15. A non-transitory computer-readable data storage medium comprising instructions causing a computer to: generate a three-dimensional (3D) model of a real-world object; simultaneously display on a computer screen the 3D model and the real-world object in a real-world environment; align the displayed 3D model and the displayed real-world object on the computer screen; reduce the visibility of geometric entities of the displayed 3D model causing the 3D model to appear fully or partially transparent; and display a computer-generated annotation wherein the annotation annotates the 3D model and appears on the displayed real-world object due to the reduced visibility of the 3D model geometric entities.
15. A non-transitory computer-readable data storage medium comprising instructions causing a computer to: generate a three-dimensional (3D) model of a real-world object; simultaneously display on a computer screen the 3D model and the real-world object in a real-world environment; align the displayed 3D model and the displayed real-world object on the computer screen; reduce the visibility of geometric entities of the displayed 3D model causing the 3D model to appear fully or partially transparent; and display a computer-generated annotation wherein the annotation annotates the 3D model and appears on the displayed real-world object due to the reduced visibility of the 3D model geometric entities. 16. The computer-readable data storage medium of claim 15 further comprising instructions to causing a computer to: enable a user to select the displayed real-world object at a location; and reference geometry of the 3D model corresponding to the selected location on the real-world object.