Increase resolution of R rayshader image

I'm trying to make an image using rayshader package. I've been happy that I've been able to create a png file using code like so:

library(ggplot2)
library(rayshader)

example_plot <- 
  ggplot(data.frame(x=c(1,2,3),y=c(4,5,6),z=c(5,4,3)),aes(x=x,y=y,color=z)) + geom_point()

plot_gg(example_plot, width = 2, height = 2, multicore = TRUE, scale = 125, 
        zoom = 0.5, phi = 60, theta=-10, windowsize = c(3200, 3200), offset_edges = TRUE)

Sys.sleep(2.0)

render_depth(focus = 0.5, focallength = 100, fstop = 8, clear = TRUE,filename="example.png")

Unfortunately, I can't figure out how to make the output image be a higher resolution. I've tried adjusting the windowsize which at low values seems to make a difference, but I've hit some sort of ceiling where the resolution of the output image won't go above 1372 x 893. What can I do to get an output image that is around 3200 x 3200 resolution?

Thanks!

Currently, rayshader is limited by rgl's lack of support for device sizes greater than the resolution of the screen. I tested it out on my 1440p monitor, and I was able to get render_snapshot() to create an image 2564x1421 (approximately the resolution of a 1440p monitor). If your monitor supports higher resolutions, you may be able to increase the snapshot size by temporarily increasing your desktop resolution. Otherwise, it's currently a limitation (see this github issue):

https://github.com/tylermorganwall/rayshader/issues/28

However, if you have the time/patience and don't mind the slightly different type of image it produces, render_highquality() uses a completely different rendering engine and can be set to any size output. Just set the width and height arguments to the desired size when calling that function.