A system for measuring optical distortion in a contoured glass sheet includes a conveyor for conveying the glass sheet in a first direction, at least one display projecting a preselected multi-phase non-repeating contrasting pattern, and at least one camera, each one of the cameras uniquely paired with one of the displays. The system may also include a control programmed to execute logic for controlling each of the cameras to acquire the desired images, and logic for analyzing and combining the data acquired by the cameras to construct a definition of the surface of the glass sheet, and logicfor performing one or more optical processing operations on the surface data to analyze the optical characteristics of the glass sheet.