# Form-finding : Modelling Implications
Proceed in the same way as for a non-linear static analysis except that the elements can have Form-finding Properties assigned as well as, or instead of, their true physical properties. The solver looks for the appropriate form-finding property for each element, and if none is defined it uses the normal property. Therefore the model can include a mixture of stiff “real” elements and form-finding elements.
Spacer elements are used to control the mesh (nodal spacing) in soap-film form-finding analysis. These elements are ignored in all the other analysis options.