  Massive stars in binary systems have long been regarded as potential sources
of high-energy gamma rays.The emission is principally thought to arise in the
region where the stellar winds collide and accelerate relativistic particles
which ubsequently emit gamma rays. On the basis of a three-dimensional
distribution function of high-energy particles in the wind collision region -
as obtained by a numerical hydrodynamics and particle transport model - we
present the computation of the three-dimensional nonthermal photon emission for
a given line of sight. Anisotropic inverse Compton emission is modelled using
the target radiation field of both stars. Photons from relativistic
bremsstrahlung and neutral pion decay are computed on the basis of local wind
plasma densities. We also consider photon photon opacity effects due to the
dense radiation fields of the stars. Results are shown for different stellar
separations of a given binary system comprising of a B star and a Wolf-Rayet
star. The influence of orbital orientation with respect to the line of sight is
also studied by using different orbital viewing angles. For the chosen
electron-proton injection ratio of 0.01, we present the ensuing photon emission
in terms of two-dimensional projections maps, spectral energy distributions and
integrated photon flux values in various energy bands. Here, we find a
transition from hadron-dominated to lepton-dominated high-energy emission with
increasing stellar separations. In addition, we confirm findings from previous
analytic modeling that the spectral energy distribution varies significantly
with orbital orientation.
