What is the difference between Saving 'packages' and 'extracting' ?

[Gildor]

Well, I use these terms: "export", "extract", "save".

Export is probably self-explaining, but I'll add a few words. This word in computer software usually means - get something stored in internal data format, and save that information in a format suitable for other software. For Maya you can export a "mb" scene into fbx file format - it will lose some information, but you can open fbx somewhere else. In umodel e.g. for a skeletal mesh - mesh is stored in some internal UE4 format, I'm loading it into umodel's data structures (can't say "format" because it's in-memory, not a disk representation), then save it to psk or gltf disk format.

"Extract" depends on what you're extracting. This term means no data conversion. Extracting from a pak file means - get some file and save it to disk. I use "save selected packages" in UI for that, just decided to use "save" term for it. In a case of game which is not packaged with a pak file, this will copy data - with no extraction. So "save" word is more suitable here.

Extracting an upk or uasset file - this is done with "package extractor" tool. It loads an uasset ("package") and saves every internal data as a separate file. I use it from time to time to inspect what's stored inside a package, the data is not useful FOR ME in any other way. Some people does something more with extracted data, sometimes they even able to replace some structures by recombining package back from extracted data.

"Saved package" won't be useful for Unreal editor - editor is not designed to work with such kind of data. There are 2 kinds of uassets in UE4 (same for upk in UE3): "source assets" and "cooked assets". Cooked assets contains data for packaged game, source assets doesn't contain "cooked data" but has data useful for editor. A simplest example - texture asset. For "source asset" it contains PNG image, for cooked asset - DDS texture, in a DIFFERENT place. When package is marked internally as "source asset", it often uses different file layout. For a static mesh, uasset contains "raw mesh" - something what was imported from fbx and stored directly into uasset. It doesn't contain optimized data, LODs etc.

Unreal engine (ALL versions) packages has version information to be able to load older package into a newer engine editor. Older Unreal engine versions (1 to 3) were possible to load older cooked packages into an updated game made with newer engine. For some reason, UE4 has stripped that information, so you MUST say to umodel which engine is used for the game. Not sure if I should explain why version data is stripped, just will say that it is called "unversioned package". All versions are filled with zeros in a cooked UE4 game. The game, when it sees unversioned package, just assumes that the package was saved with EXACTLY the same engine version as game has, i.e. they were packaged for it. Editor silently rejects unversioned packages.

So, to be able to load a package saved from a game into UnrealEd, you'll need to restore version information, convert "cooked" data to "source", then probably UnrealEd with pick it up.

This way of storing data makes modding a very difficult thing, unless game provides "source" packages for required things - in game's SDK (e.g. Ark Survival Evolved). Epic did some addition to the engine for UT4 modding (Unreal "Tournament", not "Engine") - but the game was abandoned.

Hopefully I've answered your questions.

[Gildor]

I have been putting off replying to this for like years,. because sometimes you get kind of mad, and I am a very sensitive artist.

Everyone can be sensitive. Not just artist, but a programmer too. So, don't abuse others, covering with "I'm sensitive, I can do that", please

Now, answering to parts which I recognized as questions.

I guess I should just ask again,..
Other than the way I mention in Notepad++  can we use, or interpret or get any goodness of any kind, (ideally actual usefulness)  from the data of the blueprints in cooked .Ussets?

Neither with Notepad, nor in other text or binary editor. Unreal engine using very complex data structures, you can't edit it. Just imagine yourself editing a EXE or DLL file to change the behavior.

is there a concise description anywhere of how to swap out a character mesh?

I didn't see any. May be other people do.

Don't you like Star Trek TNG???!!

Definitely not. I watched new 3 movies (Star Trek reboot), I liked them. Never had a desire to watch older ones.

Do you ever need Unreal Engine Assets?  I have almost every Marketplace Asset there ever was,..     hint hint  (and after 25+ years in Hollywood, millions of assets from music making tools, Kontakt libraries, to Professional Motion Capture.)

No, thanks I'm not an asset collector.