[R] Using 'polygon' in a 3d plot

[Ted Freeman]

I'm new to R, after many years of using Matlab. I've found the R 
function 'polygon' to be nearly equivalent to the Matlab function 
'patch'. For example, the R commands:

plot(c(0, 5), c(0, 4), type = 'n', asp = 1, ann = FALSE)
x <- c(1, 2, 2, 1.5, 1)
z <- c(1, 1, 2, 1.7, 2)
polygon(x, z, col = 'green')

produce a plot with a small green shape exactly as I expect. A nearly 
identical plot can be made in Matlab with these commands:

x = [1, 2, 2, 1.5, 1];
z = [1, 1, 2, 1.7, 2];
patch(x, z, 'g')
axis([0, 5, 0, 4])
box on

In Matlab I am able to extend this quite easily to a three-dimensional 
plot by simply adding one more vector argument to 'patch'. I don't see 
how to do this in R using 'polygon'. (I've primarily looked at 
scatterplot3d.) Is there another function I can use?

Since I expect that many of you do not use Matlab, I've put two 
graphics showing the example above (Plot 1) and a similar 
three-dimensional plot (Plot 2) on this page:
http://staff.washington.edu/freeman/patch.html.

It's Plot 2 that I'd like to be able to reproduce in R.

Thanks for any advice!

  -- Ted