Graphics Reference
In-Depth Information
Animating a Three-Dimensional Plot
Problem
You want to animate a three-dimensional plot by moving the viewpoint around the plot.
Solution
Rotating a 3D plot can provide a more complete view of the data. To animate a 3D plot, use
play3d()
with
spin3d()
:
library(rgl)
plot3d(mtcars$wt, mtcars$disp, mtcars$mpg, type
=
"s"
, size
=
0.75
, lit
=
FALSE
FALSE
)
play3d(spin3d())
Discussion
By default, the graph will be rotated on the z (vertical) axis, until you send a
break
command to
R.
You can change the rotation axis, rotation speed, and duration:
# Spin on x-axis, at 4 rpm, for 20 seconds
play3d(spin3d(axis
=
c(
1
,
0
,
0
), rpm
=
4
), duration
=
20
)
To save the movie, use the
movie3d()
function in the same way as
play3d()
. It will generate a
series of .pngiles, one for each frame, and then attempt to combine them into a single animated
.gifile using the
convert
program from the ImageMagick image utility.
This will spin the plot once in 15 seconds, at 50 frames per second:
# Spin on z axis, at 4 rpm, for 15 seconds
movie3d(spin3d(axis
=
c(
0
,
0
,
1
), rpm
=
4
), duration
=
15
, fps
=
50
)
The output file will be saved in a temporary directory, and the name will be printed on the R
console.
If you don't want to use ImageMagick to convert the output to a .gif, you can specify
conver-
t=FALSE
and then convert the series of .pngiles to a movie using some other utility.
