I would like to set  zoom mouse control in rgl in order to redraw the map with more or less details depending of the zoom coefficient (such as google maps or openstreetmap do).

I already tried the rgl.setMouseCallbacks(button, begin = NULL, update = NULL, end = NULL) function but this function do not seem to work with  trackball (only left, middle and right click).

Thus the question is :is it possible to modify trackball function using rgl ? 
Thank for your help 		 	   		  
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