Do the .Nif tools designed for Oblivion/Fallout work for Skyrim or should I be looking for something else?

They won't work right now, but we're working on it.

tk, does Niflib get updated with changes to the XML files? I know that it's not being actively supported, but I'm also not really clear on the whole Python generation thing works: does that update Niflib for new NIF versions? I hope to port NifSE to Skyrim at some point.

I haven't the foggiest, sorry. Amorilia would be a better person to ask.

Fair enough. I'll wait until I'm in a position to actually do the port before bothering him again, though.

An ARES port someday DragoonWraith

I'm no expert, but here it goes: Niflib uses PyFFI, which supports a whole range of a binary formats. Each format is described in an XML file. Adding/updating an XML file should be enough to support a new/updated format.

That was my thinking too, I was hoping to confirm it. But since amorilia's already busy enough and I won't be using it any time soon, that can wait.

I'd certainly like to; we'll see how much from ARES that I can re-use. ARES depends on a lot of decoding of Oblivion, that'll have to be redone for Skyrim. It could be a while.

The file-structure is defined in XML-files. A script converts that into C++ class-bodies and adds some pre-defined getter/setter class-functions. If it finds an existing class-body it preserves marked custom functions of that. So you can manipulate niflib and still regenerate from the newest XML. Nifskope has a dynamic XML-to-API bridge, so you can upgrade Nifskope mostly by just throwing the XML in.
Niflib has nothing to with python or PyFFI besides the XML-file, which is a lot and not at the same time, sort of.

What Ethatron says is dead on. As long as Bethesda didn't do anything like what happened when strings were changed it should be relatively easy to port once the XML file is in a state capable of reading the nif files. Given that they seem still be using Gamebryo 2.2 for the for most nifs I've seen the only thing that is new is probably new objects of the bhk or bs variety. Niflib will be relatively easy to update after the major decoding work is completed.

Ethatron, nothing so drastic this time around. A big area of interest is BSLightingShadingProperty, which is much different than the Fallout 3 versions of a similar block. I'm currently decoding bhkCompressedMeshShapeData, which seems to be all-new, and a bit of a toughie.

My thread isn't really being used, so I should mention again that I can't run the game, so all my initial decodes have no context.

Look into the Havok SDK:

/// This shape is a shape container for triangle soups optimized for efficient memory storage.
/// Triangles are stored in chunks using both triangle strips and lists.
/// It also supports convex pieces and transformed instances (including scaling).
/// For building an hkpCompressedMeshShape from input geometries look at hkpCompressedMeshShapeBuilder.

Oh, I didn't even think of that, thanks!