Rainstorm

https://diode.zone/w/p4pN7zRTSKyrHpWZy58rEV watch on diode zone (has some weird swimming artifacts from transcoding)

https://archive.org/download/mathr-rainstorm/rainstorm-960x540p30.mp4 2.8GB original file download from internet archive (SD; the HD version is 16GB so I didn't upload it)

Hybrid escape time fractal zoom made with WIP renderer using perturbation and bilinear approximation acceleration techniques.

The soundtrack is a processed field recording of raindrops on a window.

Formula: iterations of 3 functions in a loop:

z -> z^2 + c
(x+iy) -> (-x-i|y|)^2 + c
(x+iy) -> (x+i|y|)^2 + c

in a neighbourhood of

c_0 = -0.2398293627569060909198717432381775938509752467470312695251804250084913739345239559183195403014204196268507722888196521855373229301482490542888484011903902461 6257867560430752033277490852847796483351381166394548018933722797 + i 0.6652457321189603881048491220795335001926371976462002306704914404761294177791835520149831679425585170032446633898458839560373228041657973852542633078836579730 86015526458974574219020939914825441528285719869283835245322117397

final zoom factor around 10^210, maximum iteration count 8M, maximum steps per pixel 200k.

Home made software:

  -  fraktaler 3 to render fractal keyframes
  -  zoomasm to assemble video
  -  dr1/long to timestretch audio (inspired by phase vocoder from Pure-data)

Third party software:

  -  ffmpeg with x264 to encode video
  -  fdkaac to encode audio
  -  audacity for audio editing
  -  fftw3, sndfile for time stretcher
  -  gmp, mpfr, mpfrc++/mpreal for arbitrary precision numerics
  -  glm for maths
  -  openexr for image IO
  -  sdl2 and glfw3 for desktop windows
  -  glew for OpenGL
  -  dear imgui and imgui-filebrowser for user interface
  -  miniaudio for audio
  -  tomlplusplus and toml11 for parameter files
  -  gcc compiler

Hardware:

  -  original sound sample recorded with Zoom H4N field recorder (stereo 24bit 96kHz)
  -  desktop AMD Ryzen 7 2700X CPU
  -  graphics AMD Radeon RX 580 GPU (OpenCL for fractal calculations and OpenGL for colouring / GUI)
  -  external USB3 WD hard disk with ~285GB used for temporary data

Linkback: https://fractalforums.org/index.php?topic=4795.0