<div dir="ltr">Dear Simon, <div><br></div><div>I looked the code carefully and evaluated on mac and Linux (I don't think its a system specific issue). I also looked into your code and here what I found: </div><div><br></div><div>* In your example code the desired update rate is set to 25 which is actually on a higher side given the data</div><div>* But the max sampling distance factor is set to 2. </div><div><br></div><div>1) These parameters results in some interesting computation. Old mapper would not use your max sampling distance unless some computation it does cross a threshold.</div><div><br></div><div>2) The new mapper always uses the max sampling distance for clamping and actually if you look at the documentation it should do that. </div><div><br></div><div>Given these two situations, the new mapper use higher sampling distance even when you set it to 2 and therefore runs faster as it tries to match your desired update rate. The new mapper tries to match as well but then it get clamped to maximum of 2 which is not enough to keep up with the desired update rate. Now when you take out this constraint, both of these mappers can go as low as 10 times the sampling distance initially chosen as the desired update rate is bit too high for the rendering. I believe that new mapper is doing the right thing vs the old mapper but I am open for suggestions. </div><div><br></div><div>What I suggest you try these parameters: </div><div>Max sampling distance factor : 4</div><div>Desired update rate: 15 or 20</div><div><br></div><div>Thanks</div><div><br></div><div><br></div><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Nov 17, 2015 at 1:15 AM, Aashish Chaudhary <span dir="ltr"><<a href="mailto:aashish.chaudhary@kitware.com" target="_blank">aashish.chaudhary@kitware.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Dear Simon,<div><br></div><div>Thanks for your example code and data. I used exactly the same code, got master of VTK from today, compiled OpenGL1 and OpenGL2 backends on Ubuntu 14.01 box then for me, the OpenGL2 backend was running much faster and higher resolution than compare to OpenGL1 backend (20 FPS vs 13 FPS). Please look at the screenshots attached. I am referring to the number you are displaying in the program. </div><div><br></div><div>Next, I am going to run the same code on Mac and Windows and see if can reproduce your issue. May be it is windows/driver specific issue. </div></div><div class="HOEnZb"><div class="h5"><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Nov 13, 2015 at 11:02 AM, Aashish Chaudhary <span dir="ltr"><<a href="mailto:aashish.chaudhary@kitware.com" target="_blank">aashish.chaudhary@kitware.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><span>On Fri, Nov 13, 2015 at 10:57 AM, Simon ESNEAULT <span dir="ltr"><<a href="mailto:simon.esneault@gmail.com" target="_blank">simon.esneault@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hello Aashish,<br><br>I've run some quick tests on my computer, and when disabling the automatic adjustment, both of the volume rendering technique seems to deliver the same performance, with some random Fixed sample distance. I will run some more test on the other computer that we've got here, just to be sure. And also on some mac. And report them to you :)<br></div></blockquote><div><br></div></span><div>This is very helpful and sort of confirms my theory the the code in question is the reduction factor computation. The logic is changed between the old mapper and the new mapper. I will look again to make them consistent but it won't be exactly the same since the old mapper code to me was not making the the right choices and was broken for the new mapper. Actually, initially we had the exact same code and it was running into issues since the new mapper was faster and hence breaking some of the assumptions the old mapper was making. </div><span><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><br>Is there something else that I can do to help on this problem ?</div></blockquote><div><br></div></span><div>Not at the moment. You helped a lot, the code and the data is really helpful. I will report back early next week again and will request you to try again. Thanks for your patience. </div><span><font color="#888888"><div><br></div><div>- Aashish </div></font></span><div><div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><span><font color="#888888"><br><br>Simon<br><br></font></span></div><div><div><div class="gmail_extra"><br><div class="gmail_quote">2015-11-12 18:34 GMT+01:00 Aashish Chaudhary <span dir="ltr"><<a href="mailto:aashish.chaudhary@kitware.com" target="_blank">aashish.chaudhary@kitware.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><br><div class="gmail_extra"><br><div class="gmail_quote"><span>On Thu, Nov 12, 2015 at 12:31 PM, Aashish Chaudhary <span dir="ltr"><<a href="mailto:aashish.chaudhary@kitware.com" target="_blank">aashish.chaudhary@kitware.