I found this: http://www.psychodogstudios.net/forums/archive/index.php?t-5076.html
Causes of invisible meshes:
- false/ incomplete weightpainting
- flipped normals
- scaling of NiTriShapes in NIFskope: only scale in Blender! (That's why it's better to use a hole body as pattern.)
- .dds without mipmaps, damaged or in false folder
- _n.dds damaged, without mipmaps or false path (there should be only ONE _ in the path)
- only one bone in .nif (to be visible there must be 2 or more bones in the .nif)
- exported NiTriShapes have to be upgraded to .nif file version 20.0.0.5 via transplanting in an existing game .nif
- false/ incomplete weightpainting
- flipped normals
- scaling of NiTriShapes in NIFskope: only scale in Blender! (That's why it's better to use a hole body as pattern.)
- .dds without mipmaps, damaged or in false folder
- _n.dds damaged, without mipmaps or false path (there should be only ONE _ in the path)
- only one bone in .nif (to be visible there must be 2 or more bones in the .nif)
- exported NiTriShapes have to be upgraded to .nif file version 20.0.0.5 via transplanting in an existing game .nif
Which is great information if it's a complete list of what could cause it- I also found this and firmly believe I've narrowed it down after trying the same textures on a different armor, which consequently turned invisible.
http://www.gamesas.com/index.php?/topic/1081703-invisible-bodies-missing-meshes/page__p__15756202__hl__invisible%20armor__fromsearch__1entry15756202
Remember that invisible meshes aren't usually missing meshes. It's more likely that the texture for the mesh is missing its normal map, or the mesh was saved without bone weights (which makes it collapse to a point in-game). There are probably a few other ways for it to exist and not show.
I was gonna try "working" textures on my custom armor to rule out the mesh or .nif problem but If it ends up being my textures I wouldn't know how to fix it- I followed a certain guide I can't find right now that teaches you how to texture a cube, I used photoshop and the nvidia .dds tools to make it, I made the normals too but I have no idea what I did wrong.
Also, I have tried one texture at a time on a "working" piece and that armor turned invisible.(Think I mentioned that already.)
Anyone who'd like to take a quick crack at this with me would have my sincerest thanks.
Edit: Also this, http://www.gamesas.com/index.php?/topic/1077714-a-few-nit-picky-graphic-fixes/page__p__15706985__hl__invisible%20armor__fromsearch__1entry15706985
Invisible armor parts indicates a bad or missing normal map. If it's missing, reinstalling the mod that provides it will fix that. If it's bad, it may not have the proper amount of mipmaps and whoever generated the texture needs to correct that.
Oh and I did use nifscope spells like in this: http://www.tesnexus.com/articles/article.php?id=363
Clean the NIF by running through the Optimize and Sanitize Spells:
Spells --> Optimize --> Remove Bogus Nodes
Spells --> Sanitize --> Adjust Link Arrays
Spells --> Sanitize --> Adjust Texture Sources
Spells --> Sanitize --> Reorder Blocks
Spells --> Sanitize --> Check Links
File --> Save As - Overwrite existing NIF file.
Spells --> Optimize --> Remove Bogus Nodes
Spells --> Sanitize --> Adjust Link Arrays
Spells --> Sanitize --> Adjust Texture Sources
Spells --> Sanitize --> Reorder Blocks
Spells --> Sanitize --> Check Links
File --> Save As - Overwrite existing NIF file.