Hexahedral shell mesh construction via volumetric polycube map

Abstract

Shells are three-dimensional structures. One dimension, the thickness, is much smaller than the other two dimensions. Shell structures can be widely found in many real-world objects. This paper presents a method to construct a layered hexahedral mesh for shell objects. Given a closed 2-manifold and the user-specified thickness, we construct the shell space using the distance field and then parameterize the shell space to a polycube domain. The volume parameterization induces the hexahedral tessellation in the object shell space. As a result, the constructed mesh is an all-hexahedral mesh in which most of the vertices are regular, i.e., the valence is 6 for interior vertices and 5 for boundary vertices. The mesh also has a layered structure that all layers have exactly the same tessellation. We prove our parameterization is guaranteed to be bijective. As a result, the constructed hexahedral mesh is free of degeneracy, such as self-intersection, flip-over, etc. We also show that the iso-parametric line (in the thickness dimension) is orthogonal to the other two isoparametric lines. We demonstrate the efficacy of our method upon models of various topology.