I'm working on a custom mesh for Fallout (Modelling and texturing for Fallout is the same as oblivion, there are more knowledgeable people here)

The lighting on the ceiling is very uneven. Anyone know how to fix it?

http://i721.photobucket.com/albums/ww216/SpeedyB64/LightingProblem.png

It looks like the ceiling is an 'L' shape. If so, hopefully it's 3 coplanar quads or, after triangulation, 6 coplanar tris. If this assumption is true, I would try the following:
1> Select all and remove doubles.
2> With all still selected, scale along the axis perpendicular to the ceiling plane, 0.00001. This makes sure that all faces of the ceiling are, in fact, coplanar.
3> Turn on display of the normals and verify that they are all pointing in the same direction, downward, perpendicular to the plane of the ceiling. Fix, if not.
4> Verify that the UV map is straightforward with no overlaps. If the map of the whole ceiling is much larger than a texture of a single ceiling tile, that's fine.
5> In the .nif file, use the spell Batch > Update All Tangent Spaces.

If not of these fix the problem, maybe you could post the relevant files on MediaFire. I might also be useful if you mentioned what modeling program you are using.

Also make sure your smoothing is set up correctly. Auto-smooth is easiest. There are http://wiki.blender.org/index.php/Doc:Manual/Modeling/Meshes/Smoothing#Smoothing_the_mesh_geometry to show you how.

I do not believe there are any smoothing issues with a flat plane like the ceiling at issue.

The screenshot shows signs of it though?
Can't hurt to make sure he's using auto-smooth anyway.

Here is a screenshot of the ceiling mesh:

http://i721.photobucket.com/albums/ww216/SpeedyB64/Ceiling.png

I use 3ds max.
In nifskope the normals are all straight. All -1 on the Z axis.

Here is the mesh and textures:

http://www.mediafire.com/?rx5m2n73c4csa79

I was thinking it might have something to do with the specular map. But it looks fine to me.

3ds max has autosmooth as well.

The model / mesh looks fine to me so just try using http://www.3dmax-tutorials.com/Smooth_Modifier.html Basically just make sure the faces meant to be "1 piece" are in the same smooth group.

I have tried that. I'll give it another shot though.
I've been working with Max for 6 years so I know the software. I've been modeling for Oblivion and Fallout since shortly after oblivion released. So feel free to get technical.

SpeedyB,

I've fixed it, or at least made it much better. It was a UV mapping issue.

When I loaded your initial mesh into NifSkope, I did not see the shading issue. Usually, shading issues that show in game are visible in NifSkope. So I imported the mesh into Blender and re-exported it as a .nif file. That changed the BSShaderPPLightingProperty and BBShaderTextureSet blocks into the more familiar NiTexturingProperty and NiSourceTexture blocks. Now the weird shading was visible in the NifSkope render. After verifying, as you did, that all the normals were pointing as they should, I suspected a UV map issue. I've found that sometimes you can have overlapping UV maps with no issues, while other times you cannot. I have not discovered all the reasons why this happens in some instances and not others.

So, first I simplified things by eliminating everything but your Object02, the ceiling tile surface. Also, I noticed that your mesh was very far from the object center. Although this should not affect shading, I've found that is can create a big hit to frame rate. So I moved the ceiling surface to the origin. I made a new 512x512 texture of the ceiling tile bottom surface only from your 1024x1024 ModOfficeQuad02 texture. I also saved it in DXT1 rather than DXT5, since there are no transparent parts. I then re-UV mapped it with this ceiling tile only texture, so there would be no overlaps. See the NifSkope renders below.

http://i164.photobucket.com/albums/u28/VinceB_photo/CeilingBefore.png

http://i164.photobucket.com/albums/u28/VinceB_photo/CeilingAfter.png

Good find Vince

I don't currently have blender etc installed so couldn't open it up.

Thanks Vince!
The problem seems to be the UVs on top of eachother.
Thankfully I can keep using my original texture. Fallout usually puts 4 textures per image.