Ribbed support vaults for 3D printing of hollowed objects
                        Thibault Tricard, Frédéric Claux, Sylvain Lefebvre
                        Computer Graphics Forum
                        HAL 
                        DOI
                     
                    
                 
                
                
                    
                        
Abstract
                        Additive manufacturing techniques form an object by accumulating layers of material on top of one another. Each layer has to be
                          supported by the one below for the fabrication process to succeed. To reduce print time and material usage, especially in the
                          context of prototyping, it is often desirable to fabricate hollow objects. This exacerbates the requirement of support between
                          consecutive layers: standard hollowing produces surfaces in overhang that cannot be directly fabricated anymore. Therefore,
                          these surfaces require internal support structures. These are similar to external supports for overhangs, with the key difference
                          that internal supports remain invisible within the object after fabrication.
                          A fundamental challenge is to generate structures that provide a dense support while using little material. In this paper, we
                          propose a novel type of support inspired by rib structures. Our approach guarantees that any point in a layer is supported by
                          a point below, within a given threshold distance. Despite providing strong guarantees for printability, our supports remain
                          lightweight and reliable to print.
                          We propose a greedy support generation algorithm that creates compact hierarchies of rib-like walls. The walls are progressively
                          eroded away and straightened, eventually merging with the interior object walls. We demonstrate our technique on a variety of
                          models and provide performance figures in the context of Fused Filament Fabrication (FFF) 3D printing.