Hex Me If You Can

Abstract

HEXME consists of tetrahedral meshes with tagged features, and of a workflow to generate them. The main purpose of HEXME meshes is to enable consistent and fair evaluation of hexahedral meshing algorithms and related techniques. The tetrahedral meshes have been generated with Gmsh, starting from 63 computer-aided design (CAD) models coming from various databases. To highlight and label the various and challenging aspects of hexahedral mesh generation, the CAD models are classified into three categories: simple, nasty and industrial. For each CAD model, we provide three kinds of tetrahedral meshes. The mesh generation yielding those 189 tetrahedral meshes is defined thanks to Snakemake, a modern workflow management system, which allows us to define a fully automated, extensible and sustainable workflow. It is possible to download the whole dataset or to pick some meshes by browsing the online catalog. Since there is no doubt that the hexahedral meshing techniques are going to progress, the HEXME dataset is also built with evolution in mind. A public GitHub repository hosts the HEXME workflow, in which external contributions and future releases are possible and encouraged.

Hex-Mesh Generation and Processing: a Survey

“…Whether it is for their (uncertain) superiority or because of the presence of highly trusted legacy code that runs only on hexahedral grids, the interest for hexahedral meshes is still high both in industry and in academia. This is witnessed by the growing number of scientific articles published in recent years [Beaufort et al 2021], by the central role that hexahedral grids occupy in industrial and commercial software, and ultimately by the interest that the industry manifests for each advancement in hex-mesh generation.…”

“…The Hexalab project [Bracci et al 2019] collects output data from the most prominent mesh generation methods in the literature, but it is not meant to be a validation database for novel methods. A few contributions in this direction have been proposed very recently: [Ledoux 2021;Reberol et al 2019] propose input CAD models, while [Beaufort et al 2021] offers input tetrahedral meshes with tagged feature entities. Specifically, hard constraints on the preservation of feature curves and (boundary and interior) surfaces can be very challenging for meshing algorithms.…”

“…4. This includes in particular sets of example hexahedral meshes generated by these various methods, but also hex-dominant meshes (e.g., [Gao et al 2017b]) as well as challenging input models (e.g., [Beaufort et al 2021;Ledoux 2021;Reberol et al 2019]). The HexaLab project [Bracci et al 2019] is a unified portal to visualize hexahedral meshes directly in a web browser as well as to download them.…”