(Image inside) UV offcenter but textures working. Causing issues Blender newbie here.

I'm working with a premade model that's textured, material'd, rigged, the works. I'm attempting to import it into Unity, hence the textures. Unity is not the problem.



As in the example above, all of the UVs are above the textures themselves. (Specifically, they are simply 'slid' up just off the texture-image. Mirroring them would cause them to be backwards)

However, in the 3D viewport when viewed with Textures/Materials/Rendered, the model is perfectly fine.

This is causing Unity to think that the textures aren't working at all. While I could go through and shift all the UVs down, I'm looking to learn and would like to know what the issue is, and if there's a way to quickly fix something like this.

Is it user error on my part? Fault of the person who built the model? Why would the textures still render fine if the UVs are offcenter?

Please and thanks for your help!
The textures render fine because they are "repeated" by default: you can display this behaviour by clicking the relative option in the Properties panel (N) of a UV editor window.

In my example, as the image is 2048x2048, if I select all UV vertices and grab (G) them by 2048 in the Y axis I would get your situation: the render would be exactly the same.

In your case you can read the Y dimension of your texture (let's say 1024 x 1024), select all the UV and press G,Y,-,1,0,2,4,Enter.

The UV will be centered, the render will be the same and Unity will be happier.

I don't know why the modeler did this little mistake.