  This manuscript will unify inverse freeform reflector design and surface
light scattering to design freeform reflectors with a scattering surface. We
use microfacets, which are small, tilted mirrors superimposed on a smooth
surface. We form a simple model of surface roughness and light scattering based
on the orientations of the microfacets. Using a least-squares solver to compute
the smooth reflector as a starting point, we can subsequently alter the surface
using an optimization procedure to account for the scattering. After
optimization, the resulting reflector surface produces the desired scattered
light distribution. We verify the resulting reflector using raytracing.
