  Many white dwarfs host disks of dust produced by disintegrating planetesimals
and revealed by infrared excesses. The disk around G29-38 was the first to be
discovered and is now well-observed, yet we lack a cohesive picture of its
geometry and dust properties. Here we model the G29-38 disk for the first time
using radiative transfer calculations that account for radial and vertical
temperature and optical depth gradients. We arrive at a set of models that can
match the available infrared measurements well, although they overpredict the
width of the 10 $\mu m$ silicate feature. The resulting set of models has a
disk inner edge located at 92-100 $R_\text{WD}$ (where $R_\text{WD}$ is the
white dwarf radius). This is farther from the star than inferred by previous
modeling efforts due to the presence of a directly illuminated front edge to
the disk. The radial width of the disk is narrow ($\leq$10 $R_\text{WD}$); such
a feature could be explained by inefficient spreading or the proximity of the
tidal disruption radius to the sublimation radius. The models have a
half-opening angle of $\geq$1.4$^\circ$. Such structure would be in strong
contradiction with the commonly employed flat-disk model analogous to the rings
of Saturn, and in line with the vertical structure of main-sequence debris
disks. Our results are consistent with the idea that disks are collisionally
active and continuously fed with new material, rather than evolving passively
after the disintegration of a single planetesimal.
