Large out-of-core tetrahedral meshing

Abstract

We present an effective strongly uncoupled method, which, given a closed and watertight surface mesh, generates its Delaunay constrained tetrahedri-sation into sub-domains. Uncoupled means here that once chosen, a sub-domain interface will not be changed anymore. This method aims at preserving in the final tetrahedral mesh the properties of the mesh which would have been produced by the original sequential algorithm, namely the constrained input surface mesh and the quality and properties of the volume mesh. To achieve these objectives, our method reorders internal vertices insertion (applying the sequential constrained Delaunay kernel) such that the data can then be fully decoupled in sub-domains without introducing more constraints. Moreover, the interfaces are carefully chosen such that the load is roughly the same in all parts, and such that the interfaces separating the sub-domains are "invisible" in the final mesh. Successfully applied to out-of-core large scale mesh generation, this method allowed us to generate in double precision a 210 million tet mesh on a 4GB core memory single processor machine, and a 680 million tet mesh for a very complex geometry.