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<TITLE>Re: [Paraview] Off Screen Rendering</TITLE>
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<FONT FACE="Calibri, Verdana, Helvetica, Arial"><SPAN STYLE='font-size:11pt'>That is correct with two clarifications:<BR>
<BR>
The “with —use-offscreen-rendering” explanation is only correct for when ParaView is compiled with OSMesa.<BR>
<BR>
The “without —use-offscreen-rendering” behavior only happens because the servers try to open X windows and fail.<BR>
<BR>
-Ken<BR>
<BR>
<BR>
On 11/25/09 11:50 PM, "chew ping" <<a href="lcp81um@msn.com">lcp81um@msn.com</a>> wrote:<BR>
<BR>
</SPAN></FONT><BLOCKQUOTE><FONT SIZE="2"><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:10pt'> <BR>
Dear all,<BR>
<BR>
so based on the timer log results that i collected, what i read about offscreen-rendering and the explanation below, can i conclude the followings? someone pls correct me if i'm wrong!<BR>
<BR>
with --use-offscreen-rendering<BR>
</SPAN></FONT></FONT><UL><LI><FONT SIZE="2"><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:10pt'>X windows are disabled on all server processes
</SPAN></FONT></FONT><LI><FONT SIZE="2"><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:10pt'>all server processes render the geometry locally
</SPAN></FONT></FONT><LI><FONT SIZE="2"><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:10pt'>then each server processes sends the image to the client for compositing
</SPAN></FONT></FONT><LI><FONT SIZE="2"><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:10pt'>there's NO data gathering to process 0, meaning the master doesn't collect all images from each processes for composting, then only send it to the client for rendering
</SPAN></FONT></FONT><LI><FONT SIZE="2"><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:10pt'>that's why --use-offscreen-rendering is faster<BR>
</SPAN></FONT></FONT></UL><FONT SIZE="2"><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:10pt'> <BR>
<BR>
without --use-offscreen-rendering<BR>
</SPAN></FONT></FONT><UL><LI><FONT SIZE="2"><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:10pt'>X windows are enabled on all server processes
</SPAN></FONT></FONT><LI><FONT SIZE="2"><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:10pt'>all server processes the raw data, then send all geometry to process 0
</SPAN></FONT></FONT><LI><FONT SIZE="2"><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:10pt'>process 0 gather all geometry then send them to the client to render
</SPAN></FONT></FONT><LI><FONT SIZE="2"><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:10pt'>the client does all the rendering job
</SPAN></FONT></FONT><LI><FONT SIZE="2"><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:10pt'>that's why without --use-offscreen-rendering is slower<BR>
</SPAN></FONT></FONT></UL><FONT SIZE="2"><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:10pt'> <BR>
<BR>
any help / reply is highly appreciated<BR>
<BR>
Best Regards,<BR>
chewping<BR>
<BR>
<BR>
<HR ALIGN=CENTER SIZE="3" WIDTH="100%">Date: Fri, 20 Nov 2009 10:57:25 +0800<BR>
From: <a href="weaponfire2005@163.com">weaponfire2005@163.com</a><BR>
To: <a href="lcp81um@msn.com">lcp81um@msn.com</a><BR>
CC: <a href="paraview@paraview.org">paraview@paraview.org</a><BR>
