Mostly for internal use, this function temporarily installs a handler on a button of the mouse that will return the mouse coordinates of one click and drag rectangle.
rgl.select(button = c("left", "middle", "right"))Which button to use?
A vector of four coordinates: the X and Y coordinates of the start and end of the dragged rectangle.
rgl.select3d, a version that allows the selection region to be used to
select points in the scene.