[Paraview] Polyhedral Cells: Rendering Problem with OpenGL...

Joachim Pouderoux joachim.pouderoux at kitware.com
Mon Oct 31 08:54:52 EDT 2016


Surprisingly I have not been able to reproduce the issue with ParaView
5.2rc2/OpenGL2.
For the Slice filter, the "Triangulate the slice" option is turned ON by
default.
Then ParaView polygonal data representation has a "Triangulate" advanced
option that is turned OFF by default but you could need if data is not
triangulated.

J.

*Joachim Pouderoux*, PhD

*Technical Expert - Scientific Computing Team*
*Kitware SAS <http://www.kitware.fr>*


2016-10-26 9:23 GMT-04:00 Ken Martin <ken.martin at kitware.com>:

> Basically it is OpenGL, in that OpenGL doesn't automatically tessellate
> concave polygons. Making VTK always examine every polygon to determine if
> it is  concave would be a performance hit for everyone, so we leave it up
> to developers to use a triangle filter if they need it.
>
> Thanks
> Ken
>
> On Tue, Oct 18, 2016 at 9:11 AM, Stefan Melber <Stefan.Melber at dlr.de>
> wrote:
>
>> Hi Martin,
>>
>> i tried the triangle filter in all cases - and yes - i works in all three
>> cases.
>>
>> So is this "problem" of concave polygons inside VTK or in OpenGL?
>>
>> Best regards,
>>
>>       Stefan
>>
>> I'm not sure if this is your issue, but you might try using a triangle
>> filter on your data. For OpenGL we do not guarantee correct rendering of
>> concave polygons. The triangle filter will convert a concave polygon into
>> convex triangles which should render correctly.
>>
>> On Tue, Oct 18, 2016 at 2:20 AM, Stefan Melber <Stefan.Melber at dlr.de>
>> wrote:
>>
>>> Hi,
>>>
>>> i found a rendering problem with cuts through polyhedral cells depending
>>> on which rendering backend is used. For example in PV 5.1.2 compiled with
>>>
>>> VTK_RENDERING_BACKEND = OpenGL
>>>
>>> a cut looks like error.opengl.v5_1_2.png - there is a wrong shading and
>>> some facets coming from the wrong starting point.
>>>
>>> Switching to OpenGL2 everything is fine (error.opengl2.v5_1_2.png). This
>>> problem is the same with ParaView 5.2.0RC1 and OpenGL or OpenGL2 - however
>>> there seems to be an additional (smaller) problem using OpenGL2: there are
>>> some lines drawn outside of the shell - see error.opengl2.v5_2_0rc1.png
>>> (cutted on a different position).
>>>
>>> The example cell is for testing is attached as "error.vtk" - cut e.g. in
>>> x-direction on different positions to get the described effects.
>>>
>>> Best regards,
>>>
>>>        Stefan
>>>
>>>
>>> System:
>>> o OpenSuse Tumbleweed
>>> o Kernel: 4.7.6-1
>>> o Linux 64 bit
>>> o NVidia Quadro 4000 / NV Driver v367.44
>>>
>>>
>>>
>>> ================================================================
>>>
>>>                      _/             *Dr. Stefan Melber-Wilkending*
>>>                    _/_/
>>>                  _/  _/             Deutsches Zentrum für Luft-
>>>          _/_/_/_/_/_/_/_/_/_/         und Raumfahrt e.V. (DLR)
>>>        _/    _/    _/    _/
>>>      _/    _/    _/    _/             German Aerospace Center
>>>    _/_/_/_/_/_/_/_/_/_/              Institute of Aerodynamics
>>>          _/  _/  _      _               and Flow Technology
>>>          _/_/   | \ |  |_|           Transport Aircraft Branch
>>>          _/     |_/ |_ | \
>>>                                          Lilienthalplatz 7
>>>  Fields of activities:                  38108 Braunschweig
>>>                                              Germany
>>>  o Numerical Windtunnel Simulation
>>>  o Aero-Acoustic Windtunnel Design    Phone : +49 531/295-2836
>>>  o Numerical Optimization             Fax. .: +49 531/295-2914
>>>  o Visualization Techniques
>>>  o High-Lift Aerodynamics           Email : Stefan.Melber at DLR.de
>>>  o Glider-Aerodynamics              Web ..: http://www.dlr.de/AS
>>>
>>>
>>> ================================================================
>>>
>>>
>>> _______________________________________________
>>> 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
>>>
>>> Search the list archives at: http://markmail.org/search/?q=ParaView
>>>
>>> Follow this link to subscribe/unsubscribe:
>>> http://public.kitware.com/mailman/listinfo/paraview
>>>
>>>
>>
>>
>> --
>> Ken Martin PhD
>> Chairman & CFO
>> Kitware Inc.
>> 28 Corporate Drive
>> Clifton Park NY 12065
>> 518 371 3971
>>
>> This communication, including all attachments, contains confidential and
>> legally privileged information, and it is intended only for the use of the
>> addressee.  Access to this email by anyone else is unauthorized. If you are
>> not the intended recipient, any disclosure, copying, distribution or any
>> action taken in reliance on it is prohibited and may be unlawful. If you
>> received this communication in error please notify us immediately and
>> destroy the original message.  Thank you.
>>
>>
>>
>
>
> --
> Ken Martin PhD
> Chairman & CFO
> Kitware Inc.
> 28 Corporate Drive
> Clifton Park NY 12065
> 518 371 3971
>
> This communication, including all attachments, contains confidential and
> legally privileged information, and it is intended only for the use of the
> addressee.  Access to this email by anyone else is unauthorized. If you are
> not the intended recipient, any disclosure, copying, distribution or any
> action taken in reliance on it is prohibited and may be unlawful. If you
> received this communication in error please notify us immediately and
> destroy the original message.  Thank you.
>
> _______________________________________________
> 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
>
> Search the list archives at: http://markmail.org/search/?q=ParaView
>
> Follow this link to subscribe/unsubscribe:
> http://public.kitware.com/mailman/listinfo/paraview
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://public.kitware.com/pipermail/paraview/attachments/20161031/9b0dd56e/attachment.html>


More information about the ParaView mailing list