In at least 3 vanilla meshes, the bounding spheres of the bones are out of alignment with the corresponding part of the TriShape, making them become invisible when viewed from certain angles.
I made this mod where I manually adjsuted these bounds:
https://www.nexusmods.com/fallout4/mods/70817
It fixes these meshes:
furniture\workstations\workbenchweapons\WorkbenchWeaponsA.nif
furniture\workstations\workbenchweapons\WorkbenchWeaponsB.nif
setdressing\trashbin\TrashBin01.nif
I give you permission to include these meshes with UFO4P as is.
Otherwise, here is how to do it:
- in NifSkope, find the TriShape in question
- expand it, expand it's BSSkin::Instance, select the BSSskin::BoneData. This should make the bone bounding spheres visible.
- The BoneData's BoneList list (NifSkope uses confusing naming here) corresponds to the Bones section of the BSSkin::Instance, that is, first entry is the first bone, etc.
- In each BoneList entry, there is a BoundingSphere entry. This is what needs to be positioned so that the bone's vertices are within it.