finished doc, moved figs to large_media refs idaholab#21903

framework/doc/content/source/meshgenerators/TransfiniteMeshGenerator.md

@@ -9,30 +9,40 @@ The `TransfiniteMeshGenerator` produces two-dimensional meshes from a set of 4 c
 !media media/meshgenerators/quad_convention.png style=float:right;width:20%;margin-left:2%; caption=Fig. 1: Convention for the corner vertices order.
 
 Given a set of 4 corners the TransfiniteMeshGenerator constructs by default the straight edges that connect the vertices and fills up the interior with straight lines. The test, [quadrilater_generator.i](test/tests/meshgenerators/transfinite_generator/quadrilater_generator.i),
-illustrates the use of the `TransfiniteMeshGenerator` object to construct general quadrilaterals. The convention for the corners numbering should follow Fig. 1, prescribed in the order +(0,0) - (0,1) - (1,1) - (1,0)+. The direction along edges, important in case they are user provided using the DISCRETE option, should follow the direction in Fig. 1.
+illustrates the use of the `TransfiniteMeshGenerator` object to construct general quadrilaterals as in Fig. 2. By default the distribution of points along edges is considered equidistant, unless specified otherwise by the user using the parameters `bias_x` or `bias_y`. The core of the algorithm interpolates/fills up the inner domain for any edge type, curved, parametrized, discrete. The current implementation considers all these cases with special attention given to arcs of a circle which are widely encountered in scientific computing applications. 
 
-This generator allows any type of curvilinear edges. In Fig. 2 we show a mesh where the bottom edge has an inward arc circle. However, this algorithm generates a mesh for any parametrized edge, or given set of points on an edge. For arcs of a circle, since they are widely encounterened in applications, we customized an approach that requires from an user to specify only the deviation from a straight line in the middle of an edge. 
+The convention for the corners numbering should follow Fig. 1, prescribed in the order +(0,0) - (0,1) - (1,1) - (1,0)+. The direction along edges, important if the user provides them using the DISCRETE option, should follow the direction of the arrows as in Fig. 1.
 
-The distribution of points on an edge can be either provided as a discrete set of points, using the edge type `DISCRETE`, or as a bias along the edge. The only requirement is that opposite edges have the same number of points.
+!media large_media/framework/meshgenerators/transfinite_quadrilateral_sm.png style=float:right;margin:2%;width:30%; caption=Fig. 2: A quadrilateral with one edge on an arc circle.
+
+This generator allows any type of curvilinear edges. In Fig. 2 we show a mesh where the bottom edge has an inward arc circle. However, this algorithm generates a mesh for any parametrized edge, or given set of points on an edge. For arcs of a circle, since they are widely encountered in applications, we customized an approach that requires a user to specify only the deviation from a straight line in the middle of an edge. 
 
-!media media/meshgenerators/mesharc.png style=float:right;margin:2%;width:30%; caption=Fig. 2: A quadrilateral with one edge on an arc circle.
+The distribution of points on an edge can be either provided as a discrete set of points, using the edge type `DISCRETE`, or as a bias along the edge. The only requirement is that opposite edges have the same number of points.
 
 ## Example 
 
+!media large_media/framework/meshgenerators/transfinite_arccircle_annular_sm.png style=float:right;margin:2%;width:20%; caption=Fig. 3: A quadrilateral with one edge on an arc circle.
+
 
 This mesh generator considers 4 types of edges defined in `edge_type`, where `edge` is either left, right, top or bottom.
 
+  - `LINE`, constructs a line between provided corner vertices.
+
+  - `CIRCARC`, constructs an arc of a circle and requires an additional parameter, named `edge_parameter`. This parameter can be the distance at the middle of an edge between a straight line and the arc of circle desired, as in the test [arccircle_generator.i](test/tests/meshgenerators/transfinite_generator/arcircle_generator.i). The edge is then generated by computing the middle point on the edge. The deviation from a straight line is set by convention to be positive if the arc circle is outward, or negative if inward, in this fashion the user can specify different orientations. 
+  The midpoint could also be obtained from a QUAD8 element as provided by an external mesh generator and inserted as input by the user in the same  `edge_parameter`, as in the test [arccircle_midpoint_generator.i](test/tests/meshgenerators/transfinite_generator/arcircle_midpoint_generator.i).
+
+
+!media large_media/framework/meshgenerators/transfinite_discrete_arccircle_sm.png style=float:right;margin:2%;width:25%; caption=Fig. 4: A quadrilateral with one edge on an arc circle.
+
+  - `DISCRETE`, constructs a line along a set of points provided by the user in the order represented by arrows in Fig. 1, a test is available in [discrete_generator.i](test/tests/meshgenerators/transfinite_generator/discrete_generator.i) and illustrated in Fig. 4. This option is the only one that does not support a different point redistribution since it is assumed the user desires those edge points explicitely. Along an edge described by this option the `bias_x` and `bias_y` parameters will have no effect. 
 