Subject: Re:[Paraview] Off Screen Rendering<BR>
<BR>
hi chew ping：<BR>
The Problem:"Display is not accessible on the server side. Remote rendering will be disabled.", it means that not all server start up X Server, so the server will process the raw data and send all geometry to the client to render.<BR>
The client do all the rendering job, that's the reason why case 2 is so slow, I think.<BR>
When you use off screen, all server processes render the geometry locally , send image to client to composite, so case 1 much faster than case 2.<BR>
I hope this can help you, for I got the same problem before. Good luck.<BR>
<BR>
<BR>
<BR>
<BR>
<BR>
在2009-11-20，"chew ping" <<a href="lcp81um@msn.com">lcp81um@msn.com</a>> 写道：<BR>
</SPAN></FONT></FONT><BLOCKQUOTE><FONT SIZE="2"><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:10pt'>Dear all,<BR>
<BR>
i'm doing parallel rendering using 2 machines (np4), i notice an obvious difference between using offscreen-rendering (faster) and without offscreen-rendering (much slower). i realize this from the timer log:<BR>
<BR>
<BR>
<B>Case 1: with offscreen-rendering<BR>
</B>----------------------------------------------------------<BR>
<BR>
Local Process<BR>
Still Render, 0.666444 seconds<BR>
Execute vtkMPIMoveData id: 519, 0.000199 seconds<BR>
Execute vtkPolyDataMapper id: 311, 0.000106 seconds<BR>
<BR>
<BR>
Server, Process 0<BR>
Execute vtkFileSeriesReader id: 238, 0.645881 seconds<BR>
Execute vtkPVGeometryFilter id: 305, 0.005891 seconds<BR>
Execute vtkPVCacheKeeper id: 516, 7.8e-05 seconds<BR>
Execute vtkMPIMoveData id: 519, 0.000212 seconds<BR>
Execute vtkOrderedCompositeDistributor , 0.000152 seconds<BR>
Execute vtkPolyDataMapper id: 311 , 0.000274 seconds<BR>
<BR>
Server, Process 1<BR>
Execute vtkFileSeriesReader id: 238, 0.000275 seconds<BR>
Execute vtkPVGeometryFilter id: 305, 0.005299 seconds<BR>
Execute vtkPVCacheKeeper id: 516, 7.7e-05 seconds<BR>
Execute vtkMPIMoveData id: 519, 0.000147 seconds<BR>
Execute vtkOrderedCompositeDistributor , 0.000117 seconds<BR>
Execute vtkPolyDataMapper id: 311, 9.9e-05 seconds<BR>
<BR>
Server, Process 2<BR>
Execute vtkFileSeriesReader id: 238, 0.000258 seconds<BR>
Execute vtkPVGeometryFilter id: 305, 0.004765 seconds<BR>
Execute vtkPVCacheKeeper id: 516, 7.7e-05 seconds<BR>
Execute vtkMPIMoveData id: 519, 0.000147 seconds<BR>
Execute vtkOrderedCompositeDistributor , 0.000111 seconds<BR>
Execute vtkPolyDataMapper id: 311, 9.5e-05 seconds<BR>
<BR>
Server, Process 3<BR>
Execute vtkFileSeriesReader id: 238, 0.000352 seconds<BR>
Execute vtkPVGeometryFilter id: 305, 0.005351 seconds<BR>
Execute vtkPVCacheKeeper id: 516, 7.7e-05 seconds<BR>
Execute vtkMPIMoveData id: 519, 0.00016 8 seconds<BR>
Execute vtkOrderedCompositeDistributor , 0.000111 seconds<BR>
Execute vtkPolyDataMapper id: 311, 0.000108 seconds<BR>
<BR>
---------------------------------------------------------------<BR>
<BR>
<BR>
<BR>
<B>Case 2: without offscreen-rendering<BR>
</B>---------------------------------------------------------------<BR>
<BR>
Local Process<BR>
Still Render, 4.86495 seconds<BR>
Execute vtkMPIMoveData id: 520, 2.81566 seconds<BR>
Execute vtkPolyDataMapper id: 312, 0.00012 seconds<BR>
Execute vtkPolyDataMapper id: 148, 7.6e-05 seconds <BR>
<BR>
<BR>
Server, Process 0<BR>
Execute vtkFileSeriesReader id: 239, 0.659133 seconds<BR>
