- <b>Name</b> - allows defining the name of the hypothesis (MG-CADSurf
Parameters_n by default).
-- <b>Physical Mesh</b> - can be set to <em>None</em>, <em>Global size</em>
+- <b>Physical Size</b> group defines a \a physical sizemap.
+
+- \b Type of the physical sizemap can be set to <em>None</em>, <em>Global size</em>
or <em>Local size</em>
- if set to <em>Global size</em>, only the <b>User size</b>,
account the "Gradation" parameter and the custom elements sizes given in the
"Local size" tab.
-- <b>Geometrical mesh</b> - can be set to <em>None</em>, <em>Global size</em>
+- <b>Geometrical Size</b> group defines a \a geometrical sizemap.
+
+- \b Type of the geometrical sizemap can be set to <em>None</em>, <em>Global size</em>
- if set to <em>Global size</em>, allows user input in <b>Mesh angle</b>,
<b>Mesh distance</b> and <b>Gradation</b> fields. These fields control
- <b>Min Size</b> - defines the lower limit of mesh element size. If "Relative value"
is checked, the value is relative to the diagonal of the shape.
-- <b>Gradation</b> - maximum ratio between the lengths of two adjacent edges.
-
-- <b>Quadratic mesh</b> - if checked, quadratic elements will be generated.
-
- <b>Mesh angle</b> - Limiting angle (in degree) between the plane of a triangle of the mesh and each of the tangent planes at the three vertices.
The smaller this angle is, the closer the mesh is to the exact surface, and the denser the resulting mesh is.
- <b>Mesh distance</b> - Maximum desired distance between a triangle and its supporting CAD surface.
The smaller this distance is, the closer the mesh is to the exact surface (only available in isotropic meshing).
-- <b>Anisotropic</b> - if checked, this parameter defines the maximum anisotropic ratio of the metric governing the anisotropic meshing process.
-The default value (0) means that the metric (and thus the generated elements) can be arbitrarily stretched.
-
-- <b>Remove tiny edges</b> - if checked, the tiny (nano) edges are removed from the generated mesh.
-The tiny edge value defines the minimal length under which an edge is considered to be a tiny one.
+- <b>Quadratic mesh</b> - if checked, quadratic elements will be generated.
-- <b>Remove bad elements</b> - if checked, the bad elements (slivers) are removed from the generated mesh.
-The bad element value defines the aspect ratio triggering the "bad element” classification.
+- <b>Gradation</b> - maximum ratio between the lengths of two adjacent edges.
- <b>Mesh optimisation</b> - if checked, the mesh will be optimized in order to get better shaped elements.
- <b>Allow Quadrangles</b> - if checked, allows the creation of quadrilateral elements.
-\ref blsurf_top "Back to top"
-
-\section blsurf_advanced_parameters Advanced parameters
-
-The notion of <i>diag</i> used in the descriptions means the diagonal of the bounding box of the geometrical object to mesh.
-
-\image html blsurf_parameters_advanced.png
-
-- <b>PreCAD options</b> -if checked, the PreCAD module will be used. This module has
-two main goals:
+- <b>Anisotropic</b> - if checked, this parameter defines the maximum anisotropic ratio of the metric governing the anisotropic meshing process.
+The default value (0) means that the metric (and thus the generated elements) can be arbitrarily stretched.
- - Complete missing or inadequate CAD descriptions.
+- <b>Optimize tiny edges</b> - if checked, the tiny (nano) edges are
+ removed from the generated mesh during local mesh optimization. The
+ tiny edge will be removed only if the local quality is improved by
+ the deletion. The tiny edge value defines the minimal length under
+ which an edge is considered to be a tiny one.
- - Perform topology reconstruction and specific geometry
- enhancement for mesh generation.
+- <b>Remove tiny edges</b> - if checked, the tiny (nano) edges are
+ removed from the generated mesh \a without taking into account the
+ local quality around the edge. The tiny edge value defines the
+ minimal length under which an edge is considered to be a tiny one.
- \n This module requires a specific licence. The following PreCAD
- options are the most significant and important ones:
+- <b>Remove bad elements</b> - if checked, the bad elements (slivers) are removed from the generated mesh.
