geom_vase vs geom_faces

code-faces.R

library(readr)
library(dplyr)
library(ggplot2)

faces <- read_csv("faces.csv")

vase <- bind_rows(select(faces, x = x1, y),
                  select(faces, x = x2, y) %>% arrange(y))

faces %>%
  ggplot() +
  geom_polygon(aes(x1, y), fill = "white") +
  geom_polygon(aes(x2, y), fill = "white") +
  geom_polygon(aes(x, y), fill = "black", data = vase)

faces.csv