[Paraview] Error in MultiBlockPLOT3DReader

[Berk Geveci]

You are absolutely right. I have been working on the plot3d reader for
some other project and discovered the same issue. Once I am done with
my changes, I will incorporate them back to the paraview repository.
It may not make into a 3.2 patch release but should make into the 3.4
release. I am also working on plot3d file series (for time support)
and reading (multi-block) plot3d files in parallel.

-berk

On 12/19/07, Richard GRENON <richard.grenon at onera.fr> wrote:
> Hello,
>
> I discovered Paraview 3.2.1 recently, Nice software.
>
> I am using the MultibockPLOT3DReader for my data and I have found an
> error when reading Fortran Unformatted Plot3D files, that is reading
> with the options "Binary File", "Multi Grid" and "Has Byte Count" set
> on: when reading MultiGrid files with 5 grids, I have found that
> Paraview computed wrong min and max values of density, momentum
> components and stagnation energy. In particular, the min value of
> density was set to zero, athough I knew it should be 0.5857 for my data,
> and computing other Plot3d functions failed.
>
> My Fortran Unformatted PLOT3D files were tested without problem in
> Fieldview, so I don't think they are corrupted. And also, I have
> verified with a C program that the true min and max values were not the
> values computed by Paraview. But all became OK in Paraview after I
> converted my data in pure Binary files without Byte Count, so the
> problem in Paraview is really when reading Fortran Unformatted PLOT3D
> files that require "Binary File", "Multi Grid" and "Has Byte Count" to
> be set on together.
>
> I looked at the source and I have found that the MultiBlockPLOT3DReader
> skips the four leading "Byte Count" bytes before reading all density,
> momentum and stagnation energy values in a single record, but it does
> not skip again the trailing "Byte Count" bytes after reading the data
> record as it should do! That does not matter if you have a single grid
> file, but when you have several grids, data are shifted in the arrays
> each you read a new grid. The problems is only when reading the "q" file
> in the loop on i from 0 to numBlocks starting at line 943 in the file
> "vtkMultiBlockPLOT3DReader.cxx". I think that you should add
> "this->SkipByteCount(qFp)" at the end of the loop just after line 1059.
>
> I hope that developers can check if I am right, and maybe include the
> corrected reader in a future Paraview release?
>
> Best regards.
>
> --
>  Richard GRENON
>  ONERA
>  Departement d'Aerodynamique Appliquee - DAAP/ACI
>  8 rue des Vertugadins
>  92190 MEUDON - FRANCE
>  phone : +33 1 46 73 42 17
>  fax   : +33 1 46 73 41 46
>  mailto:Richard.Grenon at onera.fr
>  http://www.onera.fr
>
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