+The bad element value defines the aspect ratio triggering the "bad element” classification.
- - <b>Merge Edges</b> - allows PreCAD to optimize the geometry by merging some
- edges. This option is checked by default.
+- <b>Correct surface intersections</b> - if checked, the mesher will try to prevent all surface intersections, which is useful for future volume mesh generation. The value defines the time that will be spent in the intersection prevention process. For example, the value 3 means that the time of the intersection removal process won't be more than 3 times the time required to mesh without processing the intersections.
- - <b>Process 3D topology</b> - allows PreCAD to perform the cleanup processing.
- This option is checked by default.
+- <b>Volume Gradation</b> - maximum ratio between the lengths of two adjacent edges affecting quality of a future volume mesh, specially in thin volume areas. The volume gradation parameter must be greater than 1, and should be greater or equal to the value of the classic
+surface gradation (at the risk of increasing the time of convergence of the gradation process).
+The closer it is to 1, the smoother the final volume mesh you will build should be.
- - <b>Discard input topology</b> - computes the CAD topology from scratch,
- without considering the topological information contained in the original CAD
- (useful for iges files). This option is unchecked by default.
-- <b>Verbosity level</b> - defines the percentage of "verbosity" of
-MeshGems-CADSurf and MeshGems-PreCAD [0-10].
-- <b>ExportGMF</b> - saves the computed mesh into a GMF file (.mesh or .meshb).
+\ref blsurf_top "Back to top"
-- <b>Add option</b> - provides the choice of multiple PreCAD and MG-CADSurf
-advanced options, which appear, if selected, in a table where it is
-possible to input the value of the option and edit it later.
+\section blsurf_advanced_parameters Advanced parameters
-- <b>Clear option</b> - removes the option selected in the table.
+The notion of <i>diag</i> used in the descriptions means the diagonal of the bounding box of the geometrical object to mesh.
-The following MG-CADSurf options are commonly usable:
+\image html blsurf_parameters_advanced.png
-- \b frontal (integer)
+\b Advanced page tab expose mostly useful advanced options. Initially, default values of the options are displayed and they are not modifiable. If an option is activated using a check-box, its value becomes modifiable.
- - 1 - the mesh generator inserts points with an advancing front method.
+- \b Meshing options
- - 0 - it inserts them with an algebraic method (on internal edges). This method is
- slightly faster but generates less regular meshes.
+ - <b>Enforce CAD edge sizes</b> - Relaxes the given sizemap constraint around CAD edges to allow a better
+element quality and a better geometric approximation. It is only useful in combination with the
+gradation option.
- \n Default is 1.
+ - <b>Priority of geometry over Jacobian</b> - This parameter determines whether or not the geometry accuracy
+is more important than the negative Jacobian correction. When this parameter is set to 0,
+MeshGems-CADSurf is allowed to lose the CAD-mesh associativity in order to correct the last negative Jacobians.
-- \anchor blsurf_hinterpol_flag \b hinterpol_flag (integer) - determines the computation of an
-interpolated value <i>v</i> between two points <i>P1</i> and <i>P2</i> on a
-curve. Let <i>h1</i> be the value at point <i>P1,</i> <i>h2</i> be the value at point
-<i>P2,</i> and <i>t</i> be a parameter varying from 0 to 1 when moving from <i>P1
-to</i> <i>P2</i>.
+ - <b>Maximal number of points per patch</b> - This parameter controls the maximum amount of points MeshGems-CADSurf
+is allowed to generate on a single CAD patch. For an automatic gestion of the memory, you can set this parameter to ”0”.
- - 0 - the interpolation is linear: \f$v = h1 + t (h2 - h1 )\f$
+ - <b>Rectify Jacobian</b> - The quadratic elements generation is a processing of the MeshGems-CADSurf
+meshing process which inserts the extra nodes on the CAD. This parameter determines whether
+MeshGems-CADSurf will try to correct or not all the elements of the surface mesh with negative
+Jacobians by moving the internal nodes of the mesh.
