One possibility, which Dave has alluded to, is that you have a second surface placed a small distance above the one you have textured with the carpet. When the camera is beyond a certain distance, the lower one may “bleed” through and be completely visible, whereas when closer it will be hidden. See for example, this topic for some further discussion:
There are also other possibilities, but based on an image we can only guess. If at all possible, please upload the skp so we can take a look.