Source: countdown-with-blob.pov
The Persistence of Vision Ray Tracer, or POV-Ray, is free software that has been around since 1991. The magic of typing a description of something and effectively seeing a photograph of it minutes (OK... sometimes hours) just using maths still seems incredible to me. Of course, a lot has happened in the decades since, with modellers and games engines and GPUs (and now AI seemingly bypassing the whole thing). But I still have a nostalgic affection for POV-Ray and sometimes go back to the old scene description language and play with it just for fun.
I used POV-Ray to produce the images of Planetarium, most obviously in the framing device that presents the hand-drawn artwork (although you can see some in the illustrated solutions too, if you get the end).
The cover of the Fudebakudo book (including its spider) was rendered in POV-Ray, with the bitmap of the cartoon samurai mapped onto a “flat” cut-out in the scene.
There are more examples of my occasional use of POV-Ray in the scrapbook (tagged #povray), as well as the EveryPolitician bot.