  We have developed a multidimensional radiation hydrodynamics code to simulate
the interaction of radial stellar pulsation and convection for full amplitude
pulsating models. Convection is computed using large eddy simulations. Here we
perform three-dimensional simulations of RR Lyrae stars for comparison with
previously reported two-dimensional simulations. We find that the time
dependent behavior of the peak convective flux on pulsation phase is very
similar in both the two-dimensional and three-dimensional calculations. The
growth rates of the pulsation in the two-dimensional calculations are about
$0.1\%$ higher than in the three-dimensional calculations.The amplitude of the
light curve for a 6500 K RR Lyrae model is essentially the same for our 2D and
3D calculations, as is the rising light curve. There are differences in slope
at various times during falling light.
