Diagram summarizing the procedures for generating star-forming galaxies at ﹩z\lesssim 4﹩. ﹩{M}_{\star }﹩ is defined as ﹩\mathrm{log}(M/{M}_{\odot })﹩. High-mass galaxies (defined as ﹩{M}_{\star }\gt 8﹩ for z < 2.4 and ﹩{M}_{\star }\gt 6.3+0.7z﹩ for ﹩z\geqslant 2.4;﹩ illustrated by the left pathway) and low-mass galaxies (right pathway) are generated differently as indicated. These criteria are defined in Section 3.4.4 as the approximate mass completeness limits in the 3D-HST catalog, which we use to assign real galaxy SEDs to high-mass mock galaxies. Gray boxes indicate the empirical relationships, distributions, or data on which mock galaxy properties are based, and colored boxes indicate the mock galaxy property generated in that step. Quiescent galaxies are generated at z < 4 following a different procedure, which is described in Section 4 and illustrated in Figure 13.