Introduction
Meshes for Morrowind
A NIF is an object or objects from a 3D scene optimized for the NDL's NetImmerse and Gamebryo game engine. There are different versions Nifs as things evolve, Morrowind uses nif version 4.0.0.2 . MW nifs were originally created in Autodesk/Dicreet's 3D Studio Max and exported by Bethesda's official TESexporter. The exporter was publicly released in 2002.
The TESexporter only works for the specific version of 3DSmax it was compiled for. Bethesda switched versions of max during production of TES3 so there are 2 different builds, max3 and max4. I don't know the specifics but it is my understanding that the max 3 version has some limitations. The max4 exporter also works with max 5, however it crashes when trying to export morph animations. It does export everything else including skeleton and biped animations, physique, and particles.
Freedom Force is a game that also uses nif version 4.0.0.2 Irrational Games released two exporters for Freedom Force, one for 3DSMax 3.1 and one for 3DSMax 4 which also supports 3DSMax 5.
At first 3dsmax was the ONLY way to make meshes for Morrowind, and there were no importers to edit nifs. Modders soon learned to hex edit nifs to change properties and textures. Then Dave Humphrey created a basic nif importer for max and a stand alone nif-to-3ds converter. He also created Niftexture so textures and material settings could easily be edited without the pain of hex-editing.
In 2004 NIFLA, NetImmerse File Format Liberation Association was formed and much of the nif file format was decoded. An alpha importer and exporter was made for Milkshape3D and no longer did modders have to shell out thousands of dollars for very hard to find older versions of max or resort to piracy. Then due to a hard drive crash the source code was lost and development of the milkshape plugin ceased.
NIBLE, short for NetImmerse Block Editor was created with help from NIFLA. Not a 3D modeller but an editor of block settings in the NIF file itself. Many new things that could not be done with niftexture and milkshape were possible, such as glowmaps, transparency, and more.
NIFLA evolved into Niftools and import/export plugins developed for newer versions of 3dsmax, Maya, Gmax, and Blender supporting not only Morrowind but all versions of nif files. These still do not match the export power of the official TESexporter with max4.2.
Niftools also developed Nifskope, much like NIBLE but much more. Things that cannot be imported or exported using the 3D package plugins can be copied and edited with nifskope. It can also import 3DS and OBJ format so meshes can be made with other 3D programs that support those formats.