  We examine closely the solar Center-to-Limb variation of continua and lines
and compare observations with predictions from both a 3-D hydrodynamic
simulation of the solar surface (provided by M. Asplund and collaborators) and
1-D model atmospheres. Intensities from the 3-D time series are derived by
means of the new synthesis code ASSET, which overcomes limitations of
previously available codes by including a consistent treatment of scattering
and allowing for arbitrarily complex line and continuum opacities. In the
continuum, we find very similar discrepancies between synthesis and observation
for both types of model atmospheres. This is in contrast to previous studies
that used a ``horizontally'' and time averaged representation of the 3-D model
and found a significantly larger disagreement with observations. The presence
of temperature and velocity fields in the 3-D simulation provides a significant
advantage when it comes to reproduce solar spectral line shapes. Nonetheless, a
comparison of observed and synthetic equivalent widths reveals that the 3-D
model also predicts more uniform abundances as a function of position angle on
the disk. We conclude that the 3-D simulation provides not only a more
realistic description of the gas dynamics, but, despite its simplified
treatment of the radiation transport, it also predicts reasonably well the
observed Center-to-Limb variation, which is indicative of a thermal structure
free from significant systematic errors.
