  The electromagnetic transients accompanying compact binary mergers
($\gamma$-ray bursts, afterglows and 'macronovae') are crucial to pinpoint the
sky location of gravitational wave sources. Macronovae are caused by the
radioactivity from freshly synthesised heavy elements, e.g. from dynamic ejecta
and various types of winds. We study macronova signatures by using
multi-dimensional radiative transfer calculations. We employ the radiative
transfer code SuperNu and state-of-the-art LTE opacities for a few
representative elements from the wind and dynamical ejecta (Cr, Pd, Se, Te, Br,
Zr, Sm, Ce, Nd, U) to calculate synthetic light curves and spectra for a range
of ejecta morphologies. The radioactive power of the resulting macronova is
calculated with the detailed input of decay products. We assess the detection
prospects for our most complex models, based on the portion of viewing angles
that are sufficiently bright, at different cosmological redshifts ($z$). The
brighter emission from the wind is unobscured by the lanthanides (or actinides)
in some of the models, permitting non-zero detection probabilities for
redshifts up to $z=0.07$. We also find the nuclear mass model and the resulting
radioactive heating rate are crucial for the detectability. While for the most
pessimistic heating rate (from the FRDM model) no reasonable increase in the
ejecta mass or velocity, or wind mass or velocity, can possibly make the light
curves agree with the observed nIR excess after GRB130603B, a more optimistic
heating rate (from the Duflo-Zuker model) leads to good agreement. We conclude
that future reliable macronova observations would constrain nuclear heating
rates, and consequently help constrain nuclear mass models.
