Changing text size of 3d plot, R - r

Question

I have a problem changing the text size of a 3d plot I generated with the package rgl. Everything works fine, but I can't effectively change the cex and size properties of an 3d object when rendering it in shiny, with the renderWebGL
library(rgl)
plot3d(x, y, z, xlab ="x", ylab ="y", zlab ="z")
texts3d(x, y, z, rownames(data))
Any help is highly appreciated! Best Regards.
Brecht

Answer 1

You can scale the text (including axis labels) by changing the "cex" rgl parameter, by calling the function par3d. The "cex" rgl parameter is different from the "cex" parameter in base graphics.
For example, if you want to magnify the text in your plot by a factor of 2, then you can call:
par3d(cex=2.0)
with(iris,
plot3d(Sepal.Length, Sepal.Width, Petal.Length,
type="s", col=as.numeric(Species)))
Note that calling par3d opens a plotting window. Calling a plotting function creates a plot in that same window. You have to call par3d every time you create a new plot. The function par3d can also change many other rgl parameters.

Answer 2

I ran into similar problems with library plot functions from PerformanceAnalytics. I would advise to get the code for the function by typing plot3d in the console and looking at the original plot functions inside.
It might be the case that the plot3d function doesn't pass a cex option forward, so you can also copy the function and modify it to make it your own myplot3d function or something like that.

Answer 3

For anyone still trying to address this issue, the plot3D package takes care of this nicely now.
See the following reproducible code.
# Load plot3D package
library(plot3D)
Using the iris dataset, let's make a 3D graph. See our use of cex, cex.main, and cex.lab at the end, which allow us to multiply text size, all within the package.
scatter3D(
x = iris$Sepal.Length,
y = iris$Sepal.Width,
z = iris$Petal.Length,
# Add a nice background
bty = "u",
col.grid = "darkgrey",
col.panel = "black",
# Specify Labels
main = "My graph",
clab = "Petal\nLength",
xlab = "\nSepal Length",
ylab = "\nSepal Width",
zlab = "\nPetal Length",
# Adjust label sizing
cex = 2, # Multiply dot size by 2
cex.main = 2, # Multiply the size of main title text by 2
cex.lab = 2) # Multiply size of axis label text by 2
Or, we can shrink the text size back to normal, here:
scatter3D(
x = iris$Sepal.Length,
y = iris$Sepal.Width,
z = iris$Petal.Length,
# Add a nice background
bty = "u",
col.grid = "darkgrey",
col.panel = "black",
# Specify Labels
main = "My graph",
clab = "Petal\nLength",
xlab = "\nSepal Length",
ylab = "\nSepal Width",
zlab = "\nPetal Length",
# Adjust label sizing
cex = 1, # Multiply dot size by 2
cex.main = 1, # Multiply the size of main title text by 2
cex.lab = 1) # Multiply size of axis label text by 2

Answer 4

Not the OP situation but if you need to change the text size on a rgl plot and your text is a LaTeX expression you have to pass the text size parameter (cex) to the corresponding function.
For example,
library(rgl)
library(magrittr)
iris %>%
{points3d('x'=.$Sepal.Length, 'y'=.$Sepal.Width, z=.$Petal.Length)}
title3d(main=NULL, sub=setName,
xlab=latex2exp::TeX(r"($\phi_{\pi})"),
ylab=latex2exp::TeX(r"($\phi_{X}$)"),
zlab=latex2exp::TeX(r"($\psi_{B}$)"),
cex=4)
Notice the cex argument in title3d() which is passed to plotmath3d() which actually draws the LaTeX expression into a PNG file that is then paste on the final plot. See the documentation for plotmath3d for details but cex is a number that scales the text size.