The form-finding calculation is performed by displacing the mesh geometry using the Updated Reference Strategy (URS) method. This method generates the equilibrium shapes that comply almost exactly with the specified form-finding boundary conditions (sag, force, and prestress).
The integral approach of the URS considers regular forces, such as self-weight or pneumatic pressure, and thus allows for the calculation of anticlastic and synclastic shapes with planar or rotationally symmetric geometry. In fact, there are two methods available for selection: the tension method for planar shapes, and the projection method for conical shapes with horizontal restraints.