-- `LINE`, constructs a line between provided corner vertices
-- `ARCCIRC`, constructs an arc of a circle and requires an additional parameter, the distance at the middle of an edge between a straight line and the arc of circle desired. The edge is then generated by computing the middle point on the edge, which could be also obtained from a QUAD8 element from a mesh generator (if this capability is desired by a user please address the developers, as it is easy to adjust) 
-- `DISCRETE`, constructs a line along a set of points provided by the user in the order represented by arrows in Fig. 1, a test is available as [discrete_generator.i](test/tests/meshgenerators/transfinite_generator/discrete_generator.i).
-- `PARSED`, constructs a curvilinear edge as provided by a parametrization chosen by the user.
+  - `PARSED`, constructs a curvilinear edge as provided by a parametrization chosen by the user. The test [parsed_generator.i](test/tests/meshgenerators/transfinite_generator/parsed_generator.i) constructs a stenotic pipe using the parametrization of the top and bottom edges. The only requirement the user needs to take into account is to map the parametrization to the reference interval `[0, 1]`. 
 
 
-Each edge type may require additional parameters specified as `edge_parameter`, unless the edge is a line. For an arc circle and the deviation from a straight line is set by convention to be positive if the arc circle is outward, or negative if inward, as in Fig. 2, see test [arccircle_generator.i](test/tests/meshgenerators/transfinite_generator/arccircle_generator.i)
+!media large_media/framework/meshgenerators/transfinite_parsed_bias_sm.png style=float:right;margin:2%;width:30%; caption=Fig. 5: A quadrilateral with one edge on an arc circle.
 
+Since opposite sides need to have the same number of points, we consider top-bottom edges to have `nx` points, and left-right edges `ny` points. By default they are taken to be equidistant, unless the user specifies a distancing via the parameters `bias_x` or `bias_y`. Different point distributions can propagate on curvilinear edges, generating domains as in Fig. 5. Note that the bias across an edge is implemented as propapagted by the parametrization, so for a parametrized edge $x(r),\ y(r)$ the bias is constructed first for the parameter $r$ and propagated as the parametrized edge is generated. 
 
-Two opposite sides need to have the same number of points, and we consider top-bottom edges to have `nx` points, and left-right edges `ny` points. By default they are taken to be equidistant, unless the user specifies a distancing via the parameters `bias_x` or `bias_y`.
 
 
 !syntax parameters /Mesh/TransfiniteMeshGenerator

framework/src/meshgenerators/TransfiniteMeshGenerator.C

@@ -43,7 +43,7 @@ TransfiniteMeshGenerator::validParams()
   params.addRequiredParam<unsigned int>("ny",
                                         "Number of Nodes on vertical edges, including corners");
 
-  // each edge has a different paramter according to its type
+  // each edge has a different parameter according to its type
   params.addParam<std::string>("bottom_parameter", "", "Bottom side support parameter");
   params.addParam<std::string>("top_parameter", "", "Top side support parameter");
   params.addParam<std::string>("left_parameter", "", "Left side support parameter");
@@ -60,8 +60,6 @@ TransfiniteMeshGenerator::validParams()
       "bias_y>=1.0 & bias_y<=2",
       "The amount by which to grow (or shrink) the cells in the y-direction.");
 
-  // params.addParam<FunctionName>("top_function",
-  //                            "Function expression encoding a paramterization of an edge");
   params.addClassDescription("Creates a QUAD4 mesh given a set of corner vertices and edge types. "
                              "The edge type can be either LINE, CIRCARC, DISCRETE or PARSED, with "
                              "LINE as the default option. "
@@ -75,6 +73,10 @@ TransfiniteMeshGenerator::validParams()
                              "distribution can be prescribed "
                              "via the options bias_x or bias_y for opssiong edges.");
 
+  params.addParamNamesToGroup("bottom_type left_type top_type right_type", "Edge types");
+  params.addParamNamesToGroup("bottom_parameter left_parameter top_parameter right_parameter", "Edge parameter");
+  params.addParamNamesToGroup("nx ny bias_x bias_y", "Number and distribution of points");
+
   return params;
 }
 

test/tests/meshgenerators/transfinite_generator/discrete_generator.i

@@ -5,13 +5,15 @@
               10.0 -1.0 0.0
               11.0 5.0 0
               4.0 4.0 0'
-    nx = 8
-    ny = 5
+    nx = 10
+    ny = 7
     left_type = DISCRETE
     right_type = LINE
     top_type = CIRCARC
     bottom_type = LINE
     left_parameter = '-1.0 -1.0 0
+                      -0.7 -0.7 0.0
+                      -0.5 -0.5 0.0
                       0.0 0.0 0.0
                      0.75 0.75 0.0
                      2.5 2.5 0