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--></style></head><body lang="EN-US" link="blue" vlink="purple"><div class="WordSection1"><p class="MsoNormal"><a name="_MailEndCompose"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Unfortunately this is a real issue and the fix is sort of ugly/painful unless I am missing something. The issue is that the new backend converts quads/polygons into triangles as quads and polygons are deprecated in later versions of OpenGL. Plus triangles are fast as they each have just 3 verts and can be counted on to have three verts etc. :-) But when you render wireframe you do not want to use the same IBO because if your original data was a quad, showing triangle wireframes would be misleading. So we build a different IBO that constructs the boundary edges as lines. Lines do not get front/back culled by OpenGL. The reason we do not use triangle_fans is that without the primitive restart index support (not available in OpenGL 2.1 or ES 2.0/3.0/3.1) you (or the driver) have to essentially make a draw call per primitive which is slow. Plus glPolygonMode is not in OpenGL ES so it would not work on iOS/Android anyhow. So ... edge visibility or wireframe when combined with front/back culling is not working and off the top of my head I cannot think of a universal solution other than performing the culling on the CPU and sending a new IBO up every frame, yuck.</span></a></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Ken</span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Ken Martin PhD</span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Chairman & CFO</span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Kitware Inc.</span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">28 Corporate Drive</span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Clifton Park NY 12065</span></p><p class="MsoNormal"><a href="mailto:ken.martin@kitware.com"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">ken.martin@kitware.com</span></a><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">919 869-8871 (w)</span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">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.</span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Paraview-developers [mailto:<a href="mailto:paraview-developers-bounces@paraview.org">paraview-developers-bounces@paraview.org</a>] <b>On Behalf Of </b>Joachim Pouderoux<br><b>Sent:</b> Friday, September 11, 2015 5:52 AM<br><b>To:</b> Felipe Bordeu<br><b>Cc:</b> ParaView Developers<br><b>Subject:</b> Re: [Paraview-developers] Backface Styling bug?</span></p><p class="MsoNormal"> </p><div><div><div><p class="MsoNormal" style="margin-bottom:12.0pt">Not totally sure but it could be related to Ken's current merge request: <a href="https://gitlab.kitware.com/vtk/vtk/merge_requests/643">https://gitlab.kitware.com/vtk/vtk/merge_requests/643</a></p></div><p class="MsoNormal" style="margin-bottom:12.0pt">Support of OpenGL2 backend in PV is not yet complete by the way. PV4.4 is still base on the legacy backend.</p></div><div><p class="MsoNormal">Regards,</p></div><div><p class="MsoNormal"> </p></div></div><div><p class="MsoNormal"><br clear="all"></p><div><div><div><p class="MsoNormal"><b>Joachim Pouderoux</b></p><p class="MsoNormal"><i><span style="font-size:7.5pt">PhD, Technical Expert</span></i><br><b><span style="font-size:7.5pt"><a href="http://www.kitware.fr" target="_blank">Kitware SAS</a></span></b></p></div></div></div><p class="MsoNormal"> </p><div><p class="MsoNormal">2015-09-11 11:24 GMT+02:00 Felipe Bordeu <<a href="mailto:felipe.bordeu@ec-nantes.fr" target="_blank">felipe.bordeu@ec-nantes.fr</a>>:</p><p class="MsoNormal"><br>-----BEGIN PGP SIGNED MESSAGE-----<br>Hash: SHA1<br><br>hi I don't know if this is a bug of paraview or vtk.<br><br>1) make a simple Arrow source<br>2) change the view to Surface With Edges.<br>3) change the "Backface Representation" to "Cull Frontface"<br><br>only the back surfaces are rendered (as expected ), but ALL the edge are<br>rendered.<br><br>Using the 4.4.0-RC2 64bit on linux and using "<br>VTK_RENDERING_BACKEND OpenGL2"<br><br>In Paraview 4.3.1 (binary from web) only the back edges and surface are<br>rendered (as expected).<br><br>Felipe<br><br><br><br>- --<br>Felipe Bordeu Weldt<br>Ingénieur de Recherche<br>- -------------------------------------<br>Tél. : 33 (0)2 40 37 16 57<br>Fax. : 33 (0)2 40 74 74 06<br><a href="mailto:Felipe.Bordeu@ec-nantes.fr">Felipe.Bordeu@ec-nantes.fr</a><br>Institut GeM - UMR CNRS 6183<br>École Centrale Nantes<br>1 Rue de La Noë, 44321 Nantes, FRANCE<br>- -------------------------------------<br>-----BEGIN PGP SIGNATURE-----<br>Version: GnuPG v2.0.22 (GNU/Linux)<br><br>iQEcBAEBAgAGBQJV8p2xAAoJEE/fMfNgU9/DvLoH/3JFey952hrOasLRGru21uDk<br>5N2Eo5kTufU6kuscgplro2Ph2GAuxil5gxbBGk9Cze4WvE5KCGTetwrLAr9ZQRMJ<br>ps8KcXRYL0qC+EKXf7bfwSNLyuBmRRlhLOes0UKk1rP8CMk9JWxeSIq3xBQljxSJ<br>kFtlTDQwuzff2UFxvWcNd8c+6dKTqX1beSVwCxjNaFo3jQYAsXGZJ2BsstruLCvU<br>85AkrRlEhiWf4C5XyIKUhp2b3IjzeNW63YZGobEveyBOzlcQIrtR8QQefI5gOObq<br>Xh1fiHntimZyfXYsK88x8eY9JFSOovTvJ8Q0K9Dba0U+8MHEdrYkZuNUBAYnbOE=<br>=R9E6<br>-----END PGP SIGNATURE-----<br><br><br>_______________________________________________<br>Powered by <a href="http://www.kitware.com" target="_blank">www.kitware.com</a><br><br>Visit other Kitware open-source projects at <a href="http://www.kitware.com/opensource/opensource.html" target="_blank">http://www.kitware.com/opensource/opensource.html</a><br><br>Search the list archives at: <a href="http://markmail.org/search/?q=Paraview-developers" target="_blank">http://markmail.org/search/?q=Paraview-developers</a><br><br>Follow this link to subscribe/unsubscribe:<br><a href="http://public.kitware.com/mailman/listinfo/paraview-developers" target="_blank">http://public.kitware.com/mailman/listinfo/paraview-developers</a></p></div><p class="MsoNormal"> </p></div></div></body></html>