Dear Utkarsh, Thanks a lot for your answer. The type of my data is "Rectilinear Grid" (turbulence data on a regular grid). The test case that I use to reproduce the data leads to a size of the contours (from the statistics inspector) 230316 cells, and a memory of 15 MB. I have turned off all the remote render thresholds etc. and the problem persists. Thus it is likely that it is the contour filter that causes the miscolouring.
I have just reroduced the problem using the latest version 3.10.1 (Linux 32-bit); and I generated a screenshot on http://www.mech.kth.se/~pschlatt/files/Screenshot.png. The test is simple; I read in a rectilinear grid with a few velocity components. Then I compute a new scalar field, essentially being the x-corrdinate. Then I plot an isocontour, and colour it with the result of the calculator. I would expect a continuous colour going from blue to red spread over the whole x extent, however - according to the number of processors used (in that case 16) - I get a repetitive pattern. By some more experimenting it becomes clear that for some reason the colouring is done based on the scalar value on the first processor only. Running on 1 processor everything is fine. I am of course happy to provide the respective data files, if this could help. Thanks for any help! Best regards, Philipp -----Original Message----- From: Utkarsh Ayachit [mailto:utkarsh.ayac...@kitware.com] Sent: den 20 juni 2011 16:59 To: Philipp Schlatter Cc: paraview@paraview.org Subject: Re: [Paraview] FW: Coloured isosurfaces when running MPI That's very peculiar. What datatype are you contouring? (With the reader selected in the pipeline browser, go to the information tab, what does the "Type" field say?) Also after generating the iso-surface, open the statistics inspector (View | Statistics Inspector). What is the size of the geometry generated from the contour filter. If that's not too large, you try doing local-rendering (go to Edit | Settings, on the Server page, uncheck Remote Render Threshold). Does that help? This will help diagnose if the issue is with rendering or with the data generated by the contour filter itself. Utkarsh On Sun, Jun 19, 2011 at 11:25 AM, Philipp Schlatter <pschl...@mech.kth.se> wrote: > Dear forum, > > I am using Paraview to visualise a large dataset coming from a direct > simulation of turbulence (size of the original data of order 10-100GB). > Naturally, I am running in parallel on a cluster (using the mesa), > which also works very well. > > However, there is one issue: I want to visualise isosurfaces of a > quantity, and colour them using another scalar quantity. When running > serial, everything is fine. When using multiple processors with MPI > leading to the data being distributed, the rendering of the isosurfaces is still ok. > However, the colouring seems to be based on the scalar field of the > first data segment (i.e. the first processor) only. This then leads to > very visible boundaries between the processors as the colours are > clearly not correct (see example on > http://www.mech.kth.se/~pschlatt/files/resampled.jpg). Again, running > on a single processor everything is correct, and running on different > numbers of processors will shift the edges. > > This issue could be confirmed in all version up to 3.10. > > Due to this, I am required to run in serial, which is very painful > both due to memory requirements and very long rendering times (up to > 15 minutes for a single frame). Thus, if there would be a simple fix, I'd be very interested. > > Thanks a lot in advance for any hint. > Best regards, > Philipp Schlatter > KTH Mechanics, Stockholm, Sweden > > _______________________________________________ > Powered by www.kitware.com > > Visit other Kitware open-source projects at > http://www.kitware.com/opensource/opensource.html > > Please keep messages on-topic and check the ParaView Wiki at: > http://paraview.org/Wiki/ParaView > > Follow this link to subscribe/unsubscribe: > http://www.paraview.org/mailman/listinfo/paraview > _______________________________________________ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the ParaView Wiki at: http://paraview.org/Wiki/ParaView Follow this link to subscribe/unsubscribe: http://www.paraview.org/mailman/listinfo/paraview