This is an experiment to generate rounded 3D shapes from 2D shapes by insetting their SDF according to the radius of a sphere. The goal is similar to pillow_medial, but the results do not look nearly as compelling. Also see pillow_sphere. The main difference from pillow_sphere is that we instead use the maximum of the SDF instead of 1, potentially preventing odd behavior for asymmetrical shapes.
Renderings
Here is what happens when you apply the algorithm to a heart shape: