tutorials.md

Tutorials

On this page you will find the description of some of the main features of HexBox.

Refinement

Global Refinement

Global refinement allows you to split each hexahedron in the mesh with a 2-refinement schema (each hexahedron is split into 8 new hexahedra) to increase the whole mesh resolution. To apply this feature, select one hexahedron and press the key combination Ctrl+0. For more details, see Section 3.1.1 in the paper.

Local Refinement

Local refinement allows you to change the resolution only in selected hexahedra, with 3-refinement schemes (each hexahedron is split into 27 new hexahedra). To apply this feature, select the desired hexahedra by using Ctrl+MouseLeft and press the key H. For more details, see Section 3.1.1 in the paper.

Face Refinement

Face refinement allows you to locally edit the singular structure of the mesh, splitting a hexahedron into 6 sub-elements so as to decompose the selected face into 5 quads, 1 central and 4 lateral. To apply this feature, select one face and press the key F. For more details, see Section 3.1.1 in the paper.

Make Conforming

Local refinement and face refinement introduce hanging nodes, producing a non-conforming mesh. We provide the "makeConforming" functionality to restore conformity on the mesh. To apply this feature, press the key Q. For more details, see Section 3.1.1 in the paper.

Extrusion

Single Face Extrusion

The extrusion of a single face can be achieved by selecting one face and pressing the key E. This operation results in a new hexahedron adjacent to the selected face. For more details, see Section 3.1.2 in the paper.

Extrusion of two adjacent faces in a convex configuration

Extruding two adjacent faces in a convex configuration (meaning with a dihedral angle between them > $\pi$) results in two new hexahedra, each of them adjacent to one of the selected faces. This result can be obtained by selecting two faces in a convex configuration by using Ctrl+MouseLeft and then by pressing the key E. For more details, see Section 3.1.2 in the paper.

Extrusion of two adjacent faces in a concave configuration

Extruding two adjacent faces in a concave configuration (meaning with a dihedral angle between them < $\pi$) results in a single new hexahedron adjacent to both selected faces. This result can be obtained by selecting two faces in a concave configuration by using Ctrl+MouseLeft and then by pressing the key E. For more details, see Section 3.1.2 in the paper.

Extrusion of three adjacent faces in a convex configuration

Extruding three adjacent faces in a convex configuration results in three new hexahedra, each of them adjacent to one of the selected faces. This result can be obtained by selecting three faces in a convex configuration by using Ctrl+MouseLeft and then by pressing the key E. For more details, see Section 3.1.2 in the paper.

Extrusion of three adjacent faces in a concave configuration

Extruding three adjacent faces in a concave configuration results in a single new hexahedron adjacent to all the selected faces. This result can be obtained by selecting three faces in a concave configuration by using Ctrl+MouseLeft and then by pressing the key E. For more details, see Section 3.1.2 in the paper.

Extrusion of n adjacent faces in the plane

Extruding N adjacent faces in an almost flat region will generate N new elements adjacent to each other and each of them adjacent to a selected face. This result can be obtained by selecting N adjacent faces by using Ctrl+MouseLeft and then by pressing the key E. For more details, see Section 3.1.2 in the paper.