Execute vtkPVGeometryFilter id: 306, 0.026125 seconds<BR>
Execute vtkPVCacheKeeper id: 517, 7.8e-05 seconds<BR>
Execute vtkMPIMoveData id: 520, 2.53214 seconds<BR>
Dataserver gathering to 0, 1.98166 seconds<BR>
Dataserver sending to client, 0.549715 seconds<BR>
Execute vtkOrderedCompositeDistributor , 0.0 00175 seconds<BR>
<BR>
Server, Process 1<BR>
Execute vtkFileSeriesReader id: 239, 0.000446 seconds<BR>
Execute vtkPVGeometryFilter id: 306, 0.026313 seconds<BR>
Execute vtkPVCacheKeeper id: 517, 7.3e-05 seconds<BR>
Execute vtkMPIMoveData id: 520, 0.232435 seconds<BR>
Dataserver gathering to 0, 0.232117 seconds<BR>
Execute vtkOrderedCompositeDistributor , 0.00012 seconds<BR>
<BR>
Server, Process 2<BR>
Execute vtkFileSeriesReader id: 239, 0.000519 seconds<BR>
Execute vtkPVGeometryFilter id: 306, 0.026063 seconds<BR>
Execute vtkPVCacheKeeper id: 517, 7e-05 seconds<BR>
Execute vtkMPIMoveData id: 520, 1.31373 seconds<BR>
Dataserver gathering to 0, 1.31341 seconds<BR>
Execute vtkOrderedCompositeDistributor , 0.000119 seconds<BR>
<BR>
Server, Process 3<BR>
Execute vtkFileSeriesReader id: 239, 0.000459 seconds<BR>
Execute vtkPVGeometryFilter id: 306, 0.004905 seconds<BR>
Execute vtkPVCacheKeeper id: 517, 6.9e-05 seconds<BR>
Execute vtkMPIMoveData id: 520, 0.764289 seconds<BR>
Dataserver gathering to 0, 0.740679 seconds<BR>
Execute vtkOrderedCompositeDistributor , 0.000136 seconds<BR>
<BR>
--------------------------------------------------------------------<BR>
<BR>
<BR>
Unlike Case 2, Case 1 does not show any 'Dataserver gathering to 0' or 'Dataserver sending to client'<BR>
so i guess what makes Case 2 slower is because the vtkMPIMoveData is doing extra thing to move data amongst processes<BR>
<BR>
btw, whenever i run it without -offscreen-rendering, i get this message:<BR>
"Display is not accessible on the server side. Remote rendering will be disabled."<BR>
<BR>
based on what i read from paraview tutorial, what i understand is that the </SPAN></FONT><SPAN STYLE='font-size:10pt'><FONT FACE="Calibri, Verdana, Helvetica, Arial">parallel rendering algorithm allows each process to independently render its partition of the geometry and then composites the partial images together to form the final image. Is this what happened in Case 2 because it has 'Datas erver gathering to 0' or 'Dataserver sending to client'?<BR>
</FONT><FONT FACE="Verdana, Helvetica, Arial"> <BR>
actually what i dont understand is why case 2 is much slower than case 1? <BR>
is it because different 'things' are going on in the processes when offscreen-rendering is on/off?<BR>
<BR>
<BR>
any help / reply is highly appreciated<BR>
<BR>
Best Regards,<BR>
chewping<BR>
<BR>
<BR>
<BR>
<BR>
<BR>
<BR>
<BR>
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<BR>
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<BR>
</FONT></SPAN></FONT></BLOCKQUOTE><FONT SIZE="2"><SPAN STYLE='font-size:10pt'><FONT FACE="Verdana, Helvetica, Arial"><BR>
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**** Kenneth Moreland<BR>
*** Sandia National Laboratories<BR>
*********** <BR>
*** *** *** email: <a href="kmorel@sandia.gov">kmorel@sandia.gov</a><BR>
** *** ** phone: (505) 844-8919<BR>
*** web: <a href="http://www.cs.unm.edu/~kmorel">http://www.cs.unm.edu/~kmorel</a><BR>
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