Weird thin lines after unwrap cube uv mapping It shows a very thin lines at edges after I uv-mapped a cube into a 3x2 grid env-mapping as shown below:




By right it should not show the thin lines and the texture should go smoothly between faces. I also make sure there's no extra spaces between the uv vertices in uv mapping editor by setting the uv vertex into exact x and y position. Why does it still have the thin lines after all these?

Add-on:


I'm using Blender internal GLSL rendering.
After rendering in image, the lines still visible. The lines appear at all edges.
After I export fbx and use it in unity3D, it has the same issue as well.


Source file: skybox.blend
You are running into Blender interpolating your texture a little, so that when it "smoothes" the pixels of the texture, it's grabbing the next texture over and averaging with the local color, creating an off color along your UV edges.  

You can:


Turn off interpolation, but beware, this will make the texture a little more pixely.
Unpack your UV's a little and put an "average color" in the space in between so it interpolates better.  It looks like you baked this texture, you also might want to try just re-baking after doing this.


[Edit]

Downloading and messing with the file showed that interpolation was not the issue here (or at least turning it off doesn't help).  It seems that the UV's overlap so perfectly that the line is an artifact of that.  Fixing it is simple:


Go to the UV editor, press a until all UV's are selected.
Switch pivot type to "Individual Origins"
press s and scale all the uv's down a hair, doesn't take much




Should be fixed after that.