[Paraview-developers] suspicious behaviour with structured Grids (in partuicular)

[Biddiscombe, John A.]

David

>Was volume rendering involved?

Not involved. The visual errors appear when drawing just a surface representation.

I tried a large run on a 64 pvserver job yesterday using the new imagedata version of the resampler, after the resampling completed, pvservers shut down as before and I lost connection. I am trying to debug it on the cluster today but my parallel debugging skills on linux are sadly quite poor.

JB


David E DeMarle
Kitware, Inc.
R&D Engineer
21 Corporate Drive
Clifton Park, NY 12065-8662
Phone: 518-881-4909



On Thu, Sep 1, 2011 at 2:32 AM, Biddiscombe, John A. <biddisco at cscs.ch> wrote:
> I've had a lot of problems with a particular set of filters of mine which resample SPH data onto grids.
>
> I have a Grid Generator class which is used as the sample location. This class outputs a vtkStructuredGrid.
> When running in Parallel, I see very odd behaviour - which appears similar to a post I saw some months ago but can't find now, where the data displayed appears to be incorrect. Almsot as though the data from process 0 is being drawn on all processes and something is just not right, but I can't quite pin it down.
>
> Because I have custom extent translators, dodgy extent manipulations and all parallel features, I can never be quite sure that it's paraview that's fundamentally broken or my stuff.
>
> However, in the case where the resampling grid is regular and axis aligned, the output could be vtkImageData, which I believe does work quite well in parallel, so I made a new stripped down resampler which outputs only image data. This works fine. The extent translation/manipulation is the same, the resampling the same, everything the same, except it produces image data.
>
> This one doesn't crash or misbehave when run in parallel, however the image looks wrong 'first time' it is done, if I delete the filter, recreate a second one and then reexecute using identical settings, I get a completely different image and it looks perfect.
>
> I really don't understand what is going on, but my feeling now is that paraview is broken somewhere deep inside (and is essentially unfit for purpose)
>
> The problem is slightly less bad on 3.11 than on 3.10, but I still don't know what is actually wrong. I still don't know if I've messed up, or if ParaView is messing me up. (I have a complicated scenario where a multi-input filter passes update extent information from the second input).
>
> I'm only posting this because I have some vague memory that someone else reported duplicated colours from process 0 on some gridded data in parallel and it's just possible, I'm seeing aspects of the same bug. I can't file a proper bug report because I'm still not completely sure a bug really exists. I'm just hoping someone reading this might mention something which triggers other thoughts, comments etc.
>
> yours
>
> JB
>
>
> --
> John Biddiscombe,                            email:biddisco @ cscs.ch
> http://www.cscs.ch/
> CSCS, Swiss National Supercomputing Centre  | Tel:  +41 (91) 610.82.07
> Via Cantonale, 6928 Manno, Switzerland      | Fax:  +41 (91) 610.82.82
>
>
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