Translations:Curves GordonSurface/13/en

In this example, the surface on the left, the rails were drawn from +Y to -Y and the resulting surface normal is +Z On the right, the ribs are drawn from -Y to +Y, resulting in the surface normal oriented -Z.
 * The curves of each group (ribs and rails) should touch all curves of the other group.
 * In other words, they must form a grid or net pattern as shown here:
 * In general, the surface normal of the resulting Gordon surface will be determined by the direction of the ribs.