Inner Bevel between any (convex) Shape and a Plane In OpenSCAD

thingiverse

An OpenSCAD module creates an inner bevel between a part and a plane at z=h, regardless of the part's orientation to the z-plane. The bevel is h_bevel high and r_bevel wide; equal values result in a circular cross section. The number of faces along the bevel's cross section is fn_bevel (linear for 1). 'Roundness' is given by $fn. Projection and minkowski operations are used, with hull applied to two layers of consecutive height. Ensure convex shapes with no holes or disjoint parts, as these commands have limitations. This module is inspired by GregFrost's Thingiverse design; it lacks documentation/comments.