1. A method for determining 3D distances on a 2D pixelized image of a part or object using a camera, a 3D CAD model of the object, and a workstation that includes a display, said method comprising: acquiring a real 2D pixelized image of the object, using the camera; operating the workstation to create a simulated image of the object using the 3D CAD model and the 2D pixelized image; use the workstation to determine a specified cost function comparing the simulated image with the real 2D pixilated image; repositioning the simulated image in accordance with interated adjustments of a relative position between the CAD model and the 2D pixilated image to change the simulated image until the specified cost function is below a specified value; once below the specified value, using the workstation to generate a 3D distance scale matrix using the repositioned simulated image; and using the workstation to measure and display distances between selected pixels on a surface of the real image using 2D distances on the 2D pixelized image of the object and the 3D distance scale matrix.