No output

[Nils Holger Busch]

Hi,

I tried to write a reader for an image volume. The file contains the
whole
volume and the reader should build the vtk dataset from this single
file. It
should return or be convertible to a StructuredPoints dataset. Is
vtkImageReader still an appropriate base class ?
I put the file i/o in an overloaded UpdateInformation method and set the
scalar
data type and header size according to the header size of my file format
there.
Then the base class's UpdateInformation() is called. However, when
calling the
base class Initialize I receive the following error messages:

ERROR In vtkImageReader.cxx, line 537
vtkVISTAImageReader (0x1006a400): Initialize: Could not open file ÙP.v

Warning: In vtkImageReader.cxx, line 605
vtkVISTAImageReader (0x1006a400): File operation failed.

Generic Warning: In vtkImageReader.cxx, line 707
  File operation failed. row = 0, Read = 1, Skip0 = -2, Skip1 = 2,
FilePos = -1

It seems that after opening my data file and reading the information
there ,
the file name gets screwed up in the base class Initialize() and
OpenAndSeek
method. Is this a problem in the base class that tries to modify
InternalFileName?

I tried to get debugging information from the base class. It is a
trivial
question, but I could not find an answer in the source code or web page,
but
how do I turn on vtkDebug, so that vtkDebugMacro spits out its messages?

some time and trials later:

it seems that manually settin gthe InternalFileName to FileName confused
the methods in vtkImageReader.
I just open the my file with FileName in my UpdateInformation method and
I at least get no errors.
However, when running my app there is no output. My app is pretty much
the medical3 example except that I use my ImageReader and exclude the
vtkMarchingCubes for isosurface extraction. I just want to show three
slices of mi image data.

How do I proceed to find out where things go wrong in my vis pipeline?

I am rather clueless.

Thanks.

--
Best regards,
                                         Nils H. Busch

======================================================
=== Max-Planck-Institute of Cognitive Neuroscience ===
=== Phone:                     ++49 (341) 9940-234 ===
=== Fax:                       ++49 (341) 9940-221 ===
=== E-Mail:                       nilsb at cns.mpg.de ===
======================================================





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