A data reading system and method for constructing a three-dimensional model of an item passing through a read zone of the data reading system, the system including a plurality of light transmitters each operable to generate a light curtain across the read zone. As the items interrupt each of the light curtains, a height measurement of the item is obtained. Thereafter, the data reading system combines the height measurement data from each of the light curtains taken at various times, and generates a three-dimensional model of the item based on the obtained data.