X-Git-Url: http://git.salome-platform.org/gitweb/?p=modules%2Fsmesh.git;a=blobdiff_plain;f=doc%2Fsalome%2Fgui%2FSMESH%2Finput%2F2d_meshing_hypo.doc;h=2005ad8d772a7d3eda088acb8697f46d5f2d023f;hp=d72e4d50459e39613ca3ac0bca641acd810f497a;hb=dd0d39d752a4d5ba58ed2e417651093764bb8d09;hpb=bd4e115a78b52e3fbc016e5e30bb0e19b2a9e7d6 diff --git a/doc/salome/gui/SMESH/input/2d_meshing_hypo.doc b/doc/salome/gui/SMESH/input/2d_meshing_hypo.doc index d72e4d504..2005ad8d7 100644 --- a/doc/salome/gui/SMESH/input/2d_meshing_hypo.doc +++ b/doc/salome/gui/SMESH/input/2d_meshing_hypo.doc @@ -2,22 +2,17 @@ \page a2d_meshing_hypo_page 2D Meshing Hypotheses -
- +- \ref max_element_area_anchor "Max Element Area" +- \ref length_from_edges_anchor "Length from Edges" +- \ref hypo_quad_params_anchor "Quadrangle parameters" -
\anchor max_element_area_anchor

Max Element Area

-Max Element Area hypothesis is applied for meshing of 2D faces +Max Element Area hypothesis is applied for meshing of faces composing your geometrical object. Definition of this hypothesis -consists of setting the maximum area of meshing elements (depending on -the chosen meshing algorithm it can be triangles or quadrangles), -which will compose the mesh of these 2D faces. +consists of setting the maximum area of mesh faces, +which will compose the mesh of these faces. \image html a-maxelarea.png @@ -26,31 +21,66 @@ which will compose the mesh of these 2D faces. \image html max_el_area.png "In this example, Max. element area is very small compared to the 1D hypothesis" See Also a sample TUI Script of a -\ref tui_max_element_area "Maximum Element Area" hypothesis -operation. +\ref tui_max_element_area "Maximum Element Area" hypothesis operation. -
\anchor length_from_edges_anchor

Length from Edges

-Length from edges hypothesis builds 2D mesh segments having a -length calculated as an average edge length for a given wire. +Length from edges hypothesis defines the maximum linear size of +mesh faces as an average length of mesh edges approximating +the meshed face boundary. See Also a sample TUI Script of a \ref tui_length_from_edges "Length from Edges" hypothesis operation. -
\anchor hypo_quad_params_anchor

Quadrangle parameters

-\image html hypo_quad_params_dialog.png "Quadrangle parameters creation/edition dialog" - -Quadrangle parameters is a hypothesis for Quadrangle (Mapping). - -Base vertex parameter allows using Quadrangle (Mapping) -algorithm for meshing of triangular faces. In this case it is -necessary to select the vertex, which will be used as the fourth edge -(degenerated). +\image html hypo_quad_params_dialog.png "Quadrangle parameters: Transition" + +Quadrangle parameters is a hypothesis for \ref quad_ijk_algo_page. + +Transition tab is used to define the algorithm of transition +between opposite sides of the face with a different number of +segments on them. The following types of transition +algorithms are available: + +- Standard is the default case, when both triangles and quadrangles + are possible in the transition area along the finer meshed sides. +- Triangle preference forces building only triangles in the + transition area along the finer meshed sides. + \note This type corresponds to Triangle Preference additional hypothesis, + which is obsolete now. +- Quadrangle preference forces building only quadrangles in the + transition area along the finer meshed sides. This hypothesis has a + restriction: the total quantity of segments on all + four face sides must be even (divisible by 2). + \note This type corresponds to Quadrangle Preference additional hypothesis, + which is obsolete now. +- Quadrangle preference (reversed) works in the same way and + with the same restriction as Quadrangle preference, but + the transition area is located along the coarser meshed sides. +- Reduced type forces building only quadrangles and the transition + between the sides is made gradually, layer by layer. This type has + a limitation on the number of segments: one pair of opposite sides must have + the same number of segments, the other pair must have an even total + number of segments. In addition, the number of rows + between sides with different discretization + should be enough for the transition. Following the fastest transition + pattern, three segments become one (see the image below), hence + the least number of face rows needed to reduce from Nmax segments + to Nmin segments is log3( Nmax / Nmin ). The number of + face rows is equal to the number of segments on each of equally + discretized sides. + +\image html reduce_three_to_one.png "The fastest transition pattern: 3 to 1" + +Base vertex tab allows using Quadrangle: Mapping +algorithm for meshing of trilateral faces. In this case it is +necessary to select the vertex, which will be used as the forth +degenerated side of quadrangle. + +\image html hypo_quad_params_dialog_vert.png "Quadrangle parameters: Base Vertex" \image html hypo_quad_params_1.png "A face built from 3 edges" @@ -68,32 +98,46 @@ shows the good (left) and the bad (right) results of meshing. \image html hypo_quad_params_res_2.png "The resulting meshes" -Type parameter is used on faces with a different number of -segments on opposite sides to define the algorithm of transition -between them. The following types are available: +\image html hypo_quad_params_dialog_enf.png "Quadrangle parameters: Enforced nodes" + +Enforced nodes tab allows defining points, where the +algorithm should create nodes. There are two ways to define positions +of the enforced nodes. + +\note Enforced nodes cannot be created at \b Reduced transition type. +Let us see how the algorithm works: +If there are several enforced vertices, the algorithm is applied +recursively to the formed sub-domains. See Also a sample TUI Script of a \ref tui_quadrangle_parameters "Quadrangle Parameters" hypothesis.