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><br><div class="gmail_extra"><br><div class="gmail_quote"><span>On Thu, Nov 12, 2015 at 12:12 PM, Simon ESNEAULT <span dir="ltr"><<a href="mailto:simon.esneault@gmail.com" target="_blank">simon.esneault@gmail.com</a>></span> wrote:<br></span><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hello Aashish,<div><br></div><span><div>Sorry for the late reply, I was busy last week.<br><br>Thanks for the update, and your work on this topic.</div><div>Yes I have seen that your change have been merged concerning the ReductionFactor. Nevertheless, I am still getting a smaller frame rate with the new backend. To highlight this, please find attached a very simple application that loads a volume (<a href="https://www.dropbox.com/s/ptqwi0ebv75kt35/volume.zip" target="_blank">https://www.dropbox.com/s/ptqwi0ebv75kt35/volume.zip</a>) and does volume rendering while displaying the frame rate. This is pretty much what we show to the user in our application, and in this condition, on my machine the FPS are around <a href="http://picpaste.com/pics/Bench-OGL1.1446644265.png" target="_blank">25 with the opengl1 backend</a>, and <a href="http://picpaste.com/pics/Bench-OGL2.1446644630.png" target="_blank">15 with the new backend</a>, from this week VTK master</div><div>It is very simple to test, just need change the VTK_DIR to an OpenGL1 or OpenGL2 build, and place the volume.mhd and raw in the execution path.<br>Also you will find attached a small text file that summarizes the test that have been done here.<br></div></span></div></blockquote><div><br></div><div>No problem, thanks for the update. Please see my comments below: </div><span><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><br>I think the real reason why it appears slower with the OGL2 version is that we try to have control on the "MaximalImageSampleDistance". If I remove the line l_gpu_mapper->SetMaximumImageSampleDistance( 2. ); I get the same frame rate with each backend. BUT, the new backend does decimate a lot more the volume, leading to a very blurred image during rendering, and that's not what we want :/</div></div></blockquote><div><br></div></span><div>Aha, this is very useful since this parameters does affecting the reduction factor. I will try your code; one quick question when the new backend decimates a lot (by removing the SetMaximumImageSampleDistance), does it get any faster than the old version? I am going to try it on my Mac and Linux laptop and report back (mostly tomorrow since I am away today). </div><span><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><br></div></div></blockquote></span></div></div></div></blockquote><div><br></div></span><div>Never mind, I see that you have that in your result file. It seems it does get faster but more blurry. Would it be possible for you to do one more test? Can you set a fix sample distance (pick any) for new and the old mapper and set AutoAdjustSampleDistance to OFF and capture some performance numbers? In that way we know exactly if something more fundamental is causing the slowness. The whole reduction factor math is based on approximate stuff so that will vary between two mappers. </div><span><font color="#888888"><div><br></div><div>- Aashish</div></font></span><div><div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><span><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div>Again, thanks for paying attention to this problem, I hope this little application and test case can help you to adjust the parameters...</div></div></blockquote><div><br></div></span><div>Thanks for your help. I am glad you are testing my latest changes. </div><div><br></div><div>- Best, Aashish </div><div><div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><span><font color="#888888"><br><br>Simon<br></font></span><br>PS : I did not get a chance to check the difference on Paraview, but I believe the result will be the same as the attached example is really simple.</div></div><div><div><div class="gmail_extra"><br><div class="gmail_quote">2015-11-03 19:44 GMT+01:00 Aashish Chaudhary <span dir="ltr"><<a href="mailto:aashish.chaudhary@kitware.com" target="_blank">aashish.chaudhary@kitware.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi Simon, <div><br></div><div>the branch has been merged into VTK master. I am not sure when Paraview is going to update the VTK, but you can do it manually if needed. We are also going to run our bench marking again to be sure since recently lot many changes went into the VTK / volume rendering. Please feel free to ping me again if it does not solve your issue. </div><div><br></div><div>Looking forward to your feedback. </div><span><font color="#888888"><div><br></div><div>- Aashish</div></font></span></div><div><div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Nov 2, 2015 at 8:02 AM, Aashish Chaudhary <span dir="ltr"><<a href="mailto:aashish.chaudhary@kitware.com" target="_blank">aashish.chaudhary@kitware.