1 .. _basic_meshing_algos_page:
3 ************************
4 Basic meshing algorithms
5 ************************
7 The MESH module contains a set of meshing algorithms, which are used for meshing entities (1D, 2D, 3D sub-shapes) composing geometrical objects.
9 An algorithm represents either an implementation of a certain meshing technique or an interface to the whole meshing program generating elements of several dimensions.
16 * For meshing of 1D entities (**edges**):
17 * **Wire Discretization** meshing algorithm - splits an edge into a number of mesh segments following an 1D hypothesis.
18 * **Composite Side Discretization** algorithm - allows to apply a 1D hypothesis to a whole side of a geometrical face even if it is composed of several edges provided that they form C1 curve in all faces of the main shape.
19 * For meshing of 2D entities (**faces**):
22 * **Triangle: Mefisto** meshing algorithm - splits faces into triangular elements.
23 * :ref:`quad_ijk_algo_page` meshing algorithm - splits faces into quadrangular elements.
25 .. image:: ../images/image123.gif
29 "Example of a triangular 2D mesh"
31 .. image:: ../images/image124.gif
35 "Example of a quadrangular 2D mesh"
37 * For meshing of 3D entities (**solid objects**):
40 * **Hexahedron (i,j,k)** meshing algorithm - solids are split into hexahedral elements thus forming a structured 3D mesh. The algorithm requires that 2D mesh generated on a solid could be considered as a mesh of a box, i.e. there should be eight nodes shared by three quadrangles and the rest nodes should be shared by four quadrangles.
41 .. image:: ../images/hexa_ijk_mesh.png
45 "Structured mesh generated by Hexahedron (i,j,k) on a solid bound by 16 faces"
48 * :ref:`cartesian_algo_page` meshing algorithm - solids are split into hexahedral elements forming a Cartesian grid; polyhedra and other types of elements are generated where the geometrical boundary intersects Cartesian cells.
49 .. image:: ../images/image125.gif
53 "Example of a tetrahedral 3D mesh"
55 .. image:: ../images/image126.gif
59 "Example of a hexahedral 3D mesh"
62 Some 3D meshing algorithms, such as Hexahedron(i,j,k) also can
63 generate 3D meshes from 2D meshes, working without geometrical
66 There is also a number of more specific algorithms:
68 * :ref:`prism_3d_algo_page` - for meshing prismatic 3D shapes with hexahedra and prisms.
69 * :ref:`quad_from_ma_algo_page` - for quadrangle meshing of faces with sinuous borders and rings.
70 * **Polygon per Face** meshing algorithm - generates one mesh face (either a triangle, a quadrangle or a polygon) per a geometrical face using all nodes from the face boundary.
71 * :ref:`projection_algos_page` - for meshing by projection of another mesh.
72 * :ref:`import_algos_page` - for meshing by importing elements from another mesh.
73 * :ref:`radial_prism_algo_page` - for meshing 3D geometrical objects with cavities with hexahedra and prisms.
74 * :ref:`radial_quadrangle_1D2D_algo_page` - for quadrangle meshing of disks and parts of disks.
75 * :ref:`use_existing_page` - to create a 1D or a 2D mesh in a python script.
76 * :ref:`segments_around_vertex_algo_page` - for defining the length of mesh segments around certain vertices.
79 :ref:`constructing_meshes_page` page describes in detail how to apply meshing algorithms.
81 **See Also** a sample TUI Script of a :ref:`tui_defining_meshing_algos` operation.
92 use_existing_algos.rst
94 radial_quadrangle_1D2D_algo.rst
95 define_mesh_by_script.rst
96 segments_around_vertex_algo.rst