[Paraview] Problem with custom time-aware reader

[Karl König]

Hi Ken,

> Everything looks like it is working fine to me.  It looks like you are
> getting the right time value in RequestData, you are finding the right
> time index, and you are setting the right time value in the output data.
> 
> The only thing wrong I see is that it is always printing out the
> filename for the last file.  But I don’t see anywhere in RequestData
> where you translated the time index to a file name.  At some point,
> probably in RequestInformation, FileName is set to the last file.  That
> never is overridden in RequestData.

So, essentially what you are suggesting is to create a mapping
timeStepValue -> FileName in RequestInformation and to set
this->FileName depending on the value of
outInfo->Get(vtkStreamingDemandDrivenPipeline::UPDATE_TIME_STEPS())[0]
in RequestData?

I didn't see anything like that happen in any of the other readers in
directory ParaView3/VTK/IO. So, I assumed some magic happening when
invoking
  output->GetInformation()->Set(
     vtkDataObject::DATA_TIME_STEPS(),
     &TimeStepValues[this->ActualTimeStep], 1);

After all, this->FileName gets automagically set before invoking
RequestInformation.

So, I have to set this->FileName manually? Actually, I tried that
already before posting. At the end of RequestData I set brutally

----- cut ---
  this->FileName = "file0.foo";
  std::cout << "RequestData: Got request for opening file <"
            << this->FileName << ">..."  << endl;
  this->UpdateProgress(1.0);
  return 1;
}
----- cut ---

That works, the correct file is opened, but it has the side effect of
segfaulting ParaView as soon as I disconnect from the server or delete
the reader object.
(Using the mapping timeStepValue -> FileName instead of hardcoding
FileName had the same effect.)

Karl


> On 9/3/09 9:19 AM, "Karl König" <kkoenig11 at web.de> wrote:
> 
>     Hi,
> 
>     I have a problem with a custom time-aware reader which I seem to cannot
>     work out on my own. I'm hoping someone on this list can shed some light
>     on the problem.
> 
>     The reader is designed following John's excellent tutorial
>     (http://www.paraview.org/Wiki/images/2/20/IEEE08_Time-In-ParaView.ppt)
>     and has been boiled down for this question to its essentials:
> 
>     Read in a sequence of plain ASCII text files, each of them containing
>     exactly one floating point value, nothing more. The values are
>     interpreted as time step values.
> 
>     The problem is that all files of the file series are inspected in method
>     RequestInformation, time information is displayed correctly in the
>     Information tab, I can walk through the files using VCR controls and
>     current data time step is properly increased/decreased. The problem,
>     though, is that for every time step the very same file - always the last
>     file of the file series - is loaded in RequestData.
> 
>     Here is the recipe to reproduce:
>     Unpack and compile the attached plugin in the usual manner using
>       mkdir build; cd build
>       cmake .. -DCMAKE_BUILD_TYPE=Release
>                -DParaView_DIR=/path/to/paraview/build/dir
>     and load it into ParaView 3.6.1 or 3.7-cvs.
> 
>     Create a sample input file series via:
>       for i in $(seq 0 9); do echo "0.${i}00" > file${i}.foo ; done
>     (there is already such a file series in the tarball)
> 
>     Open the collapsed file series "file..foo" in the file open dialog. On
>     standard output it will be shown that method RequestInformation is
>     called for all files of the sequence once, and an additional time for
>     the last file. (I probably could work around that by storing the name of
>     the last file being parsed and comparing it to the current file name.
>     But that's of minor interest.)
>     Click on the Apply button and walk through the files. On standard output
>     it will be reported that this->FileName does not change at all. I fail
>     to understand why. Am I missing some callback routine? According to my
>     understanding
> 
>     output->GetInformation()->Set(
>        vtkDataObject::DATA_TIME_STEPS(),
>        &TimeStepValues[this->ActualTimeStep], 1);
> 
>     in RequestData should do the magic, but it does not. Does anyone have an
>     idea?
> 
>     Thanks a lot in advance.
>     Karl
> 
> 
> 
>    ****      Kenneth Moreland
>     ***      Sandia National Laboratories
> ***********  
> *** *** ***  email: kmorel at sandia.gov
> **  ***  **  phone: (505) 844-8919
>     ***      web:   http://www.cs.unm.edu/~kmorel