0021336: EDF 1717 SMESH: New algorithm "body fitting" cartesian unstructured

doc/salome/gui/SMESH/input/basic_meshing_algos.doc

@@ -23,10 +23,8 @@ shape of a mesh.</li>
 <ul>
 <li>Triangle meshing algorithms (Mefisto, Netgen 1D-2D and BLSUFR ) - Faces
 are split into triangular elements.</li>
-<li>Quadrangle meshing algorithm (Mapping) - Faces are split into
+<li>Quadrangle meshing algorithm (Mapping) - quadrilateral Faces are split into
 quadrangular elements.</li>
-<li>Radial quadrangle 1D2D algorithm - Faces (circles or part of circles)
-are split into triangular and quadrangle elements.</li>
 </ul>
 
 \image html image123.gif "Example of a triangular 2D mesh"
@@ -36,10 +34,14 @@ are split into triangular and quadrangle elements.</li>
 <li>For meshing of 3D entities (<b>volume objects</b>):</li>
 
 <ul>
-<li>Hexahedron meshing algorithm (i,j,k) - Volumes are split into
+<li>Hexahedron meshing algorithm (i,j,k) - 6-sided Volumes are split into
 hexahedral (cubic) elements.</li>
 <li>Tetrahedron (Netgen and GHS3D) meshing algorithms - Volumes are split into
 tetrahedral (pyramidal) elements.</li>
+<li>\subpage cartesian_algo_page</li>
+internal part of Volumes are split into hexahedral elements forming a
+Cartesian grid; polyhedra and other types of elements are gerenated
+where the geometrical boundary intersects Cartesian cells.</li>
 </ul>
 
 \image html image125.gif "Example of a tetrahedral 3D mesh"

doc/salome/gui/SMESH/input/cartesian_algo.doc

@@ -0,0 +1,75 @@
+/*!
+
+\page cartesian_algo_page Body Fitting 3D meshing algorithm
+
+Body Fitting algorithm generates hexahedrones of a Cartesian grid in
+the internal part of geometry and polyhedra and other types of
+elements at intersection of Cartesian cells with the geometrical
+boundary.
+
+\image html cartesian3D_sphere.png "A shpere meshed by Body Fitting algorithm"
+
+Algorithm of meshing is following.
+<ol>
+<li> Lines of a Cartesian structured grid defined by
+\ref cartesian_hyp_anchor "Body Fitting Parameters" hypothesis are
+intersected with the geometry boundary, thus nodes laying on the
+boundary are found. This step also allows finding out for each node of
+the Cartesian grid if it is inside or outside the geometry. </li>
+<li> For each cell of the grid, check how many of it's nodes are outside
+of the geometry boundary. Depending on a result of this check
+<ul>
+<li> skip a cell, if all it's nodes are outside </li>
+<li> skip a cell, if it is too small according to <b> Size
+    Threshold </b> paremeter</li>
+<li> add a hexahedron in the mesh, if all nodes are inside </li>
+<li> add a polyhedron or a cell of other type in the mesh, if some
+nodes are inside and some outside </li> 
+</ul>
+</li>
+</ol>
+To apply this algorithm, when you define your mesh, select <b>Body
+  Fitting</b> in the list of 3D algorithms and click <em>"Add
+  Hypothesis"</em> button and <em>"Body Fitting Parameters"</em>" menu
+  item. Dialog of <b> Body Fitting Parameters
+  hypothesis</b> will appear.
+
+<br>
+\anchor cartesian_hyp_anchor
+<h2>Body Fitting Parameters hypothesis</h2>
+
+\image html cartesian3D_hyp.png "Body Fitting Parameters hypothesis dialog"
+
+This dialog lets you define
+<ul>
+<li>\b Name of the algorithm </li>
+<li> Minimal size of a cell truncated be the geometry boundary. If
+  size of a truncated grid cell is \b Threshold times less than a
+  initial cell size, then a mesh element is not created. </li>
+<li> Cartesian structured grid. Each grid axis is defined
+  individually. <b> Definition mode </b> chooses a way of grid
+  definition: <ul> 
+  <li> You can specify \b Coordinates of grid nodes. \b Insert button
+    inserts a node at distance \b Step (negative or positive) from a
+    selected node. \b Delete botton removes a selected node. Double
+    click on a coordinate in the list enables its edition. A grid
+    defined by \b Coordinates should enclose the geometry, else the
+    algorithm will fail. </li>
+  <li> You can define \b Spacing of a grid as an algebraic formular 
+    <em>f(t)</em> where \a t is a position along a grid axiz
+    normalized at [0.0,1.0]. The whole range of geometry can be
+    divided into sub-ranges with their own spacing formulars to apply;
+    \a t varies between 0.0 and 1.0 within each sub-range. \b Insert button
+    divides a selected range into two ones. \b Delete button adds a
+    selected sub-range to a previous one. Double click on a range in
+    the list enables edition of its right boundary. Double click on a
+    function in the list enables its edition. 
+  </li> </ul>
+</li>
+</ul>
+
+<br>
+<b>See Also</b> a sample TUI Script of a 
+\ref tui_cartesian_algo "Usage of Body Fitting algorithm".  
+
+*/

