Animate ggplot snowflakes

snowflake.R

library(tidyverse)
library(tweenr)
library(magick)
m <- 2e2
min_s <- 4
k <- 2e2/(min_s)

img <- image_graph(600, 600, res = 96)

plot_snowflakes <- function(data){
 p <- ggplot(data, aes(x,y, size=size))+
    geom_point(color="white", pch=42)+
    scale_size_identity()+
    coord_cartesian(c(0,1), c(0,1))+
    theme_void()+
    theme(panel.background = element_rect(fill = "black"),
          plot.background = element_rect(fill = "black"))
 print(p)
}

merge(
  tibble(t = seq(k)),
  tibble(id = seq(m), d = runif(m),
         x = runif(m), y = runif(m)*5,
         size = runif(m, min=min_s, max=5*min_s))) %>% 
  mutate(y = y - t * size / 2e2,
         x = jitter(x),
         ease = 'linear') %>% 
  tween_elements(time="t", group = "id", 
               ease="ease",
               nframes = 2e2) %>% 
  filter(y>=0, t<k) %>% 
  group_by(.frame) %>% 
  nest() %>% pull(data) %>% 
  walk(.f=plot_snowflakes)

dev.off()
animation <- image_animate(img, fps = 25)
#print(animation)
image_write(animation, "snowflake.gif")