kisonecat/square-cross-section

A 3-dimensional scene containing an object built from square cross sections

Square Cross Sections

The file scene.pov is a POVray scene which shows off a region built from

{ (x,y) \in R^2 : x+1 <= y <= 3-x^2 }

with square cross sections.

Running povray on scene.ini produces a bunch of PNGs that can be ffmpeged together into a loopable movie:

To generate an .mp4, I used

ffmpeg -framerate 30 -i scene%03d.png -c:v libx264 -r 30 -pix_fmt yuv420p out.mp4                                                                                                                   1 ↵

To generate a animated .gif, I used

ffmpeg -i out.mp4 -vf fps=10,scale=320:-1:flags=lanczos,palettegen palette.png                                                                                                                      1 ↵
ffmpeg  -i out.mp4 -i palette.png -filter_complex "fps=10,scale=320:-1:flags=lanczos[x];[x][1:v]paletteuse" output.gif