[Paraview] Problem with Custom ParaView Reader

[Kalin Kanov]

Hi Andy,

Thank you for taking a close look at this and for the comments. That 
seems to have been indeed the issue.

Best,
Kalin


On 12.2.2014 г. 14:40, Andy Bauer wrote:
> Hi Kalin,
>
> I think the issue is that your extents are wrong. The extents should be
> the index of the first and last point in each logical direction so it
> should be [0, 15, 0, 15, 0, 15] if you have a square grid with 4096
> points. Note that this is the whole extent that the reader could provide
> even though subsequent filters may ask for a reduced extent. Also, in
> RequestData() you should get the requested extent with something like
> the following and take out the SetDimension() call:
>
>    vtkInformation *outInfo = outputVector->GetInformationObject(outputPort);
>    int subext[6];
>    outInfo->Get(vtkStreamingDemandDrivenPipeline::UPDATE_EXTENT(),subext);
>    image->SetExtent(subext);
>
> Then use the subextent to fill in your scalars array since it may be
> less than what it could potentially provide (e.g. why read in all data
> when you only need a subset of that).
>
> I've filled in the vtkJHTDBReader.cxx code with some comments and
> changes. You should go through and review what I did since I can't test
> your code.
>
> Regards,
> Andy
>
>
>
> On Wed, Feb 12, 2014 at 1:47 PM, Kalin Kanov <kalin at cs.jhu.edu
> <mailto:kalin at cs.jhu.edu>> wrote:
>
>     Hi Andy,
>
>     Thanks for the quick response. I am setting the extent to be
>     [0,16,0,16,0,16], as follows:
>
>     in the constructor:
>              this->extent[0] = 0;
>              this->extent[1] = 16;
>              this->extent[2] = 0;
>              this->extent[3] = 16;
>              this->extent[4] = 0;
>              this->extent[5] = 16;
>
>     in RequestInformation():
>              outInfo->Set(
>                      vtkStreamingDemandDrivenPipeli__ne::
>                      WHOLE_EXTENT(),
>                      this->extent, 6);
>
>     Attached is the .vti file and the code. In the test harness I also
>     have a vtkRenderer, which also displays the data as a 3d cube.
>
>
>
>
>     On 12.2.2014 г. 13:30, Andy Bauer wrote:
>
>         Hi Kalin,
>
>         I'm thinking that maybe there is ghost level information that is
>         wrong,
>         or maybe extent information. I'm assuming that you're running
>         the server
>         in serial so in that case you shouldn't have any ghost levels.
>         If your
>         grid has 16 points in each direction than than the extent for that
>         should be [i, i+15, j, j+15, k, k+15] for a single process (note
>         that
>         extents don't need to start from 0 but usually do). If your grid
>         is 16
>         cells in each direction than the extent would be [i, i+16, j,
>         j+16, k,
>         k+16].
>
>         If that isn't the problem, dan you share your code and your vti file
>         from your test harness?
>
>         Regards,
>         Andy
>
>
>         On Wed, Feb 12, 2014 at 1:11 PM, Kalin Kanov <kalin at cs.jhu.edu
>         <mailto:kalin at cs.jhu.edu>
>         <mailto:kalin at cs.jhu.edu <mailto:kalin at cs.jhu.edu>>> wrote:
>
>              Dear All,
>
>              I am developing a custom ParaView reader for my data. I have a
>              working plugin for ParaView that reads and displays the data.
>              However, what I am getting in the 3D view is not as
>         expected. My
>              reader subclasses vtkImageAlgorithm and produces a 3D
>         structured
>              grid. When I load the data in ParaView I only see 3 of the
>         surfaces
>              of the cube (attached is a screenshot). Any idea why this
>         would be
>              happening?
>
>              When I view the data in spreadsheet form all 4096 point
>         (the testing
>              cube is 16x16x16) have associated scalar data and the
>         coordinates
>              look good, but the 3D view displays only the left, right
>         and bottom
>              walls of the cube. Additionally, I also have a small test
>         harness
>              that uses my custom reader as input for a
>         vtkXMLImageDataWriter and
>              the resulting .vti file when loaded into ParaView and
>         visualized
>              looks good.
>
>              Thank you,
>              Kalin Kanov
>
>
>
>