[R] convert command not found in movie3d (rgl package) in Mac OS X

[Manabu Sakamoto]

Dear list,

I gave up trying to fix my movie3d (rgl library) issue in my PC
(completely black gif/png file) and went ahead and installed MacPorts
and ImageMagick onto my iMac (OSX ver 10.6.8). I think ImageMagick is
successfully installed in its default location (under /opt/local), and
I ran movie3d but I get the following error:

Error in system("convert --version", intern = TRUE) :
  error in running command
sh: convert: command not found

so I'm guessing R can't find the "convert" executable file, which is
in "/opt/local/bin", in its system search path, which I presume is
"/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin" that I got using
Sys.getenv("PATH").

Does anyone know how I can resolve this? For instance, should I move
or copy the convert executable file to an appropriate directory (which
I don't really know where exactly, i.e. I can't find a folder "usr" in
the Macintosh HD), or can I add "/opt/local/bin" to the R's search
path?

best regards,
Manabu

-- 
Manabu Sakamoto, PhD
School of Earth Sciences
University of Bristol
manabu.sakamoto at gmail.com