mirror of
https://git.salome-platform.org/gitpub/modules/smesh.git
synced 2024-09-23 11:12:51 +05:00
0921263864
Fix a leak of PropagationMgrData + Do not use volumes for preview of Extrusion + Fix a regression: empty groups are not removed with contents + avoid too long waiting at creation of hypotheses due to use of GEOMUtils::PreciseBoundingBox() in SMESH_Mesh::GetShapeDiagonalSize()
50 lines
2.2 KiB
Plaintext
50 lines
2.2 KiB
Plaintext
/*!
|
|
|
|
\page quad_ijk_algo_page Quadrangle (Mapping) meshing algorithm
|
|
|
|
<b>Quadrangle (Mapping)</b> meshing algorithm is intended for creating
|
|
all-quadrangle and quad-dominant meshes on faces with no holes and
|
|
bound by at least three edges.
|
|
|
|
The algorithm can create mesh on any face but mesh quality and
|
|
validity depends on two factors:
|
|
- face shape (number of edges and concavity of boundary);
|
|
- discretization of edges.
|
|
|
|
\image html quad_mesh_invalid.png "Invalid mesh on quadrilateral concave faces"
|
|
|
|
The algorithm uses <em>Transfinite Interpolation</em> technic in
|
|
parametric space of a face to locate nodes inside the face.
|
|
|
|
The algorithm treats any face as a quadrangle. If a face is bound by
|
|
more than four edges, four most sharp vertices are considered as
|
|
corners of the quadrangle and all edges between these vertices are
|
|
treated as quadrangle sides. In the case of three edges, the vertex
|
|
specified by the user is considered as a degenerated side of the
|
|
quadrangle.
|
|
|
|
\image html quad_meshes.png "Algorithm generates a structured mesh on complex faces provided that edges are properly discretized"
|
|
|
|
To get an all-quadrangle mesh you have to carefully define 1D
|
|
hypotheses on edges of a face. To get a \b structured mesh you have to assure
|
|
equal number of segments on opposite sides of the quadrangle. If this
|
|
condition is not respected, the algorithm by default (with no
|
|
hypothesis) creates \b quad-dominant mesh with triangles located near a
|
|
side with maximal number of segments. But you can get an
|
|
\b all-quadrangle mesh in this case by using
|
|
\ref hypo_quad_params_anchor "Quadrangle Parameters"
|
|
hypothesis to specify how to make transition mesh between opposite
|
|
sides with different number of segments, provided that certain
|
|
conditions are respected. In any case total number of segments must be
|
|
even. To use \a Reduced transition method there must be equal number
|
|
of segments on one pair of opposite sides.
|
|
|
|
The following hypotheses help in creation of quadrangle meshes.
|
|
- \ref propagation_anchor "Propagation" additional 1D hypotheses
|
|
help to get equal number of segments on opposite sides of the
|
|
quadrilateral face.
|
|
- \ref a1d_algos_anchor "Composite Side Discretization" algorithm is useful
|
|
to discretize several C1 continues edges as one quadrangle side.
|
|
|
|
*/
|