Properties of Gauss images. There are certain obvious properties of Gauss images which correspond to visual smoothness: Long edges in the Gauss image correspond to large kink angles between adjacent faces (see Figure 3). Also, the shape of the Gauss image cycle of a vertex (again, see Figure 3) defines the shape of the mesh’s surface in the immediate neighbourhood of a vertex. Therefore, we look for an even pattern of dual faces in the Gauss image.