Agents of STRIKE
The pinnacle of disguise technology, the Photostatic Veil is a mask of holographic nanofibers worn over the face that can be programmed to create a 3D facsimile of another person.
It is combined with an impression synthesizer worn over the trachea that alters the voice in real time to simulate the person’s speech, allowing for a very accurate simulation at least at passing glance.
The Veil is far from perfect. People who know the subject of the disguise well won’t be fooled, and it won’t hold up to incredibly close scrutiny (such as touch, or extremely close visual inspection). But it’s usually enough to get through a security checkpoint or gain access to a building, and that’s enough for most SHIELD agents.