\page blsurf_hypo_page BLSURF Parameters hypothesis
+\anchor blsurf_top
\n BLSURF Parameters hypothesis works only with <b>BLSURF</b> 2d
algorithm. This algorithm is a commercial software.
-
+\n To get a licence, visit http://www.distene.com/corp/eval-distene.html
+
+<ol>
+<li>\ref blsurf_general_parameters "General parameters"</li>
+<li>\ref blsurf_advanced_parameters "Advanced parameters"</li>
+<li>\ref blsurf_local_size "Local size"</li>
+<ol>
+<li type="a">\ref blsurf_sizemap_computation "Computation of the physical size"</li>
+<li type="a">\ref blsurf_attractor "Advanced maps"</li>
+<li type="a">\ref blsurf_attractor_computation "Computation of attractors"</li>
+</ol>
+<li>\ref blsurf_enforced_elements "Enforced vertices"</li>
+<li>\ref blsurf_limitations "Limitations"</li>
+</ol>
+
+\anchor blsurf_general_parameters
<h1>General parameters</h1>
\image html blsurf_parameters.png
<li><b>Patch independent</b> - if checked, geometrical
edges are not respected and all geometrical faces are meshed as one
hyper-face.</li>
+</ul>
+\ref blsurf_top "Back to top"
+
+\anchor blsurf_advanced_parameters
<h1>Advanced parameters</h1>
+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
+<li><b>Verbosity level</b> - Defines the percentage of "verbosity" of
+BLSURF [0-100].</li>
+
<li><b>Topology</b> - allows creation of a conform mesh on a shell of
not sewed faces.
<ul>
<li>"Pre-process" and "Pre-process++" allow the BLSURF software to
pre-process the geometrical model to eventually produce a conform
mesh. </li>
+ <li>"PreCAD" is an auxiliary CAD pre-processing module which has
+ two main goals:
+ <ul>
+ <li> Complete missing or inadequate CAD descriptions.</li>
+ <li> Perform topology reconstruction and specific geometry
+ enhancement for mesh generation.</li>
+ </ul>
+ This module requires a specific licence.
+ \n
+ The following PreCAD options are the most significant and important ones:
+ <ul>
+ <li><b>Merge Edges</b> - allows PreCAD to optimize the geometry by merging some
+ edges. This option is 0 by default.</li>
+ <li><b>Remove nano edges</b> - allows PreCAD to optimize the geometry by removing
+ the nano edges whenever possible. This option is 0 by default.</li>
+ <li><b>Nano edge length</b> - gives the length below which an edge is considered as nano
+ for the topology processing. See also the \b remove_nano_edges option. If unset, PreCAD
+ default value is \f$\mathrm{diag} \times 10^{-5}\f$.</li>
+ <li><b>Discard input topology</b> - computes the CAD topology from scratch,
+ without considering the toplogical information contained in the original CAD
+ (Useful for iges files). This option is 0 by default.</li>
+ </ul>
+ </li>
</ul>
-<li><b>Verbosity level</b> - Defines the percentage of "verbosity" of
-BLSURF [0-100].</li>
+<li><b>ExportGMF</b> - saves the computed mesh into a GMF file (.mesh or .meshb).</li>
-<li><b>Add option</b> - provides the choice of multiple advanced
-options, which appear, if selected, in a table where it is possible to
-input the value of the option and to edit it later.</li>
+<li><b>Add option</b> - provides the choice of multiple PreCAD and BLSURF
+advanced options, which appear, if selected, in a table where it is
+possible to input the value of the option and to edit it later.</li>
-<li><b>Clear option</b> - removes the option selected in the table.
+<li><b>Clear option</b> - removes the option selected in the table.</li>
</ul>
\n
-The following options are commonly usable. 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 BLSURF options are commonly usable.
<ul>
-<li><b>topo_eps1</b> (real) - is the tolerance level inside a CAD
-patch. By default is equal to <i>diag</i> � 10-4. This tolerance is used to
+<li>\b topo_eps1 (real) - is the tolerance level inside a CAD
+patch. By default is equal to \f$\mathrm{diag} \times 10^{-4}\f$. This tolerance is used to
identify nodes to merge within one geometrical face when \b Topology
-option is to pre-process. Default is <i>diag</i>/10.0.</li>
+option is to pre-process.</li>
-<li><b>topo_eps2</b> (real) - is the tolerance level between two CAD
-patches. By default is equal to <i>diag</i> � 10-4. This tolerance is used to
+<li>\b topo_eps2 (real) - is the tolerance level between two CAD
+patches. By default is equal to \f$\mathrm{diag} \times 10^{-4}\f$. This tolerance is used to
identify nodes to merge over different geometrical faces when
-\b Topology option is to pre-process. Default is <i>diag</i>/10.0.</li>
+\b Topology option is to pre-process.</li>
<li>\b LSS (real) - is an abbreviation for "length of sub-segment". It is
-a maximal allowed length of a mesh edge. Default is 0.5.</li>
+a maximal allowed length of a mesh edge. Default is \f$0.5\f$.</li>
<li>\b frontal (integer)
<ul>
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> .
