An example system includes: (i) a resin container defining a cavity; (ii) a plurality of rods extending from an inner base surface of the resin container and into the cavity; (iii) a plurality of light sources arranged to emit radiation into the plurality of rods, such that when the cavity contains liquid resin, radiation passing through a given one of the rods cures liquid resin that surrounds the given rod; and (iv) a control system configured to: (a) receive data specifying a three-dimensional structure; (b) determine a shape for a layer of a plurality of layers that collectively form the three-dimensional structure; and (c) determine one or more of the light sources that correspond to the shape of the layer; and (d) form the layer by operating the one or more determined light sources that correspond to the shape of the layer.