Hi all, I am doing a visualization application and I am picking some data on the surface of IDLgrPolygon defined spheres. The procedure which indludes widgets is taken from surf_track.pro. The point is that if I place myself "inside" one of those spheres (I am thinking about a Celestial Sphere), seemingly I am not able to pick "interior" points of the sphere, since they are not recognized. I cannot think about any particular solution at this time. It has come to my mind that as I lose the sphere from the IDLgrView that I am using the object does not appear any more and that´s the reason why I can´t pick the interior points, it it is like this I would like to know how to "force" IDLgrView to keep my object in the "memory" or the "window". Thanks for your time