Thanks! For animations I wrote some custom rendering code, with a simple API that exposes a canvas and the ability to paint either constant pixels, which never change in colour, or dynamic pixels that can fade out with time. Then each frame I would simply paint the pixels at the search frontier and the rendering code would take care of the fading out when exporting. Also used the Lab colour space for colour blending.
The rest of the pipeline was straightforward. I exported individual frames in a .ppm format, which was easiest to program, and then stitched them into an .apng animation using ffmpeg. Did quite a few tests initially to choose between .apng and .webp and back then .apng was least glitchy across the devices I have.
