Also included are techniques for mesh optimization and geometry idealization. An approach to automatic tetrahedral meshing is presented by Li, Teng and Ungor where a combination of ideas from both advancing front and sphere packing methods are used. Karamete, Beall and Shephard also present a method for triangulating arbitrary polyhedra, a problem frequently arising in mesh adaptation and remeshing. Various aspects of the hexahedral meshing problem are extensively covered in this issue. A mesh extrusion technique is first introduced by Vassberg, where an elliptic system, typically used in structured grid generation, is used for generating regular quadrilateral and hexahedral meshes.
Sweeping techniques are an efficient way of generating all-hexahedral meshes within solid models.
With this technique, a mesh is typically swept through the volume from a single source surface to a single target, generating a hexahedral mesh as it is swept. Lai, Benzley and White extend the applicability of sweeping by introducing a method for allowing multiple source and target surfaces. White and Tautges address the issue of automatic recognition of sweepable geometries, providing criteria for when sweeping or other more general algorithms may be applied. When an appropriate mesh generation scheme has been selected, intervals must be assigned to the boundaries before hexahedral meshing methods can proceed. Shepherd, Benzley, and Mitchell introduce an automated technique for assigning appropriate intervals for multiple source and target swept meshes.