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112 lines
4.3 KiB
Plaintext
112 lines
4.3 KiB
Plaintext
/*!
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\page a2d_meshing_hypo_page 2D Meshing Hypotheses
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<br>
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<ul>
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<li>\ref max_element_area_anchor "Max Element Area"</li>
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<li>\ref length_from_edges_anchor "Length from Edges"</li>
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<li>\ref hypo_quad_params_anchor "Quadrangle parameters"</li>
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</ul>
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<br>
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\anchor max_element_area_anchor
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<h2>Max Element Area</h2>
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<b>Max Element Area</b> hypothesis is applied for meshing of faces
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composing your geometrical object. Definition of this hypothesis
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consists of setting the <b>maximum area</b> of mesh elements,
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which will compose the mesh of these faces.
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\image html a-maxelarea.png
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\n
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\image html max_el_area.png "In this example, Max. element area is very small compared to the 1D hypothesis"
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<b>See Also</b> a sample TUI Script of a
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\ref tui_max_element_area "Maximum Element Area" hypothesis
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operation.
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<br>
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\anchor length_from_edges_anchor
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<h2>Length from Edges</h2>
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<b>Length from edges</b> hypothesis builds 2D mesh elements having a
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maximum linear size calculated as an average segment length for a wire
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of a given face.
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<b>See Also</b> a sample TUI Script of a
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\ref tui_length_from_edges "Length from Edges" hypothesis operation.
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<br>
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\anchor hypo_quad_params_anchor
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<h2>Quadrangle parameters</h2>
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\image html hypo_quad_params_dialog.png "Quadrangle parameters creation/edition dialog"
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<b>Quadrangle parameters</b> is a hypothesis for Quadrangle (Mapping).
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<b>Base vertex</b> parameter allows using Quadrangle (Mapping)
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algorithm for meshing of trilateral faces. In this case it is
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necessary to select the vertex, which will be used as the fourth edge
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(degenerated).
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\image html hypo_quad_params_1.png "A face built from 3 edges"
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\image html hypo_quad_params_res.png "The resulting mesh"
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This parameter can be also used to mesh a segment of a circular face.
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Please, consider that there is a limitation on the selection of the
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vertex for the faces built with the angle > 180 degrees (see the picture).
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\image html hypo_quad_params_2.png "3/4 of a circular face"
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In this case, selection of a wrong vertex for the <b>Base vertex</b>
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parameter will generate a wrong mesh. The picture below
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shows the good (left) and the bad (right) results of meshing.
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\image html hypo_quad_params_res_2.png "The resulting meshes"
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<b>Type</b> parameter is used on faces with a different number of
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segments on opposite sides to define the algorithm of transition
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between them. The following types are available:
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<ul>
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<li><b>Standard</b> is the default case, when both triangles and quadrangles
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are possible in the transition area along the finer meshed sides.</li>
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<li><b>Triangle preference</b> forces building only triangles in the
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transition area along the finer meshed sides.
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<i>This type corresponds to <b>Triangle Preference</b> additional
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hypothesis, which is obsolete now.</i></li>
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<li><b>Quadrangle preference</b> forces building only quadrangles in the
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transition area along the finer meshed sides. This hypothesis has a
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restriction: the total quantity of segments on all
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four sides of the face must be even (divisible by 2).</li>
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<i>This type corresponds to <b>Quadrangle Preference</b>
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additional hypothesis, which is obsolete now.</i></li>
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<li><b>Quadrangle preference (reversed)</b> works in the same way and
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with the same restriction as <b>Quadrangle preference</b>, but
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the transition area is located along the coarser meshed sides.</li>
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<li><b>Reduced</b> type forces building only quadrangles and the transition
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between the sides is made gradually, layer by layer. This type has
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a limitation on the number of segments: one pair of opposite sides must have
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the same number of segments, the other pair must have an even difference
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between the numbers of segments on the sides. In addition, number
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of rows of faces between sides with different discretization
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should be enough for the transition. At the fastest transition
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pattern, tree segments become one (see the image below), hence
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the least number of face rows needed to reduce from Nmax segments
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to Nmin segments is log<sub>3</sub>( Nmax / Nmin ). The number of
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face rows is equal to number of segments on each of equally
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discretized sides.
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\image html reduce_three_to_one.png "The fastest transition pattern: 3 to 1"
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</li>
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</ul>
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<b>See Also</b> a sample TUI Script of a
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\ref tui_quadrangle_parameters "Quadrangle Parameters" hypothesis.
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<br>
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*/
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