Current radiosity methods rely on the calculation of geometric factors, known as form-factors which describe energy exchange between the surfaces of an environment. The most widely used method for storing the illumination across a surface is a mesh of quadrilaterals and/or triangles. For more exact computations these meshes need to be subdivided adaptively. The subdivision methods create artifacts which have visible results. A new technique for storing the surface is presented, based on Voronoi diagrams, which are well suited for the task, and can be subdivided without introducing artifacts.