I have a rectangular block (Dielectric Resonator ANtenna) and I would like to round the corners for easy 3D printing.
It will be hard for me to create the round corners from the beginning as the creation of this shape starts in Matlab and there are some limitations.
Is there a direct way to round all sharp corners after creating the rectangular block? I know how to construct these corners from scratch but NOT modifying the rectangle to have round corners.

Thanks in advance.