  Dust attenuation varies substantially from galaxy to galaxy and as of yet
cannot be reproduced from first principles in theoretical models. In Nagaraj et
al. (2022), we developed the first Bayesian population model of dust
attenuation as a function of stellar population properties and projected galaxy
shape, built on spectral energy distribution (SED) fits of nearly 30,000
galaxies in the 3D-HST grism survey with broadband photometric coverage from
the rest-frame UV to IR. In this paper, we apply the model to galaxies from the
large-volume cosmological simulation TNG100. We produce a UVJ diagram and
compare it with one obtained in previous work by applying approximate radiative
transfer to the simulated galaxies. We find that the UVJ diagram based on our
empirical model is in better agreement with observations than the previous
effort, especially in the number density of dusty star forming galaxies. We
also construct the intrinsic dust-free UVJ diagram for TNG and 3D-HST galaxies
at z ~ 1, finding qualitative agreement but residual differences at the 10-20%
level. These differences can be largely attributed to the finding that TNG
galaxies have, on average, 29% younger stellar populations and 0.28 dex higher
metallicities than observed galaxies.
