Anyone who grew up during the heyday of the View-Master probably wondered how they made those 3D scenes. Florence Thomas was one of the artists responsible for the stereoscopic images. She would sculpt Disney characters from clay and set them in dioramas, then take photographs from two angles to get the stereo effect.
Thomas produced her first reels for View-Master in 1946 --a series of Fairy Tales and Mother Goose rhymes that are still in circulation. According to one source, Thomas "developed special methods of close-up stereo photography and modeling which is now in common use by major motion picture studios" (John Waldsmith, Stereo Views, 1991). She created scenes of such detail and attractiveness that you feel you could step inside and look around a corner at a complete world.
Link -Thanks, John Kankley!