- - 1 - the interpolation is geometric: \f$v = h1 \times \left( \frac{h1}{h2} \right)^{t}\f$
+ - <b>Respect geometry</b> - This patch independent option can be deactivated to allow MeshGems-CADSurf
+to lower the geometry accuracy in its patch independent process.
- - 2 - the interpolation is sinusoidal: \f$v = \frac{h1+h2}{2} + \frac{h1-h2}{2 \cdot \cos(\pi \cdot t)}\f$
+ - <b>Tiny edges avoid surface intersections</b> - This option defines the priority between the tiny feature
+suppression and the surface intersection prevention. By default, MeshGems-CADSurf gives the priority
+to the surface intersection prevention rather than to tiny edge or bad surface element removal. These
+mesh features are then removed only if it does not lead to surface intersections. This behaviour can be
+deactivated by setting this parameter to 0, giving priority to the tiny edge or bad surface element
+removal.
- \n Default is 0.
+ - <b>use deprecated patch mesher</b> - This option reproduces the mesher behaviour of previous MG-CADSurf versions
+(MeshGems before 2.3, i.e. before SALOME 8.2). This has proved useful on some particular cases such as very small
+local size on a vertex situated on a border curve.
-- \anchor blsurf_hmean_flag \b hmean_flag (integer) - determines the computation of the average of several
-values:
+- <b>CAD preprocessor</b> options. The CAD preprocessor (formerly known as PreCAD) has two main goals:
- - -1 - the minimum is computed.
+ - Complete missing or inadequate CAD descriptions.
- - 0 or 2 - the arithmetic average is computed.
+ - Perform topology reconstruction and specific geometry
+ enhancement for mesh generation.
- - 1 - the geometric average is computed.
+ \n All options are unchecked by default. No cleanup is made by default so that the mesh matches the shape. If the user has a bad shape (e.g. imported shape), he can activate some options to improve the mesh.
- \n Default is 0.
+ - <b>Closed geometry</b> - describes whether the working geometry should be closed or not.
+ When activated, this option helps PreCAD to process the dirtiest geometries.
-The following PreCAD options are commonly usable.
+ - \b Debug - If debug = yes PreCAD will be very verbose and will output some intermediate files in the working directory.
-- \b closed_geometry (boolean) - describes whether the working geometry
-should be closed or not. When activated, this option helps PreCAD to process
-the dirtiest geometries. By default this option is 0.
+ - <b>Discard input topology</b> - compute the CAD topology from scratch,
+ without considering the topological information contained in the original CAD
+ (useful for iges files). This option is unchecked by default.
-- \b create_tag_collision (boolean) - creates new tags from original ones in case
-of collision (entity merge or association for example). By default
-this option is 1.
+ - <b>Merge Edges</b> - optimize the geometry by merging some
+ edges.
-- \b debug (bool) - If debug = 1 PreCAD will be very verbose and will output
-some intermediate files in the working directory. By default this
-option is 0.
+ - <b>Periodic tolerance</b> - This parameter defines the maximum size difference between two periodic edges and also the maximum distance error between two periodic entities.
-- \b manifold_geometry (int) - describes whether the working geometry should be manifold or not.
-When activated, this option helps PreCAD to process the dirtiest
-geometries. By default this option is 0.
+ - <b>Remove duplicate CAD faces</b> - optimize the geometry by merging the
+ duplicate CAD faces. This option is unchecked by default.
-- \b periodic_tolerance (real) - defines the maximum distance error accepted between
-two sets of periodic entities. By default this option is \f$\mathrm{diag} \times 10^{-5}\f$.
+ - <b>Required entities</b> - The required entities control the correction operations. Accepted values for this parameter are:
+ - respect : MeshGems-CADSurf is not allowed to alter any required entity, even for correction purposes,
+ - ignore : MeshGems-CADSurf will ignore the required entities in its processing,
+ - clear : MeshGems-CADSurf will clear any required status for the entities. There will not be any entity marked as required in the generated mesh.
-- \b remove_tiny_edges (boolean) -optimize the geometry by removing the nano edges whenever possible.
-By default this option is 0.
+ - <b>Sewing tolerance</b> - tolerance of the assembly. It rarely requires to be tuned.