+to</i> <i>P2</i>.
<ul>
-<li>0 - the interpolation is linear: <i>v = h1 + t (h2 - h1 )</i></li>
-<li>1 - the interpolation is geometric: <i>v = h1 * pow( h2/h1, t)</i></li>
-<li>2 - the interpolation is sinusoidal: <i>v = (h1+h2)/2 +
-(h1-h2)/2*cos(PI*t)</i></li>
+<li>0 - the interpolation is linear: \f$v = h1 + t (h2 - h1 )\f$</li>
+<li>1 - the interpolation is geometric: \f$v = h1 \times \left( \frac{h1}{h2} \right)^{t}\f$</li>
+<li>2 - the interpolation is sinusoidal: \f$v = \frac{h1+h2}{2} + \frac{h1-h2}{2 \cdot \cos(\pi \cdot t)}\f$</li>
</ul>
Default is 0.</li>
<li>\b hmean_flag (integer) - determines the computation of the average of several
values:<ul>
<li>-1 - the minimum is computed.</li>
-<li>0 or 2 - the arithmetic average computed.
+<li>0 or 2 - the arithmetic average is computed.
<li>1 - the geometric average is computed.</li>
</ul>
Default is 0.</li>
<li>\b eps_ends (real) - is used to detect the curves whose lengths are very
small, which sometimes constitutes an error. A message is printed
-if<i> fabs(P2-P1) < eps_ends</i>, where <i>P1</i> and <i>P2</i> are the
-extremities of a curve. Default is <i>diag</i>/500.0.</li>
+if \f$\left|P2-P1\right| < eps\_ends\f$, where <i>P1</i> and <i>P2</i> are the
+extremities of a curve. Default is \f$\frac{\mathrm{diag}}{500.0}\f$.</li>
<li>\b prefix (char) - is a prefix of the files generated by
BLSURF. Default is "x".</li>
files. Default is 1.</li>
</ul>
+\n
+The following PreCAD options are commonly usable.
+<ul>
+<li>\b closed_geometry (int) - 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.</li>
+<li>\b debug (int) - If debug = 1 PreCAD will be very verbose and will output
+some intermediate files in the working directory. By default this
+option is 0.</li>
+<li>\b eps_nano_relative (real) - the same as \b eps_nano, but relatively to
+the diagonal of the box bounding the geometry. By default this option is \f$10^{-5}\f$.</li>
+<li>\b eps_sewing (real) - tolerance of the assembly. It rarely requires to be tuned.
+By default this option is \f$\mathrm{diag} \times 5 \cdot 10^{-4}\f$.</li>
+<li>\b eps_sewing_relative (real) - the same as \b eps_nano but relatively to
+the diagonal of the box bounding the geometry. By default this option is \f$5 \cdot 10^{-4}\f$.</li>
+<li>\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.</li>
+<li>\b create_tag_collision (int) - creates new tags from original ones in case
+of collision (entity merge or association for example). By default
+this option is 0.</li>
+<li>\b periodic_tolerance (real) - defines the maximum distance error accepted between
+two sets of periodic entities. By default this option is \f$\mathrm{diag} \times 10^{-5}\f$.</li>
+<li>\b periodic_tolerance_relative (real) - the same as \b
+periodic_tolerance but in a relative unit. Bu default this option is \f$10^{-5}\f$.</li>
+<li>\b periodic_split_tolerance (real) - This periodicity processing related option defines
+the minimum distance between a CAD point and an imprinted point. It allows to indirectly
+control the number of created points and small edges. By default this
+option is \f$\mathrm{diag} \times 10^{-4}\f$.</li>
+<li>\b periodic_split_tolerance_relative (real - the same as \b
+periodic_split_tolerance but in a relative unit. By default this
+option is \f$10^{-4}\f$.</li>
+</ul>
+
\n
The following advanced options are not documented and you can use them
at your own risk.
\n\n Integer variables:
<ul>
<li> addsurf_ivertex</li>
+<li> anisotropic </li>
<li> background </li>
<li> coiter </li>
<li> communication </li>
</ul>
Real variables:
<ul>
-<li> addsurf_angle </li>
-<li> addsurf_R </li>
-<li> addsurf_H </li>
-<li> addsurf_FG </li>
-<li> addsurf_r </li>
-<li> addsurf_PA </li>
-<li> angle_compcurv </li>
-<li> angle_ridge </li>
-<li> eps_pardom </li>
+<li> addsurf_angle </li>
+<li> addsurf_R </li>
+<li> addsurf_H </li>
+<li> addsurf_FG </li>
+<li> addsurf_r </li>
+<li> addsurf_PA </li>
+<li> angle_compcurv </li>
+<li> angle_ridge </li>
+<li> anisotropic_ratio</li>
+<li> eps_pardom </li>
</ul>
String variables:
<ul>
<li> import_option </li>
</ul>
-<h1>Custom size map</h1>
+\ref blsurf_top "Back to top"
-\image html blsurf_parameters_sizemap1.png
+\anchor blsurf_local_size
+<h1>Local size</h1>
-User sizes can be defined on faces, edges or vertices.