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi Simon, <div><br></div><div>I found the reason behind the appeared performance you were getting. We have this code in volume rendering that when you interact changes the sampling distance and in the newer code we were too conservative compare to the last version. That's why you were getting better quality when you move your mouse but lower frame rates. I pushed a branch in VTK to address the issue. Would it be possible for you to build Paraview with VTK master? It may take 3-4 days or longer for Paraview's VTK to get updated. </div><div><br></div><div>Thanks,</div><div>Aashish</div></div><div><div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Oct 28, 2015 at 11:59 AM, Aashish Chaudhary <span dir="ltr"><<a href="mailto:aashish.chaudhary@kitware.com" target="_blank">aashish.chaudhary@kitware.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi Simon, <div><br></div><div>I am just finishing up a ParaView5 related parallel volume rendering bug (pushing a branch today to VTK). This is next on my list. </div><span><font color="#888888"><div><br></div><div>- Aashish</div></font></span></div><div><div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Oct 28, 2015 at 11:57 AM, Simon ESNEAULT <span dir="ltr"><<a href="mailto:simon.esneault@gmail.com" target="_blank">simon.esneault@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hello Aashish<br><br>Did you get a chance to try to load the dataset on Windows ? <br>Can I do anything to help you investigate ? Should I feel a bug, that may act as a reminder ?<br>Have a nice day<span><font color="#888888"><br>Simon</font></span><div><div><br><div class="gmail_extra"><br><div class="gmail_quote">2015-10-27 18:26 GMT+01:00 Aashish Chaudhary <span dir="ltr"><<a href="mailto:aashish.chaudhary@kitware.com" target="_blank">aashish.chaudhary@kitware.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Thanks Simon. This is really strange since we are not seeing it on Mac and Linux (but both has dedicated cards). <div><br></div><div>I will look into it soon. </div><span><font color="#888888"><div><br></div><div>- aashish</div></font></span></div><div><div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Oct 27, 2015 at 1:03 PM, Simon ESNEAULT <span dir="ltr"><<a href="mailto:simon.esneault@gmail.com" target="_blank">simon.esneault@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Ok, thank you very much fort digging into this.<br>I've done some test and I believe I can see a similar slowdown happening on OSX, with a MacBook pro retina 13" from 2013, Intel Iris 5100 graphics.<br>Good luck in the investigation, I you need more details, do not hesitate to ask<span><font color="#888888"><br>Simon</font></span></div><div><div><div class="gmail_extra"><br><div class="gmail_quote">2015-10-27 17:37 GMT+01:00 Aashish Chaudhary <span dir="ltr"><<a href="mailto:aashish.chaudhary@kitware.com" target="_blank">aashish.chaudhary@kitware.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Ah, thanks. I will get back to you on this since on Linux I don't any issue so it has to be Windows specific thing. <span><font color="#888888"><div><br></div><div>- Aashish</div></font></span></div><div><div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Oct 27, 2015 at 10:36 AM, Simon ESNEAULT <span dir="ltr"><<a href="mailto:simon.esneault@gmail.com" target="_blank">simon.esneault@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">I tried with that one from yesterday and today's version (4.4.0-209-gc399648)<br><br>Thanks,<br>Simon</div><div><div><div class="gmail_extra"><br><div class="gmail_quote">2015-10-27 15:19 GMT+01:00 Aashish Chaudhary <span dir="ltr"><<a href="mailto:aashish.chaudhary@kitware.com" target="_blank">aashish.chaudhary@kitware.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Thanks. <div><br></div><div>And when did you download this version? <span style="font-size:16px">ParaView-latest-Qt4-OpenGL2-</span><span style="font-size:16px">Windows-64bit.exe</span></div><div><span style="font-size:16px"><br></span></div><div><span style="font-size:16px">Thanks,</span></div><div><span style="font-size:16px">Aashish<br></span><div><div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Oct 27, 2015 at 10:17 AM, Simon ESNEAULT <span dir="ltr"><<a href="mailto:simon.esneault@gmail.com" target="_blank">simon.esneault@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr">Yes, I tried with and without the shading. Without shading enabled, the new Opengl2 is also slower when zoomed in (in the described condition). With shading enabled, the difference in speed between the two version seems even bigger.<br>I got the version from the nightly build download section of paraview website (it is still available). And I've just tried with that one labeled "ParaView-latest-Qt4-OpenGL2-Windows-64bit.exe" with the same results.<br><br>About the FPS, it is difficult to give an exact number, because it depends of the condition (zoomed or not etc...) but yes, this is the idea.