# [R] Rgl: rotation and colorbar

Duncan Murdoch murdoch.duncan at gmail.com
Thu Jun 19 18:11:35 CEST 2014

```On 19/06/2014, 1:00 PM, Céline b wrote:
> Hello,
>
> I'm trying to add a colorbar to a 3d map using rgl.
> For this purpose, I draw the map in a similar way of persp3d example :
>
> lat <- matrix(seq(90,-90, len=50)*pi/180, 50, 50, byrow=TRUE)
> long <- matrix(seq(-180, 180, len=50)*pi/180, 50, 50)
>
> r <- 6378.1 # radius of Earth in km
> x <- r*cos(lat)*cos(long)
> y <- r*cos(lat)*sin(long)
> z <- r*sin(lat)
>
> open3d()
> persp3d(x, y, z, col="white",
>        texture=system.file("textures/worldsmall.png",package="rgl"),
>        specular="black", axes=FALSE, box=FALSE, xlab="", ylab="", zlab="",
>        normal_x=x, normal_y=y, normal_z=z)
>
> then I add a basic colorbar drawing several 3d colored cubes and label them using text3d
>
> text3d(x+dx,y+dy,z+dz,"label")
>
> The results is ok (if someone know a better way to do it, please tell me how)
> Now I would like to improve the result and in particular I would like to have a static colorbar (stick to a plan parallel to the window) when I rotate the "earth".
> My first idea is to redefine the rotation button using  rgl.setMouseCallbacks and then pop and redraw colorbar in update fonction of   rgl.setMouseCallback.
> 1/ Is it a good idea ?
> 2/ How to get angle and x,y,z value  to compute rotationMatrix(angle,x,y,z) from window coordinates ?
> 3/ Is it possible, in the same idea,  to have a static colorbar when I zoom on a earth region ?
>
> I hope my question is clear (as you see I am not a  native english speaker) and thank you for your answers.

Unless you are in a real hurry, I wouldn't recommend doing it this way.
I am making some additions to rgl that will make this much easier,
though it is likely a month or so before these reach CRAN.

If you would like to try the changes before release, you can find them
on the rgl page on R-forge:  https://r-forge.r-project.org/projects/rgl/
The new changes are in the "subscenes" branch of the svn tree.  This is
not so easy to use, so if you let me know the platform and R version you
are using, I'd be happy to build you a copy that you can install.

Duncan Murdoch

```