An Offsetting Framework of Triangular Models for 3D Printing

An efficient and intersection-free model offsetting framework is introduced in this paper to generate shell models for 3D printing. The basic concept of the framework is to offset vertices of the input mesh to obtain an approximate discrete signed distance field for reconstructing the offsetting mesh. The framework first offsets vertices of the mesh by a given distance along their normal directly. These vertices are then adjusted or discarded according to the given offsetting distance to form an approximate discrete signed distance field using a binary space partition (BSP) tree. These reserved vertices are finally reconstructed using Poisson reconstruction algorithms to form the inner surface of the shell model. Results of the framework are intersection and non-manifold free for an arbitrary distance. It also allows different parts of a model for different offsetting distances from user interactions. Several examples are given to demonstrate that the framework is effective and robust for 3D printing.