Abstract: A marking assembly for marking feature locations of a material and an automated processing system that uses input from the marking assembly to process the material. Feature locations such as defect positions and the size of the material are measured with an optical measuring device. The optical measuring device sends and receives light along a light path that is substantially parallel to a processing dimension of the material. A user manually interrupts the light path at a feature location, sending light from the feature location to the optical measuring device. The optical measuring device measures the feature location from the light received from the feature location and sends the feature location to a processor. The processor automatically positions the material relative to a modifying device, based on the feature location.