The technology causes disappearance of a real object in a field of view of a see-through, mixed reality display device system based on user disappearance criteria. Image data is tracked to the real object in the field of view of the see-through display for implementing an alteration technique on the real object causing its disappearance from the display. A real object may satisfy user disappearance criteria by being associated with subject matter that the user does not wish to see or by not satisfying relevance criteria for a current subject matter of interest to the user. In some embodiments, based on a 3D model of a location of the display device system, an alteration technique may be selected for a real object based on a visibility level associated with the position within the location. Image data for alteration may be prefetched based on a location of the display device system.