I'm a programmer trying to put an image texture on the face of my character model. I used the mirror modifier to model my character. When I UV unwrap the face the image is mirroring on both sides of the face. When I turn the mirror modifier off, I can only see half of the body of my character. Can anyone guide me on how to turn this mirror texture stuff off?
You can't have custom texture coordinates for both sides of a mirrored object, since they - as well as the geometry are created by the modifier.
You can however choose how to mirror the UV islands in the modifier's settings, using the checkboxes for flip U and flip V. They should about get you there.
If you need to apply completely idependent UVs, you will have to apply the modifier. If you want to texture paint, and issues with the modifier arise, you can safely duplicate your object, apply the modifier on the copy and paint on that one, deleting it once you're done.