Medial axis tree—an internal supporting structure for 3D printing

Abstract

Saving material and improving strength are two important but conflicting requirements in 3D printing. We propose a novel method for designing the internal supporting frame structures of 3D objects based on their medial axis such that the objects are fabricated with minimal amount of material but can still withstand specified external load. Our method is inspired by the observation that the medial axis, being the skeleton of an object, serves as a natural backbone structure of the object to improve its resistance to external loads. A hexagon-dominant framework beneath the boundary surface is constructed and a set of tree-like branching bars are designed to connect this framework to the medial axis. The internal supporting structure is further optimized to minimize the material cost subject to strength constraints. Models fabricated with our method are intended to withstand external loads from various directions, other than just from a particular direction as considered in some other existing methods. Experimental results show that our method is capable of processing various kinds of input models and producing stronger and lighter 3D printed objects than those produced with other existing methods.