Abstract: An additive manufacturing system includes one or more light sources and one or more light valves that can be written with two-dimensional gray scale patterns that the light valves impose on beams from the one or more light sources to obtain one or more patterned beams. The one or more patterned beams are steered to each area of a plurality of areas on a layer of powder. The two-dimensional gray scale patterns are selected to achieve desired material properties at each pixel position of the patterned beam incident on the layer of powder. The light valves may modulate one or more of amplitude, phase, or coherence. The material properties may include one or more of Young's modulus, porosity, grain size, and crystalline microstructure.