Decoding TXI commands for texture files?

[OldTimeRadio]

Whenever NWN loads a texture file, it checks to see if there's a corresponding file with the same name as the texture but with the extension TXI. So, if NWN loads up texture.tga or texture.dds, it'll check for texture.txi. A TXI file is in simple plaintext but the commands inside can powefully effect how the image is processed.

A TXI file can contain just one command or dozens of them. In some cases, a TXI for a texture can even reference another texture or textures, and those textures can have TXI files of their own which will also be acted on by the engine. Pretty powerful stuff.

The problem is that, while some things are known (mostly from Bioware examples), after all these years both the NWN and KotOR modding communities are mostly in the dark about:
1. What the full list of commands are that work in a TXI file
2. What type of data is expected when a certain command is used
3. What commands require other commands in order to work

From string dumps of NWMain.exe, there are a huge number of candidates for TXI commands possible but the only way to test them, so far, has been to brute force test and that often either results in A) No noticeable change to the texture or B) a crash.

Without knowing what data the game is expecting/is acceptable in these TXI, one can perform hundreds or even thousands of these brute force tests and get no meaningful results.

Is there something that can be used to help decipher this once and for all? A similar state of affairs exists with ASCII model commands. While many examples of the commands exist from Bioware models there are other commands which, like the TXI commands, remain elusive after a decade.

Thanks!