doc/salome/gui/SMESH/input/tui_cartesian_algo.doc

@@ -0,0 +1,49 @@
+/*!
+
+\page tui_cartesian_algo Usage of Body Fitting algorithm
+
+\code
+from smesh import *
+SetCurrentStudy(salome.myStudy)
+
+# create a sphere
+sphere = geompy.MakeSphereR( 50 )
+geompy.addToStudy( sphere, "sphere" )
+
+# create a mesh and assign a "Body Fitting" algo
+mesh = Mesh( sphere )
+cartAlgo = mesh.BodyFitted()
+
+# define a cartesian grid using Coordinates
+coords = range(-100,100,10)
+cartHyp = cartAlgo.SetGrid( coords,coords,coords, 1000000)
+
+# compute the mesh
+mesh.Compute()
+print "nb hexahedra",mesh.NbHexas()
+print "nb tetrahedra",mesh.NbTetras()
+print "nb polyhedra",mesh.NbPolyhedrons()
+print
+
+# define the grid by sitting constant spacing
+cartHyp = cartAlgo.SetGrid( "10","10","10", 1000000)
+
+mesh.Compute()
+print "nb hexahedra",mesh.NbHexas()
+print "nb tetrahedra",mesh.NbTetras()
+print "nb polyhedra",mesh.NbPolyhedrons()
+
+
+# define the grid by sitting different spacing in 2 sub-ranges of geometry
+spaceFuns = ["5","10+10*t"]
+cartAlgo.SetGrid( [spaceFuns, [0.5]], [spaceFuns, [0.5]], [spaceFuns, [0.25]], 2 )
+
+mesh.Compute()
+print "nb hexahedra",mesh.NbHexas()
+print "nb tetrahedra",mesh.NbTetras()
+print "nb polyhedra",mesh.NbPolyhedrons()
+print
+
+\endcode
+
+*/

src/SMESH_I/SMESH_2smeshpy.cxx

@@ -1665,6 +1665,16 @@ Handle(_pyHypothesis) _pyHypothesis::NewHypothesis( const Handle(_pyCommand)& th
     hyp = new _pyLayerDistributionHypo( theCreationCmd, "Get3DHypothesis" );
     hyp->SetConvMethodAndType( "LayerDistribution", "RadialPrism_3D");
   }
+  // Cartesian 3D ---------
+  else if ( hypType == "Cartesian_3D" ) {
+    algo->SetConvMethodAndType( "BodyFitted", hypType.ToCString());
+  }
+  else if ( hypType == "CartesianParameters3D" ) {
+    hyp = new _pyComplexParamHypo( theCreationCmd );
+    hyp->SetConvMethodAndType( "SetGrid", "Cartesian_3D");
+    for ( int iArg = 0; iArg < 4; ++iArg )
+      hyp->myArgs.Append("[]");
+  }
 
   return algo->IsValid() ? algo : hyp;
 }
@@ -1835,12 +1845,44 @@ void _pyHypothesis::Assign( const Handle(_pyHypothesis)& theOther,
 //================================================================================
 /*!
  * \brief Remember hypothesis parameter values
-  * \param theCommand - The called hypothesis method
+ * \param theCommand - The called hypothesis method
  */
 //================================================================================
 
 void _pyComplexParamHypo::Process( const Handle(_pyCommand)& theCommand)
 {
+  if ( GetAlgoType() == "Cartesian_3D" )
+  {
+    // CartesianParameters3D hyp
+
+    if ( theCommand->GetMethod() == "SetSizeThreshold" )
+    {
+      myArgs( 4 ) = theCommand->GetArg( 1 );
+      myArgCommands.push_back( theCommand );
+      return;
+    }
+    if ( theCommand->GetMethod() == "SetGrid" ||
+         theCommand->GetMethod() == "SetGridSpacing" )
+    {
+      TCollection_AsciiString axis = theCommand->GetArg( theCommand->GetNbArgs() );
+      int iArg = 1 + ( axis.Value(1) - '0' );
+      if ( theCommand->GetMethod() == "SetGrid" )
+      {
+        myArgs( iArg ) = theCommand->GetArg( 1 );
+      }
+      else
+      {
+        myArgs( iArg ) = "[ ";
+        myArgs( iArg ) += theCommand->GetArg( 1 );
+        myArgs( iArg ) += ", ";
+        myArgs( iArg ) += theCommand->GetArg( 2 );
+        myArgs( iArg ) += "]";
+      }
+      myArgCommands.push_back( theCommand );
+      return;
+    }
+  }
+
   if( theCommand->GetMethod() == "SetLength" )
   {
     // NOW it becomes OBSOLETE