trust object type and avoid dynamic_cast due to cross-library RTTI trouble.

ObjectTypes/PolyhedralMesh/PluginFunctionsPolyhedralMesh.cc

@@ -108,7 +108,7 @@ bool getObject( int _identifier, PolyhedralMeshObject*& _object ) {
   BaseObjectData* object = 0;
   PluginFunctions::getObject(_identifier,object);
 
-  _object = dynamic_cast< PolyhedralMeshObject* >(object);
+  _object = polyhedralMeshObject(object);
   return ( _object != 0 );
 }
 
@@ -120,7 +120,7 @@ bool getObject( int _identifier, PolyhedralMeshObject*& _object ) {
 PolyhedralMesh* polyhedralMesh( BaseObjectData* _object ) {
 
   if ( _object->dataType(DATA_POLYHEDRAL_MESH) ) {
-    PolyhedralMeshObject* object = dynamic_cast< PolyhedralMeshObject* >(_object);
+    PolyhedralMeshObject* object = static_cast< PolyhedralMeshObject* >(_object);
     return object->mesh();
   } else
     return 0;
@@ -139,7 +139,7 @@ PolyhedralMesh* polyhedralMesh( int _identifier ) {
 PolyhedralMeshObject* polyhedralMeshObject( BaseObjectData* _object ) {
   if ( ! _object->dataType(DATA_POLYHEDRAL_MESH) )
     return 0;
-  return dynamic_cast< PolyhedralMeshObject* >( _object );
+  return static_cast< PolyhedralMeshObject* >( _object );
 }