  We investigate the structural properties of cluster and group galaxies by
studying the Fornax main cluster and the infalling Fornax A group, exploring
the effects of galaxy preprocessing in this showcase example. Additionally, we
compare the structural complexity of Fornax galaxies to those in the Virgo
cluster and in the field. Our sample consists of 582 galaxies from the Fornax
main cluster and Fornax A group. We quantified the light distributions of each
galaxy based on a combination of aperture photometry, S\'ersic+PSF (point
spread function) and multi-component decompositions, and non-parametric
measures of morphology (Concentration $C$; Asymmetry $A$, Clumpiness $S$; Gini
$G$; second order moment of light $M_{20}$), and structural complexity based on
multi-component decompositions. These quantities were then compared between the
Fornax main cluster and Fornax A group. The structural complexity of Fornax
galaxies were also compared to those in Virgo and in the field. Overall, we
find significant differences in the distributions of quantities derived from
S\'ersic profiles ($g'-r'$, $r'-i'$, $R_e$, and $\bar{\mu}_{e,r'}$), and
non-parametric indices ($A$ and $S$) between the Fornax main cluster and Fornax
A group. Moreover, we find significant cluster-centric trends with $r'-i'$,
$R_e$, and $\bar{\mu}_{e,r'}$, as well as $A$, $S$, $G$, and $M_{20}$ for
galaxies in the Fornax main cluster. We find the structural complexity of
galaxies increases as a function of the absolute $r'$-band magnitude (and
stellar mass), with the largest change occurring between -14 mag $\lesssim
M_{r'}\lesssim$ -19 mag. This same trend was observed for galaxies in the Virgo
cluster and in the field, which suggests that the formation or maintenance of
morphological structures (e.g. bulges, bar) is largely dependent on the stellar
mass of the galaxies, rather than their environment.
