Machine vision system with a computer generated virtual reference object

A method for measuring an object comprising:

• receiving a three-dimensional computer generated virtual reference object, wherein the received virtual reference object is generated based on a model drawing of the object and the virtual reference object comprises exact coordinates of the object, wherein the exact coordinates comprise coordinates of at least one discrete point;
• acquiring at least two images of the object, wherein the acquired at least two images are acquired with at least two different cameras;
• determining a three-dimensional location of at least one discrete point on the object based on the acquired images, wherein the determined three-dimensional location is in the same coordinate system with the three-dimensional computer generated virtual reference object;
• determining the corresponding discrete point coordinates on the virtual reference object;
• and
• based on the determined location of at least one discrete point on the acquired images and corresponding exact coordinates on the virtual reference object,
• computing the absolute scale location of at least one discrete point on the object.