NOTE: The film is silent, but still great.
This film explains how the computer scientists and mathematicians at Bell Labs created early computer graphics films, like most (though not all) of these films, made by Bell Labs employees E.E. Zajac, A. Michael Noll, Ken Knowlton, Frank Sinden, and many others.
A Computer Technique..., from 1964, gives the basics on the process, from Ken Knowlton's BEFLIX programming language for a raster-scan (bitmap) output, to the hardware details (IBM 7094 mainframe, Stromberg-Carlson 4020 microfilm printer).
Footage Courtesy of AT&T Archives and History Center, Warren, NJ