+Local sizes can be defined on faces, edges or vertices.
<ul>
<li>The faces, edges and vertices can belong to the meshed geometrical
object or to its sub-shapes (created using <b>Explode</b> command).</li>
</ul></li>
</ul>
+3 different types of size maps can be defined:
+<ol>
+<li type="a">\ref blsurf_sizemap_computation "Computation of the physical size"</li>
+<li type="a">\ref blsurf_attractor "Advanced maps"</li>
+<li type="a">\ref blsurf_attractor_computation "Computation of attractors"</li>
+</ol>
+
+\ref blsurf_top "Back to top"
+
\anchor blsurf_sizemap_computation
<h2>Computation of the physical size</h2>
-\n
+\image html blsurf_parameters_sizemap1.png
+
The physical size is obtained by querying sizemap functions associated to the input CAD object for surfaces, curves and points.
Each function can either return a value h (which is then trimmed
between the two bounds hphymin and hphymax), or "no answer" (by not
</ul>
In order to compute the mean of several values, the arithmetic mean is used by default, but this can be modified by the parameter \ref blsurf_hmean_flag "hmean flag". In the same way, in order to interpolate two values, a linear interpolation is used by default, but this can be modified by \ref blsurf_hinterpol_flag "hinterpol flag".
+\ref blsurf_local_size "Back to \"Local size\"" \n
+\ref blsurf_top "Back to top"
+
\anchor blsurf_attractor
<h2>Advanced maps</h2>
\n
</ul>
</ul>
-\image html blsurf_attractors2.png "Example of mesh created using
-attractors, the attractors here are the side edges and the size grows
-from the side of the surface towards the apex"
-\n
-\image html blsurf_const_size_near_shape2.png "Example of size map
-with constant size option, the size is kept constant on the left side
-of the surface until a certain distance"
-\n
+\image html blsurf_const_size_near_shape2.png "Example of size map with constant size option, the size is kept constant on the left side of the surface until a certain distance"
+
Remark : The validation of the hypothesis might take a few seconds if
attractors are defined or the "constant size" option is used because a
map of distances has to be built on the whole surface for each face
<br><b>See Also</b> a sample TUI Script of the \ref tui_blsurf "creation of a BLSurf hypothesis", including size map.
+\ref blsurf_local_size "Back to \"Local size\"" \n
+\ref blsurf_top "Back to top"
+
\anchor blsurf_attractor_computation
<h2>Computation of attractors</h2>
\n
-The size grows exponentially following the equation : h(d) = User size + (h_start - User Size) * exp( -(d / R)^2 ).
+The size grows exponentially following the equation :
+\f$h(d) = \mathrm{User Size} + (\mathrm{h\_start} - \mathrm{User Size}) \times e ^ { - \left( \frac{d}{R} \right) ^ {2} }\f$
\n
Where :
<ul>
<li>R is called the distance of influence and allows controlling the growth rate of the mesh </li>
</ul>
-<h1>Custom enforced vertices</h1>
+\image html blsurf_attractors2.png "Example of mesh created using attractors, the attractors here are the side edges and the size grows from the side of the surface towards the apex"
+
+\ref blsurf_local_size "Back to \"Local size\"" \n
+\ref blsurf_top "Back to top"
+
+\anchor blsurf_enforced_elements
+<h1>Enforced vertices</h1>
\image html blsurf_parameters_enforced_vertices.png
-It is possible to define some enforced vertices to BLSurf algorithm
-without creating any vertices by CAD algorithms.
+It is possible to define some enforced vertices to BLSurf algorithm.
+An enforced vertex is defined on a Face or a Compound by
+<ul>
+<li> selecting an existing Vertex or Compound,</li>
+<li> or creating a new vertex given its coordinates.</li>
+</ul>
+The enforced vertex is the projection of a point defined by its
+(x,y,z) coordinates on the selected face.
<ul>
-<li>The enforced vertex is the projection of a point defined by its
-(x,y,z) coordinates on the selected face.</li>
<li>It is possible to define several enforced vertices on a face or a group of faces.</li>
<li>If the projected point is on the boundary or outside of the face, it will be ignored.</li>
+<li>If a group name is specified, the enforced nodes will be added in the group. If the group does not exist it will be created.
</ul>
+You can specify BLSURF to use the internal vertices of the faces as enforced vertices by checking <i>Use internal vertices of all faces</i>.
+If a group name is specified, the internal enforced nodes will be added in the group. If the group does not exist it will be created.
+
<br><b>See Also</b> a sample TUI Script of the \ref tui_blsurf "creation of a BLSurf hypothesis", including enforced vertices.
+\ref blsurf_top "Back to top"
+
+\anchor blsurf_limitations
<h1>Limitations</h1>
Currently BLSURF plugin has the following limitations.
</li>
</ul>
+\ref blsurf_top "Back to top"
+
*/
