit associated with them. (E.g., the more than 4 transport destination exploit in Morrowind.) But I see no useful exploit associated with this bug.

In other words, because it's a bug, it shouldn't be added to the page. That argument could be outweighed by some substantial utility associated with the bug, but there isn't any.

Meanwhile, it's here on the discussion page. If some programmers is really dedicated to finding every nook and cranny, they can find it here. --Wrye 10:59, 20 June 2006 (EDT)

[edit] What's a mod?

This is what the article says: "This suggests that Oblivion.esm should always be the first mod to load" <- you can not call the most fundamental master file a "mod"... OMG! What exactly does "mod" mean anyway?!? Is it short for modification or modifier? Or module? Everyone's talking about "mods", except the game developers themselves, which makes it a 100 % unofficial and obscure term. --FMan 19:12, 2 October 2006 (EDT)

Mod = module. In my experience that's the most useful definition.--Wrye 17:44, 3 October 2006 (EDT)