ENH: extrudeMesh: make edge collape optional

applications/utilities/mesh/generation/extrude/extrudeMesh/extrudeMesh.C

@@ -238,6 +238,25 @@ int main(int argc, char *argv[])
         dict.lookup("constructFrom")
     );
 
+    // Any merging of small edges
+    const scalar mergeTol(dict.lookupOrDefault<scalar>("mergeTol", 1e-4));
+
+    Info<< "Extruding from " << ExtrudeModeNames[mode]
+        << " using model " << model().type() << endl;
+    if (flipNormals)
+    {
+        Info<< "Flipping normals before extruding" << endl;
+    }
+    if (mergeTol > 0)
+    {
+        Info<< "Collapsing edges < " << mergeTol << " of bounding box" << endl;
+    }
+    else
+    {
+        Info<< "Not collapsing any edges after extrusion" << endl;
+    }
+    Info<< endl;
+
 
     // Generated mesh (one of either)
     autoPtr<fvMesh> meshFromMesh;
@@ -715,7 +734,7 @@ int main(int argc, char *argv[])
 
     const boundBox& bb = mesh.bounds();
     const vector span = bb.span();
-    const scalar mergeDim = 1e-4 * bb.minDim();
+    const scalar mergeDim = mergeTol * bb.minDim();
 
     Info<< "Mesh bounding box : " << bb << nl
         << "        with span : " << span << nl
@@ -726,6 +745,7 @@ int main(int argc, char *argv[])
     // Collapse edges
     // ~~~~~~~~~~~~~~
 
+    if (mergeDim > 0)
     {
         Info<< "Collapsing edges < " << mergeDim << " ..." << nl << endl;
 

applications/utilities/mesh/generation/extrude/extrudeMesh/extrudeMeshDict

@@ -88,4 +88,8 @@ sigmaRadialCoeffs
 // degree wedges.
 mergeFaces false;   //true;
 
+// Merge small edges. Fraction of bounding box.
+mergeTol 0;
+
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

tutorials/incompressible/pimpleDyMFoam/wingMotion/wingMotion2D_simpleFoam/system/extrudeMeshDict

@@ -10,12 +10,14 @@ FoamFile
     version     2.0;
     format      ascii;
     class       dictionary;
-    object      extrudeProperties;
+    object      extrudeMeshDict;
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 // What to extrude:
 //      patch   : from patch of another case ('sourceCase')
+//      mesh    : as above but with original case included
+//      surface : from externally read surface
 
 constructFrom patch;
 sourceCase "../wingMotion_snappyHexMesh";
@@ -24,7 +26,8 @@ sourcePatches (front);
 // If construct from patch: patch to use for back (can be same as sourcePatch)
 exposedPatchName back;
 
-// Flip surface normals before usage.
+// Flip surface normals before usage. Valid only for extrude from surface or
+// patch.
 flipNormals false;
 
 //- Linear extrusion in point-normal direction
@@ -41,7 +44,10 @@ linearNormalCoeffs
 
 // Do front and back need to be merged? Usually only makes sense for 360
 // degree wedges.
-mergeFaces false;
+mergeFaces false;   //true;
+
+// Merge small edges. Fraction of bounding box.
+mergeTol 0;
 
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //