The line there is a mipmapping issue. NWN roughly uses what's often called trilinear filtering, where as part of the process to make things in the distance look nicer, a lower res version of the texture is used in the distance. From the looks of it, that's causing the detail from one side of the texture to overlap and affect the other side, as the lower resolution means the pixels are less accurate to your UVs (if that makes sense).
Probably the best solution is to always have a few pixels spare at the edges of textures. A retroactive solution is to drag your UVs away from the edge of the texture a little, possibly modifying the texture a bit so this doesn't create any negative effects.
Modifié par _six, 12 mars 2012 - 07:25 .