[robespierre]

Ahem. The beginning of computer generated special effects is two decades earlier than that: the first SIGGRAPH conference was held in 1974.

The use of computer generated imagery in motion pictures begins with the Foonly F1 computer and PFR-80 film recorder at Triple-I, used on the movies "Westworld" (1973), "Futureworld" (1976), "Meteor" (1979), "Looker" (1981), "Tron" (1982), and "Flight of the Navigator" (1986); as well as many television spots for commercials and station IDs.

https://www.youtube.com/embed/ou_UYwt0_d0
https://www.youtube.com/embed/fWxToM_KPeA

I'm sure some film recorders were used in conjunction with IRIS Indigos, but keep in mind the disk space requirements. In 1992, the largest 3.5" SCSI disks (that would fit in an Indigo) were about 1 GB (e.g. Seagate Hawk ST11200N), and the Indigo has 3 internal narrow SCSI bays. 4K imagery, uncompressed, takes up 35 MB per frame, so an Indigo, fully loaded with disks, could only store less than 4 seconds worth of imagery for film output. A larger machine like a 4D/420 or Crimson would have been more capable in that role.