Methods and apparatus are provided for controlling the temperature of powders in a powder-based additive manufacturing system using spatial light modulation. Powder layer temperatures can be measured and selectively controlled using a radiation source comprising a spatial light modulator. The spatial light modulator applies a visible light radiation and/or IR radiation. In addition to controlling the pre-fused temperature of the powder in the image plane, the spatial light modulator can also apply the radiation to fuse the powder.