-- \b required_entities (char) -controls the correction operations. Possible values are:
+ - \b Tags - controls the optimisation process. Possible values are:
+ - "respect" - PreCAD is not allowed to cross the CAD attributes boundaries for optimisation purpose.
+ - "ignore" - PreCAD is allowed to cross the CAD attributes boundaries for optimisation.
+ - "clear" - PreCAD will erase each tgas of each entities, and will thus be allowed to cross the CAD attributes boundaries in its optimisation purpose.
- - "respect" - PreCAD is not allowed to correct or optimize a required edge.
- - "ignore" - PreCAD is allowed to correct a required edge.
+- <b>Add option</b> - adds a new line in <b>Other options</b> section where you can type an option name and value. The following advanced MG-CADSurf options can be used:
- - "clear" - PreCAD will erase "required" status of each required entities, and will thus
- be allowed to correct a required edge.
+ - \b create_tag_on_collision (bool) - If this option is activated, MeshGems-CADSurf will create new tags to
+ describe tag collisions (when it locally changes the topology, depending on the patch independent
+ options). When this option is not activated, only one tag is preserved while the other one is dropped.
+ By default this option is 1.
- \n By default this option is "respect".
+ - \b tiny_edge_respect_geometry (bool) - This option defines the behaviour of the tiny edge removal algorithm
+ regarding volume collapse. By default, all tiny edges will be removed, regardless of any potential
+ volume collapse. When this option is activated, it will prevent volume from being collapsed during the tiny edge removal process.
+ By default this option is 0.
-- \b sewing_tolerance (real) - tolerance of the assembly. It rarely requires to be tuned.
-By default this option is \f$\mathrm{diag} \times 5 \cdot 10^{-4}\f$.
+ - \b manifold_geometry (int) - describes whether the working geometry should be manifold or not.
+ When activated, this option helps PreCAD to process the dirtiest
+ geometries. By default this option is 0.
-- \b tags (char) -controls the optimisation process. Possible values are:
- - "respect" - PreCAD is not allowed to cross the CAD attributes boundaries for optimisation purpose.
- - "ignore" - PreCAD is allowed to cross the CAD attributes boundaries for optimisation.
+- <b>Verbosity level</b> - defines the percentage of "verbosity" of
+MeshGems-CADSurf [0-10].
- - "clear" - PreCAD will erase each tgas of each entities, and will thus
- be allowed to cross the CAD attributes boundaries in its optimisation purpose.
+- <b>ExportGMF</b> - saves the computed mesh into a GMF file (.mesh or .meshb).
- \n By default this option is "respect".
-- \b tiny_edge_length (real) - the length below which en edge is considered as nano for the topology processing.
-By default this option is \f$10^{-5}\f$.
\ref blsurf_top "Back to top"
interpolate two values, a linear interpolation is used by default, but
this can be modified by \ref blsurf_hinterpol_flag "hinterpol flag".
+<b>Note:</b> on some particular configurations, the mesher behaviour is
+not the same as before (SALOME versions before 8.2 i.e. MeshGems before 2.3).
+For a small local size defined on a point situated on a border curve,
+the previous mesher behaviour may be prefered:
+see "use deprecated patch mesher"
+on advanced tag.
+
+
\ref blsurf_local_size "Back to \"Local size\""\n
\ref blsurf_top "Back to top"
\image html blsurf_parameters_enforced_vertices.png
It is possible to define some enforced vertices to MG-CADSurf algorithm.
-An enforced vertex is defined on a Face or a Compound by
+An enforced vertex is defined by
- selecting an existing Vertex or Compound,
-- or creating a new vertex given its coordinates.
+- or by its coordinates.
The enforced vertex is the projection of a point defined by its
-(x,y,z) coordinates on the selected face.
+(x,y,z) coordinates on the closest face found by the application.
-- It is possible to define several enforced vertices on a face or a group of faces.
+- It is possible to define several enforced vertices.
- If the projected point is on the boundary or outside of the face, it will be ignored.
-- If a group name is specified : If the group exists, the enforced nodes will be added in the existing group, if the group does not exist it will be created.
+- If a group name is specified : if the group exists, the enforced nodes will be added in the existing group, if the group does not exist it will be created.
