Abstract: Methods and apparatus for forming a three-dimensional article in which a powdered medium is distributed in a powder bed, heated to a temperature below its melting point, and fused by means of a laser beam projected in the form of an image of a cross section of the three-dimensional article. The image of the cross-sectional layer is created by spatial light modulation of the laser beam using an LCoS display. During the fabrication process, characteristics of the image of the cross-sectional layer are controlled through monitoring of the projection of a holographic representation of the image using one or more imaging devices.