The Polynomial Boundary feature () can be added from the model tree under Component using the Shape Optimization context menu. The selection has to be adjacent to a Free Shape Domain, but the Polynomial Shell feature does not have this requirement. In 3D, the feature is only applicable to triangular and quadrilateral boundaries. The Polynomial Boundary feature includes the following settings:

This section is only visible when the polynomial Type is set to Bernstein. In order for the settings to have an effect, the Order has to be larger than 1. The first two settings are only available in 2D.

When the Preserve continuity of normals at symmetry boundaries is Enabled, the normal vector will be fixed at points between the Polynomial Shell feature and the Symmetry/Roller feature.

Similarly, when the Preserve continuity of normals between polynomial boundaries is Enabled, no kinks will be introduced on points between different Polynomial Boundary features, assuming that the boundaries are initially joined continuously. This also applies to points that are internal to the selection of the Polynomial Boundary.

Finally, when the Preserve angles at fixed boundaries is Enabled, no kinks will be introduced on points (or edges in 3D) between Polynomial Boundary and Fixed Boundary features, assuming that the boundaries are initially joined continuously.

See the documentation for the Coordinate System settings of the Free Shape Boundary feature.

See the documentation for the Coordinate System settings of the Free Shape Boundary feature.

Choose the type of polynomial from the Type list: Bernstein (the default) or Lagrange. Then enter an Order n for the polynomial (default: 2).

Bernstein polynomials satisfy the maximum displacement bound everywhere, while Lagrange polynomials only satisfy it in the interpolation points and therefore Bernstein polynomials can be more robust.