A method and
system for visualizing deviations on an actual surface 10, 30 from a nominal, or designed, surface 28 utilizes a
system and method for mapping the spatial (e.g. x, y and z) coordinates of the actual surface 10, 30 into a computer 13, comparing the mapped actual surface to the nominal surface 28 to produce a three-dimensional distribution of deviation values (D),
processing this distribution into a topographical pattern 34 of multiple contours or areas 34a . . . 34n, each contour or area having the same, or generally the same, deviation value (D), and optically projecting this topographical pattern 34 onto the actual surface 10, 30 in registry with the initial
surface mapping to provide a display of the surface deviations (D) directly on the actual surface 10, 30. The deviations are measured along a direction D normal to the actual surface so that the three-dimensional distribution is given in x, y, D coordinates. The optical projection is preferably a
laser projection 38. The mapping and projection onto the actual surface 10, 30 are made, and coordinated with one another, with respect to three reference points 32 on the surface 10, 30.