<br>In our software, I've exposed the frame rate using this example : <a href="http://www.vtk.org/Wiki/VTK/Examples/Cxx/Utilities/FrameRate" target="_blank">http://www.vtk.org/Wiki/VTK/Examples/Cxx/Utilities/FrameRate</a><br>And the frame rate is around 15/20 for the first backend, and around 6/8 for the new backend, on the same dataset (the one provided for example), with the same mapper parameters<br><br>Thanks<span><font color="#888888"><br>Simon<br><br></font></span></div><div><div><div class="gmail_extra"><br><div class="gmail_quote">2015-10-27 14:48 GMT+01:00 Aashish Chaudhary <span dir="ltr"><<a href="mailto:aashish.chaudhary@kitware.com" target="_blank">aashish.chaudhary@kitware.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr">Hi Simon,<div><br></div><div>This is helpful but just missing few more bits:</div><div><br></div><div>1) Did you try without the shading and see how the performance compares?</div><div><br></div><div>2) <span style="font-size:16px">ParaView 4.4.0-193-gec96423 --> Where did you get this one from (ParaView download page or did you built yourself?)</span></div><div><span style="font-size:16px"><br></span></div><div><span style="font-size:16px">Also, so on your system the old mapper is running 30FPS and the new one at 15-20 FPS as per your summary. </span></div><div><span style="font-size:16px"><br></span></div><div><span style="font-size:16px">Thanks,</span></div><div><span style="font-size:16px">- Aashish</span></div><div><span style="font-size:16px"><br></span></div></div><div><div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Oct 27, 2015 at 9:43 AM, Simon ESNEAULT <span dir="ltr"><<a href="mailto:simon.esneault@gmail.com" target="_blank">simon.esneault@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr">Hello Aashish,<br><div><br>Sorry for the late answer, I was busy this morning.</div><div>Thanks for testing with the DataSet.<br>I agree the performance is still quite good with the new backend, and I also get something like 15/20 fps on windows on an HD screen. But when compared to the old one, and in some condition (when zoomed especially), it looks really slower to me<br>The two tested version are :<br>- ParaView 4.4.0 64 bits final version for the old backend<br>- ParaView 4.4.0-193-gec96423 64 bits, for the OpenGL2 backend.</div><div>on a windows 7 box, Xeon E3-1220 v3 CPU, 16GB ram and Nvidia Quadro K420<br><br>To highlight the difference, here is what I do :</div><div>- Launch both version on the same computer at the same time</div><div>- Load the above dataset on each</div><div>- Select volume rendering</div><div>- Adjust the transfer function data range to [100-750] (the default "Cool to Warm" is fine)</div><div>- Set the view direction to +Y</div><div>- Adjust the Y of the camera position to -300</div><div><br>And start interacting ...<br>Dunno if there is an easy way to print out the Frame Rate in Paraview, but the new version seems really twice slower in these conditions... We can see it does not scale in the same way, the old backend seems more aggressive on the image sample reduction, hence the interactivity is better.<br>Shading enable or not does not change much<br><br>I'm aware of the DesiredUpdateRate thing, we use to play with this with the old backend to fine tune the interactivity, although what's really inside was never clear to me<br><br>I hope that there is enough information for you to reproduce this, do not hesitate to ask for some more information.<br><br>Thanks a lot for your help<span><font color="#888888"><br>Simon</font></span></div><div><br></div></div><div><div><div class="gmail_extra"><br><div class="gmail_quote">2015-10-27 14:10 GMT+01:00 Aashish Chaudhary <span dir="ltr"><<a href="mailto:aashish.chaudhary@kitware.com" target="_blank">aashish.chaudhary@kitware.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr">Dear Simon, <div><br></div><div>Checking again. Wondering if you can provide some more detail on the binary you are using and whether or not without shading the rendering performance comparable to older version. </div><div><br></div><div>Thanks,</div><div><br></div></div><div><div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Oct 26, 2015 at 3:12 PM, Aashish Chaudhary <span dir="ltr"><<a href="mailto:aashish.chaudhary@kitware.com" target="_blank">aashish.chaudhary@kitware.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr"><span><span style="font-size:16px">Simon, </span><div style="font-size:16px"><br></div><div style="font-size:16px">I used your dataset on paraview master as of today on my Linux box running Ubuntu 14.04 and NVIDA Quadro card and I am getting about 15-20 FPS with shading on with 1920x1080 resolution. </div></span><span style="font-size:16px"><span><div><br></div><div>Are you on the proper 4.4 or using RC1/RC2? I checked the shading performance fix was in 4.4 but not in RC's. I don't have access to Windows box right away but I will try there too. </div><div><br></div></span><div>NOTE: You might get multiple emails because of the attachment size issue. Sorry about that. </div><div><br></div></span><div style="font-size:16px">Thanks,</div></div><div><div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Oct 26, 2015 at 2:45 PM, Aashish Chaudhary <span dir="ltr"><<a href="mailto:aashish.chaudhary@kitware.com" target="_blank">aashish.chaudhary@kitware.