viewFactorsGen: Handle baffles

Resolves bug-report http://www.openfoam.org/mantisbt/view.php?id=1680

applications/utilities/preProcessing/viewFactorsGen/viewFactorsGen.C

@@ -69,6 +69,7 @@ Description
 
 using namespace Foam;
 
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 triSurface triangulate
 (
@@ -208,6 +209,9 @@ scalar calculateViewFactorFij
 {
     vector r = i - j;
     scalar rMag = mag(r);
+
+    if (rMag > SMALL)
+    {
         scalar dAiMag = mag(dAi);
         scalar dAjMag = mag(dAj);
 
@@ -222,6 +226,11 @@ scalar calculateViewFactorFij
             /(sqr(rMag)*constant::mathematical::pi)
         );
     }
+    else
+    {
+        return 0;
+    }
+}
 
 
 void insertMatrixElements