rgl::writeWebGL( , prefix = , )

On 03/02/2015 12:18 PM, David Winsemius wrote:

On Feb 3, 2015, at 7:14 AM, Duncan Murdoch wrote:

On 03/02/2015 9:43 AM, Keith.Jewell at campdenbri.co.uk wrote:

Dear all,

I am using writeWebGL to create an HTML page containing an interactive 3D plot. It works fine with the default prefix="" but fails when I specify a prefix "for different scenes displayed on the same web page" (quoting ?writeWebGL).  I'm sure I'm misreading the help, and would appreciate guidance.

Briefly, it works fine with the default writeWebGL( ,prefix="", ) and the template containing %WebGL%
I have not been able to make it work with any other value of prefix; e.g. writeWebGL( ,prefix="A",) and the template containing %AWebGL%

Here is code illustrating the problem.

First create three templates:
a) Vanilla: copied system.file(file.path("WebGL", "template.html"), package="rgl") to file.path(getwd(), "template.html")

b) First attempt: ?writeWebGL says # "[the template] should contain a single line containing paste("%", prefix, "WebGL%"), e.g. %WebGL% with the default empty prefix"
paste("%", "A", "WebGL%")
# [1] "% A WebGL%"
so file.path(getwd(), "templateA.html") is a copy of (a) replacing %WebGL% with % A WebGL%

c) Second attempt: file.path(getwd(), "templateB.html") is  a copy of (a) replacing %WebGL% with %AWebGL%

then, in R
#-----------
library(rgl)
plot3d(1:5, 1:5, 1:5) # generate rgl scene
#-----------
# a) vanilla
writeWebGL(dir=getwd(), template = file.path(getwd(), "template.html"), prefix="")
# works OK; result opens and works in IE
#----------------
# b) First attempt, my reading of ?writeWebGL
writeWebGL(dir=getwd(), template = file.path(getwd(), "templateA.html"), prefix="A")
# Error in writeWebGL(dir = getwd(), template = file.path(getwd(), "templateA.html"),  :
#                       template ?m://templateA.html? does not contain %AWebGL%
# so it looks as if the help is trivially wrong, it should be paste0
paste0("%", "A", "WebGL%")

Yes, that's right.  I'll fix it.

# [1] "%AWebGL%"
#----------------
# c) second attempt using %AWebGL%
writeWebGL(dir=getwd(), template = file.path(getwd(), "templateB.html"), prefix="A")
# runs without error in R but IE displays "You must enable Javascript to view this page properly."
#--------------

I don't understand why (c) is different from (a).

There may be an error in the generated Javascript.  In Firefox, you could ask to see the browser console log, and it would report if there was an error on the page; sometimes those make the Javascript fail, and it falls back to the error message you saw.  I don't know how/if you can do that in IE.

Here are the system details:

R version 3.1.0 (2014-04-10)
Platform: i386-w64-mingw32/i386 (32-bit)

locale:
[1] LC_COLLATE=English_United Kingdom.1252
[2] LC_CTYPE=English_United Kingdom.1252
[3] LC_MONETARY=English_United Kingdom.1252
[4] LC_NUMERIC=C
[5] LC_TIME=English_United Kingdom.1252

attached base packages:
[1] grDevices datasets  splines   graphics  stats     tcltk     utils
 [8] tools     methods   base

other attached packages:
[1] knitr_1.8       animation_2.3   rgl_0.95.1158   CBRIutils_1.0

That's an old version of rgl; current on CRAN is 0.95.1201. <http://cran.r-project.org/src/contrib/rgl_0.95.1201.tar.gz> (CRAN OSX currently has an old binary; I don't recommend that you use it.  I don't know why they haven't updated to the current one.)

I'm not sure why either, but that newer package does fail compilation on both trunks of the Mac platform. I have version 1098 on my OSX 10.7.5 box (and I'm pretty sure that's the one on my Yosemite-equiped laptop. I just tried compiling from source on the Lion platform with the source at CRAN and it fails there, too. (Sometimes I am able to get packages to compile that report errors on CRAN.)

The first error reported from efforts at installing both 1201 and 1208 versions is:

checking for X... libraries , headers
checking for glEnd in -lGL... no
configure: error: missing required library GL

That looks as though it's not finding the OpenGL libraries.  I think the usual way to get them on a Mac is to install XQuartz.  rgl doesn't have to use X11, but it will (e.g. if you run it from RStudio), and it requires the X11 files for compiling.  I haven't experimented a lot with systems that don't have XQuartz installed, but I just saw one yesterday where even the native OpenGL code (what you get when you run rgl within R.app) wouldn't start; after installing XQuartz, it was fixed.

sessionInfo()