18. An article of manufacture comprising a non-transitory program storage medium readable by a computer, the medium tangibly embodying one or more programs of instructions executable by the computer to perform an annotation method for a three-dimensional model, the method comprising: storing in a computer memory a first set of data representative of the three-dimensional model; storing in the computer memory a second set of data representative of an annotation associated with a first spatial location on the three-dimensional model and a first display view; displaying the three-dimensional model and a first graphical representation of the annotation in a display window according to the first display view, the first graphical representation of the annotation being positioned as specified by the first spatial location associated with the annotation; modifying the displaying of the three-dimensional model in the display window to a second display view different from the first display view; removing, in response to modifying the displaying to the second display view, the first graphical representation of the annotation from the display window; and displaying, in the display window in response to modifying the displaying to the second display view and as a substitute for the removed first graphical representation of the annotation, an annotation indicator representative of the annotation, the annotation indicator being visible on the display window independent of any display view of the three-dimensional model.
18. An article of manufacture comprising a non-transitory program storage medium readable by a computer, the medium tangibly embodying one or more programs of instructions executable by the computer to perform an annotation method for a three-dimensional model, the method comprising: storing in a computer memory a first set of data representative of the three-dimensional model; storing in the computer memory a second set of data representative of an annotation associated with a first spatial location on the three-dimensional model and a first display view; displaying the three-dimensional model and a first graphical representation of the annotation in a display window according to the first display view, the first graphical representation of the annotation being positioned as specified by the first spatial location associated with the annotation; modifying the displaying of the three-dimensional model in the display window to a second display view different from the first display view; removing, in response to modifying the displaying to the second display view, the first graphical representation of the annotation from the display window; and displaying, in the display window in response to modifying the displaying to the second display view and as a substitute for the removed first graphical representation of the annotation, an annotation indicator representative of the annotation, the annotation indicator being visible on the display window independent of any display view of the three-dimensional model. 20. The article of manufacture of claim 18 , wherein the first display view and the second display view are each defined by respective first set of view area limitations and second set of view area limitations that restrict which spatial locations along the three-dimensional model are visible therein, the modifying the displaying of the three-dimensional model in the display window resulting in the second spatial location of the annotation indicator being outside the second set of view area limitations, with the annotation indicator being displayed on a periphery of the display window.