[Art]

The cameras in some Robotic Vacuum cleaners like the Neat-O series use a spinning laser that actually maps the dimension of the room it happens to be in using a technique called LIDAR (LIght Detection A Ranging) enabling it to "construct" a pretty accurate image of its 3D surroundings.

There are programs that are able to "average" or predict the other or hidden sides or areas of an object so a lot of this could be done via a single camera but from different perspectives or angles.

Notice that many movie houses use a single camera shot from one angle then another and from another or perhaps a small room filled with differently mounted cameras in order for them to produce a 3D image representation of the person.

3D goggles/glasses usually require both eyes to experience the illusion. Close one eye and see if the perception or illusion of 3D is still there.

Seems that we can't always believe our eyes and maybe we shouldn't.