  We introduce a novel approach to calculating three-dimensional freeform
reflectors with a scattering surface. Our method is based on optimal transport
and utilizes a Fredholm integral equation to express scattering. By solving
this integral equation through a process similar to deconvolution, which we
call `unfolding,' we can recover a typical specular design problem.
Consequently, we consider freeform reflector design with a scattering surface
as a two-step process wherein the target distribution is first altered to
account for scattering, and then the resulting specular problem is solved. We
verify our approach using a custom raytracer that implements the surface
scattering model we used to derive the Fredholm integral.
