This Film is Extraordinary and although you can generate such work on a standard PC these days, back in the 1980’s, it was the cutting edge of CGI. It was rendered on a battalion of Apollo Computers, one single frame at a time.
100 systems linked together were used working tirelessly around the clock. The MCP (Master Control Program) would be fed a particular frame to render and then another when that one was finished.
The Entire concept, Ray Tracing and Networking was completely new and innovative and bears notability, given that it took Herculean efforts to see that the system operated smoothly and without error…
Sadly I can’t find ‘rain’ but I remember it on early SunOS systems - late 80’s or so… It used ASCII animation to display what might have looked like raindrops falling into a puddle making expanding circles…
I managed to get an animated GIF.
I searched for converters ASCII (anim) to GIF (anim) but there are only converters the other way. Maybe some JAVA codes but I want it easy.
I then made a video screen grabbing online (screencapture.com). Kdenlive couldn’t handle webm vids so I converted it online to AVI. Then I cropped it with Kdenlive. Exporting as GIF was poor, some black lines turned yellow. (Too thin/256 color issue?)
So I converted it online (ezgif.com)