[R] Question about contour3d and writeWebGL: rgl and misc3d package

[Duncan Murdoch]

On 12-11-16 5:59 PM, John Muschelli wrote:
> I saw that in rgl:::writeWebGL that "Polygons will only be rendered as
> filled; there is no support in WebGL for wireframe or point rendering.".  I
> found that you can easily use contour3d to make reproducible contour web
> figures, such as (taken from contour3d help)
>
>    library(AnalyzeFMRI)
>
>    a <- f.read.analyze.volume(system.file("example.img", package=
> "AnalyzeFMRI"))
>
>    a <- a[,,,1]
>
>    contour3d(a, 1:64, 1:64, 1.5*(1:21), lev=c(3000),
>
>              alpha = c(0.2), color = c("white"))
>
> browseURL(paste("file://", writeWebGL(dir=file.path(tempdir(), "webGL"),
>
>            width=500), sep=""))
>
> But I found problems with multiple levels, such as
>
>    contour3d(a, 1:64, 1:64, 1.5*(1:21), lev=c(3000, 8000, 10000),
>
>              alpha = c(0.2, 0.5, 1), color = c("white", "red", "green"))
>
>
> browseURL(paste("file://", writeWebGL(dir=file.path(tempdir(), "webGL"),
>
>            width=500), sep=""))
>
>
> Does anyone know why this happens, or a way to fix it (maybe using separate
> = TRUE for contour3d)?

Why what happens?

Duncan Murdoch