Patent ID: 7596468

Claim:
A computer-implemented method for measuring a selected portion of a curved surface of an object, the method comprising: (a) displaying a straight-line across an object along an axial vector of an X-axis of a current visual angle; (b) stretching the straight-line to form a plane according to an axial vector of a Z-axis of the current visual angle, and determining a plurality of intersection points between the plane and the curved surface of the object, wherein the curved surface of the object comprises a plurality of point-clouds; (c) determining a vertical point of each point-cloud around the straight-line on the curved surface, a corresponding vertical distance from each of the point-clouds to the curved surface, and a corresponding normal vector of a vertical line from each of the point-clouds to the curved surface; (d) projecting the vertical points onto the plane vertically so as to generate projections of the point-clouds on the plane; (e) determining a plurality of measured points, a plurality of up tolerance points, and a plurality of down tolerance points for each of the plurality of the point-clouds around the straight-line on the plane according to the projections, the corresponding vertical distance, and the corresponding normal vector of the vertical line; (f) connecting each of the measured points so as to generate a measured line, connecting the intersection points between the plane and the curved surface so as to generate an intersection line, connecting each projection and a corresponding measured point of each of the projections so as to generate connected lines, connecting the up tolerance points so as to generate an up tolerance line, and connecting the down tolerance points so as to generate a down tolerance line; and (g) determining if one or more dimensions of a selected portion around the straight-line of the object is acceptable by determining one of if a deviation of the measured line from the intersection line is acceptable, and by determining if each connected line is inside an area between the up tolerance line and the down tolerance line.