Extrude Normal

This function returns an object with the surfaces resulting of extruding the input surfaces according to their local normal vectors.

The resulting surfaces are a parallel approximation of the original ones, so in case of you need multiple parallel layers, it is recommended to generate each one from the original surfaces. Take special care in concave regions which may result wrong shapes.

The only required parameter is the extrusion distance that may be positive or negative.

The next figure shows and example of the resulting surfaces when this function is applied to a parabolic reflector.