An apparatus for making a three-dimensional object, comprising: a photohardenable material container having an inhibitor-permeable surface that is permeable to a photohardening inhibitor; a build platform movable along a build axis relative to the photohardenable material container; a source of solidification energy operable to project solidification energy images through the inhibitor-permeable surface; at least one controller having a processor and a computer readable memory having instructions stored thereon, wherein when executed by the processor, the instructions cause the controller to carry out a method, the method being characterized in that it comprises: alternating between sets of continuous solidification energy image exposure periods and sets of discontinuous solidification energy image exposure periods, wherein during each set of continuous solidification energy image exposure periods, solidification energy images corresponding to cross- sections of the three-dimensional object are continuously projected onto a surface of the photohardenable material as the build platform continuously moves through a distance along a build axis corresponding to a selected number of object layers, and during each set of discontinuous solidification energy image exposure periods, the build platform discontinuously moves along the build axis, and solidification energy images corresponding to cross-sections of the three-dimensional object are discontinuously projected onto the surface of the photohardenable material only when the build platform is stationary along the build axis to solidify the selected number of object layers. a photohardenable material container having an inhibitor-permeable surface that is permeable to a photohardening inhibitor; a build platform movable along a build axis relative to the photohardenable material container; a source of solidification energy operable to project solidification energy images through the inhibitor-permeable surface; at least one controller having a processor and a computer readable memory having instructions stored thereon, wherein when executed by the processor, the instructions cause the controller to carry out a method, the method being characterized in that it comprises: alternating between sets of continuous solidification energy image exposure periods and sets of discontinuous solidification energy image exposure periods, wherein during each set of continuous solidification energy image exposure periods, solidification energy images corresponding to cross- sections of the three-dimensional object are continuously projected onto a surface of the photohardenable material as the build platform continuously moves through a distance along a build axis corresponding to a selected number of object layers, and during each set of discontinuous solidification energy image exposure periods, the build platform discontinuously moves along the build axis, and solidification energy images corresponding to cross-sections of the three-dimensional object are discontinuously projected onto the surface of the photohardenable material only when the build platform is stationary along the build axis to solidify the selected number of object layers. alternating between sets of continuous solidification energy image exposure periods and sets of discontinuous solidification energy image exposure periods, wherein during each set of continuous solidification energy image exposure periods, solidification energy images corresponding to cross- sections of the three-dimensional object are continuously projected onto a surface of the photohardenable material as the build platform continuously moves through a distance along a build axis corresponding to a selected number of object layers, and during each set of discontinuous solidification energy image exposure periods, the build platform discontinuously moves along the build axis, and solidification energy images corresponding to cross-sections of the three-dimensional object are discontinuously projected onto the surface of the photohardenable material only when the build platform is stationary along the build axis to solidify the selected number of object layers.