R: Export 3D scatterplots non-interactively - r

Question

Creating 3D plots in R opens up an interactive window where the user can rotate the view. For example below using package rgl:
library(rgl)
plot3d(iris[,1:3],col=c("red","green","blue")[iris$Species],size=5)
Is there some way to set a predefined view and export the plot as a regular image. I would like to do this in an automated non-interactive manner for many datasets.

Answer 1

Use scatterplot3d package.
library(scatterplot3d)
graphics.off()
png(filename = "test.png", width = 8, height = 6, units = "in", res = 300)
par(mai = c(0.5, 0.5, 0.5, 0.5))
scatterplot3d(x = iris$Sepal.Length, y = iris$Sepal.Width, z = iris$Petal.Length,
color = c("red","green","blue")[iris$Species],
cex.symbols = 1, pch = 19, angle = -30)
dev.off()

Answer 2

Besides #d.b's answer using scatterplot3d instead of rgl, you could save results using R Markdown. The advantage of doing it this way is that you get an interactive display instead of a static one; the disadvantage is that the format is HTML, not PNG or another bitmap format.
Before knitting the document, run code like this and interactively choose
the initial display you want:
library(rgl)
options(rgl.useNULL = FALSE)
plot3d(iris[,1:3],col=c("red","green","blue")[iris$Species],size=5)
Once you have it oriented correctly, run this code:
M <- par3d("userMatrix")
dput(M)
You'll get something like
structure(c(0.776694416999817, 0.198224693536758, -0.597873568534851,
0, -0.629868388175964, 0.249577552080154, -0.735511302947998,
0, 0.00341932475566864, 0.947849154472351, 0.318700969219208,
0, 0, 0, 0, 1), .Dim = c(4L, 4L))
as output. Then start your R Markdown document with something like
library(rgl)
options(rgl.useNULL = TRUE)
M <- structure(c(0.776694416999817, 0.198224693536758, -0.597873568534851,
0, -0.629868388175964, 0.249577552080154, -0.735511302947998,
0, 0.00341932475566864, 0.947849154472351, 0.318700969219208,
0, 0, 0, 0, 1), .Dim = c(4L, 4L))
(which you would probably choose not to echo), and in each code chunk that produces a plot, write code like this:
plot3d(iris[,1:3],col=c("red","green","blue")[iris$Species],size=5)
par3d(userMatrix = M)
rglwidget()
(If this is in a loop or isn't at the top level for some other reason, you'll need print(rglwidget()) instead.)
Then all of your plots will initially have the same orientation, but all of them will be user-rotatable.