J

I thought you meant the UV name. I've actually never created a new lightmap but I have reassigned lightmaps to other existing ones, to balance out the spacing.

The UV defines how the texture is applied. You can see it if you select a mesh and switch to the UV tab. You can name it anything. The first UV is the texture. The second UV is the lightmap

They are just a texture. For a new mesh, you can duplicate the texture UV and turn on lightmap in the KOTOR mesh settings. The game engine blends the vertex shading, diffuse texture and the lightmap together (per pixel).

Yeah it's a process but in most cases you need to rewrap with new UVs. Not only do you need to switch to the secondary UV on every mesh. You have to select each mesh that shares a lightmap and rewrap. Once you do that for every lightmap, you can bake new ones. Plus you have to adjust the light sources and world background color to get it looking right. You could also just edit the lightmap manually with an image editor.

Oh I am very interested in this

When Aspyr upgraded opengl, they had to rewrite the shaders. The new second shader pass overrides the fog coloring for meshes with a lightmap.

I searched Kotor 2 txi's and only the 1 texture used that water effect. The vanilla texture causes frame stuttering and editing that texture causes crashing.

It doesn't do anything. Removing it is fine. The force cage texture is also bugged. Removing the water effect from the TXI fixes it. Then theres a few textures that don't come with a TXI when decompiled and will have alpha issues. Dantooine leaves, korriban blast damage, and a shrub are the ones I remember.

This can be fixed by setting alpha depth to 0.0 when converting with tga2tpc. Click the eye icon next to the texture name You will also find textures missing a TXI with punchthrough parameter, which looks like the issue in the screenshot posted.