0030008: BRepMesh does not respect angular deflection in internal area of bspline surface

1. Check whether the mesh satisfies the required angular deflection has been amended. Namely normals (to the surface) in the ends of any not "frontier" link are made collinear (with the given angular tolerance).

2. New parameters AngleInterior and DeflectionInterior have been added in IMeshTools_Parameters structure.

3. In case of thin long faces with internal edges, add points of internal edges to control parameters using grabParamsOfInternalEdges() in order to avoid aberrations on its ends. Disable addition of parameters from boundary edges in case of BSpline surface. Deviation can be controlled through the deflection parameter.

4. Grab parameters from edges in case if there is just a single interval on BSpline surface along U and V direction.

src/MeshTest/MeshTest.cxx

@@ -118,8 +118,11 @@ static Standard_Integer incrementalmesh(Draw_Interpretor& di, Standard_Integer n
 Builds triangular mesh for the shape\n\
 usage: incmesh Shape LinearDeflection [options]\n\
 options:\n\
-        -a val          angular deflection in deg\n\
+        -a val          angular deflection for edges in deg\n\
                         (default ~28.64 deg = 0.5 rad)\n\n\
+        -ai val         angular deflection inside of faces in deg\n\
+                        (default ~57.29 deg = 1 rad)\n\n\
+        -di val         Linear deflection used to tessellate the face interior.\n\
         -min            minimum size parameter limiting size of triangle's\n\
                         edges to prevent sinking into amplification in case\n\
                         of distorted curves and surfaces\n\n\
@@ -142,6 +145,8 @@ options:\n\
   }
 
   IMeshTools_Parameters aMeshParams;
+  aMeshParams.Deflection = aMeshParams.DeflectionInterior = 
+    Max(Draw::Atof(argv[2]), Precision::Confusion());
 
   if (nbarg > 3)
   {
@@ -168,8 +173,16 @@ options:\n\
         {
           aMeshParams.Angle = aVal * M_PI / 180.;
         }
+        else if (aOpt == "-ai")
+        {
+          aMeshParams.AngleInterior = aVal * M_PI / 180.;
+        }
         else if (aOpt == "-min")
           aMeshParams.MinSize = aVal;
+        else if (aOpt == "-di")
+        {
+          aMeshParams.DeflectionInterior = aVal;
+        }
         else
           --i;
       }