I don't think the article generalizes trivially to 3D, though.
The solution presented relies on signed distance fields, yet skims over the important part - a distance to what? In 2D it is obvious, we are measuring distance to an edge between the object and its background, to a silhouette.
In 3D, when objects may rotate producing self-occlusions, things get more complicated - what are we measuring the SDF against? The silhouette of a 3D object's 2D projection is ever-changing and cannot be trivially precomputed.