Make render_movie work also in a batch job [FEATURE]

[kondofersky]

Hi,

first: thanks fpr the amazing package. I am rather new to geo plotting and managed to get the hang out of it pretty fast.

In my project, I want to produce potentially hundreds movies of different 3d maps each with a background elevation map and a specific path clipped to it. This works just fine if I do it from an active R session where the rgl window is opened and the movie is produced. However, if I try to trigger this movie creation script externally (e.g. regularly via a cronjob or whenever a new event occurs via Rscript) all I get is a black screen the same length as the supposed movie should have been. I assume that this is probably due to the nonavailable X11 engine and thus the desired frames are missing.

So here is my request/question: is there a way to make a movie with render_movie() without openeing the rgl window? If not, is it possible to implement such a feature?

Thanks a lot!