Building Direction Fields on the Medial Object to Generate 3D Domain Decompositions for Hexahedral Meshing

In this work, a novel method for creating decompositions of general 3D domains, suitable for hexahedral mesh generation is presented. To accomplish this, frames and cross-fields are generated on top of the medial object of the domain. The geometrical and topological information carried by the medial object, together with the directional information of the frames/crosses help analyze the domain. By generating frames and cross fields on medial vertices, edges and faces based on touching vectors, a directional field is constructed on top of the medial object. Based on it, critical lines in the domain called, singularity lines, are identified. Starting from these, a complete line network is created on the interior of the domain. This network is extruded to the boundary in order to create the boundary of high-quality partitioning surfaces that are used to decompose the domain into regions appropriate for a high-quality hexahedral mesh. Examples are given to validate the method.