We consider 7 forces applied at the vertices of a convex polygon and we use the algorithm proposed at the end of Section 3 to determine the maximal regions in which an obstacle can be placed so that a strut net avoiding it exists. The movie starts with a picture of the open strut net function on the left-hand side, and the associated open strut net on the right-hand side. Secondly, the cleaving plane passing through the points L1(x1), L2(x2), and L3(x3) is depicted on the lefthand panel, and the corresponding region Γ is depicted in black in the right-hand panel. Pivoting around point L1(x1), the cleaving plane rolls about the line connecting L1(x1) and the last point touched by the plane (initially L3(x3)), spanning over the maximal elements Γ.