  We report on our extensive photometry and imaging of Comet 46P/Wirtanen
during its 2018/19 apparition and use these data to constrain modeling of
Wirtanen's activity. Narrowband photometry was obtained on nine epochs from
2018 October through 2019 March as well as 10 epochs during the 1991, 1997, and
2008 apparitions. The ensemble photometry reveals a typical composition and a
secular decrease in activity since 1991. Production rates were roughly
symmetric around perihelion for the carbon-bearing species (CN, C$_3$, and
C$_2$), but steeper for OH and NH outbound. Our imaging program emphasized CN,
whose coma morphology and lightcurve yielded rotation periods reported in a
companion paper (Farnham et al., PSJ, 2, 7). Here, we compare the gas and dust
morphology on the 18 nights for which observations of additional species were
obtained. The carbon-bearing species exhibited similar morphology that varied
with rotation. OH and NH had broad, hemispheric brightness enhancements in the
tailward direction that did not change significantly with rotation, which we
attribute to their originating from a substantial icy grain component. We
constructed a Monte Carlo model that replicates the shape, motion, and
brightness distribution of the CN coma throughout the apparition with a single,
self-consistent solution in principal axis rotation. Our model yields a pole
having (R.A., Decl.) = 319$^\circ$, $-$5$^\circ$ (pole obliquity of 70$^\circ$)
and two large sources (radii of 50$^\circ$ and 40$^\circ$) centered at
near-equatorial latitudes and separated in longitude by $\sim$160$^\circ$.
Applications of the model to explain observed behaviors are discussed.