-All the internal vertices of the faces can be considered as enforced vertices if the corresponding checkbox is checked.
+All the internal vertices of faces can be considered as enforced vertices if the corresponding checkbox is checked.
A group can optionnaly be defined on those enforced vertices.
\sa Sample TUI Script of the \ref tui_blsurf "creation of a MG-CADSurf hypothesis", including enforced vertices.
Periodicity is used to have the same discretization on two faces (in 3D) or two edges (in 2D).
This is useful for instance for a Representative Volume Element so that the translated meshes share the same nodes on the common faces.
-In GUI, periodicity association uses PreCAD (optional MG-CADSurf add-on). Be sure to have a PreCAD license to be able to use it. Otherwise, use \ref periodicity_tui_basic_api_usage "the basic API in TUI" or the \ref periodicity_tui_advanced_api_usage "the advanced API in TUI".
+Periodicity association uses PreCAD (MG-CADSurf preprocessor). You don't need an extra PreCAD license. It is included in MG-CADSurf since MeshGems V2.2.
\image html blsurf_periodicity_translation.png "Two periodic faces (translation)"
The two methods to define periodicity with PreCAD are
(the former name of <em>MG-CADSurf</em> is \a BLSURF and names
of the corresponding classes and modules still include \a "BLSURF"):
-- BLSURFPluginBuilder.BLSURF_Algorithm.AddPreCadFacesPeriodicity
+- BLSURFPluginBuilder.BLSURF_Algorithm.AddPreCadFacesPeriodicity
- BLSURFPluginBuilder.BLSURF_Algorithm.AddPreCadEdgesPeriodicity
List of source and target vertices to define a transformation are optional.
\sa Sample TUI Script of the definition of MG-CADSurf periodicity \ref tui_blsurf_periodicity_preCAD "using preCAD".
-\subsection periodicity_tui_basic_api_usage TUI Basic API usage
+\section blsurf_hyperpatch Hyper-patch
-In the CADSurf basic API, only available in TUI, the periodicity must be defined face by face, edge by edge and vertex by vertex.
+\image html blsurf_parameters_hyperpatch.png
-The methods are:
-- BLSURFPluginBuilder.BLSURF_Algorithm.AddFacePeriodicity
-- BLSURFPluginBuilder.BLSURF_Algorithm.AddEdgePeriodicity
-- BLSURFPluginBuilder.BLSURF_Algorithm.AddEdgePeriodicityWithoutFaces
-- BLSURFPluginBuilder.BLSURF_Algorithm.AddVertexPeriodicity
+Hyper-patch tab page allows defining faces that will be meshes together as
+ part of a global hyper-patch.
-Sample TUI Script of the definition of MG-CADSurf periodicity \ref tui_blsurf_periodicity_basic "using basic API (without preCAD)".
+- <b>Hyper-patch IDs</b> table - shows IDs of faces of defined hyper-patches.
-\subsection periodicity_tui_advanced_api_usage TUI Advanced API usage
+- <b>Face selection</b> - activates selection of faces in the VTK Viewer.
-To ease the periodicity description, the basic API methods can be called through two advanced methods, given two geom groups and a python geom transformation:
+- <b>Group selection</b> - activates selection of faces and groups of
+ faces in the Object Browser.
-- BLSURFPluginBuilder.BLSURF_Algorithm.AddAdvancedFacesPeriodicity (in 3D)
-- BLSURFPluginBuilder.BLSURF_Algorithm.AddAdvancedEdgesPeriodicity (in 2D)
+- \b IDs - allows typing IDs of faces composing a hyper-patch and
+ shows IDs of faces selected in the Viewer or the Object Browser.
-Sample TUI Script of the definition of MG-CADSurf periodicity \ref tui_blsurf_periodicity_advanced "using advanced API (without preCAD)".
+- \b Add - adds a new row to the table and moves \b IDs there.
+
+- \b Remove - removes selected hyper-patches from the table.
\ref blsurf_top "Back to top"
+For more information on MeshGems-CADSurf, you can read its documentation at $MESHGEMS_ROOT_DIR/Docs/mg-cadsurf_user_manual.pdf
+
*/
