  A three-dimensional Monte Carlo code for modelling radiation transport in
Type Ia supernovae is described. In addition to tracking Monte Carlo quanta to
follow the emission, scattering and deposition of radiative energy, a scheme
involving volume-based Monte Carlo estimators is used to allow properties of
the emergent radiation field to be extracted for specific viewing angles in a
multi-dimensional structure. This eliminates the need to compute spectra or
light curves by angular binning of emergent quanta. The code is applied to two
test problems to illustrate consequences of multi-dimensional structure on the
modelling of light curves. First, elliptical models are used to quantify how
large scale asphericity can introduce angular dependence to light curves.
Secondly, a model which incorporates complex structural inhomogeneity, as
predicted by modern explosion models, is used to investigate how such structure
may affect light curve properties.
