[vtk-developers] Bug in vtkCompositeDataPipeline?

[Bill McGrory]

I've been trying to get a
vtkMultiBlockDataSet to work properly with vtkStructuredGrid's which are
output from a vtkStructuredGridSource

>From what I can tell, it appears that the the  vtkCompositeDataPipeline
is unaware of child vtkDataObject->Source, so none of the data ever gets
loaded.

I have constructed a work-around which appears (superficially at least)
to work for my particular case, which is basically, if a Source exists
for the original vtkDataObject in the *ForBlock() routines, call the
relevant Update's before performing the ShallowCopy

patch is as follows

Index: vtkCompositeDataPipeline.cxx
===================================================================
RCS file: /cvsroot/VTK/VTK/Filtering/vtkCompositeDataPipeline.cxx,v
retrieving revision 1.34
diff -u -r1.34 vtkCompositeDataPipeline.cxx
--- vtkCompositeDataPipeline.cxx	7 Dec 2005 16:21:29 -0000	1.34
+++ vtkCompositeDataPipeline.cxx	25 May 2006 19:48:48 -0000
@@ -35,6 +35,8 @@
 #include "vtkStructuredGrid.h"
 #include "vtkUniformGrid.h"
 
+#include "vtkSource.h"
+
 vtkCxxRevisionMacro(vtkCompositeDataPipeline, "$Revision: 1.34 $");
 vtkStandardNewMacro(vtkCompositeDataPipeline);
 
@@ -46,6 +48,28 @@

vtkInformationKeyMacro(vtkCompositeDataPipeline,INPUT_REQUIRED_COMPOSITE_DATA_TYPE, String);
 vtkInformationKeyMacro(vtkCompositeDataPipeline,UPDATE_BLOCKS,
ObjectBase);
 
+class vtkCompositeDataPipelineToDataObjectFriendship
+{
+public:
+  static void UpdateDataObject(vtkDataObject* obj)
+    {
+		if(obj->Source)
+		{
+			obj->Source->Update();
+		}
+		
+    }
+
+  static void UpdateInformation(vtkDataObject* obj)
+    {
+		if(obj->Source)
+		{
+			obj->Source->UpdateInformation();
+		}
+		
+    }
+};
+
 //----------------------------------------------------------------------------
 vtkCompositeDataPipeline::vtkCompositeDataPipeline()
 {
@@ -490,6 +514,7 @@
         info->Get(vtkDataObject::DATA_OBJECT());
       if (dobj && dobjCopy)
         {
+
vtkCompositeDataPipelineToDataObjectFriendship::UpdateInformation(dobj);
         dobjCopy->ShallowCopy(dobj);
         dobjCopy->CopyInformation(dobj);
         }
@@ -1089,6 +1114,7 @@
         
         if (dobj && dobjCopy)
           {
+
vtkCompositeDataPipelineToDataObjectFriendship::UpdateDataObject(dobj);
           dobjCopy->ShallowCopy(dobj);
           }
         }


Is this really a bug, and is this an appropriate fix?
Or am I doing something wrong up the pipeline, such that I shouldn't
need to do this?

Regards
Bill
-- 
Dr. William D. McGrory    AeroSoft, Inc.
mcgrory at aerosft.com       Suite 1275
(540) 557-1904            1872 Pratt Drive
(540) 557-1919 (FAX)      Blacksburg, VA 24060