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr"><br><div class="gmail_extra"><br><div class="gmail_quote"><span>On Mon, Oct 26, 2015 at 2:13 PM, Simon ESNEAULT <span dir="ltr"><<a href="mailto:simon.esneault@gmail.com" target="_blank">simon.esneault@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr">Hello Aashish,<br><br>Thanks for the quick answer<br>We are using a vtkImageData, 512x512x591 with short element (you can find the dataset here : <a href="https://www.dropbox.com/s/ptqwi0ebv75kt35/volume.zip" target="_blank">https://www.dropbox.com/s/ptqwi0ebv75kt35/volume.zip</a>). So I think it's all about GPU volume raycast mapper.<br>The new mapper does bring low resolution, but when compared to the old one, it seems less "low resolution" during interaction than the old one<br></div></blockquote><div><br></div></span><div>Right, so that's why its not a exact comparison. What happens is that depending on what is interactive, (you can set the desired update rate in VTK, not exposed in ParaView I believe), it will do interactive but with higher resolution (smaller sample distance). If they both have the same sample distance, then the new mapper should out perform the old one, however, there is another thing we need to consider here which is shading. </div><span><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr">Shading is enabled, gradient opacity disabled<br></div></blockquote><div><br></div></span><div>Can you disable the shading and see if now they both (opengl1 and 2) equally better? We already pushed a fix for it but not sure if that you have in your build. </div><span><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr"><br>Don't know if you need a minimal example, but I believe the GPURenderDemo used with this dataset is enough to highlight the slow down.<br></div></blockquote><div><br></div></span><div>Yes, I will use this dataset. Thanks. </div><div><div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr"><br>Thanks<span><font color="#888888"><br>Simon<br><br></font></span></div><div><div><div class="gmail_extra"><br><div class="gmail_quote">2015-10-26 18:57 GMT+01:00 Aashish Chaudhary <span dir="ltr"><<a href="mailto:aashish.chaudhary@kitware.com" target="_blank">aashish.chaudhary@kitware.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr">Also, <div><br></div><div>Do you have shading enabled? We fixed a bug with shading that was causing the slow performance a while back. I don't remember if that was included in 4.4 or not ( I can check ). </div><span><font color="#888888"><div><br></div><div>- Aashish</div></font></span></div><div><div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Oct 26, 2015 at 1:53 PM, Aashish Chaudhary <span dir="ltr"><<a href="mailto:aashish.chaudhary@kitware.com" target="_blank">aashish.chaudhary@kitware.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr">Simon, <div><br></div><div>What kind of dataset you are using? Depending on the data type you might be using</div><div>the GPU one or the unstructured renderer. The performance we measured is related to the GPU ray cast mapper</div><div>and will apply only to the vtkImageData inputs. </div><div><br></div><div>Also, helpful would be is if you can tell if the new mapper is bringing low resolution when you interact with the volume (and whether or not it happens with old mapper). </div><div><br></div><div>Thanks,</div><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote"><div><div>On Mon, Oct 26, 2015 at 1:47 PM, Simon ESNEAULT <span dir="ltr"><<a href="mailto:simon.esneault@gmail.com" target="_blank">simon.esneault@gmail.com</a>></span> wrote:<br></div></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div><div><div dir="ltr">Hi All,<br><br>We are trying to make the switch to the new OpenGL2 backend for our application, and although the switch was easy (thanks for not breaking the API ;) ), we can see a significant slowdown on the GPU volume rendering part, especially during interaction. Typically we dropped from 15/20 fps to 7/8 fps, on the same machine (Win32, Nvidia Quadro K420), with the same code around.<div><br>This slow down can be seen in ParaView, if you compare the latest 4.4 OpenGL2 build with the classic 4.4 build while volume rendering a big enough volume (512^3)<br></div><div><br>The blog post here<br><a href="http://www.kitware.com/blog/home/post/976" target="_blank">http://www.kitware.com/blog/home/post/976</a><br>claims that the new GPU volume rendering implementation should be faster than the old one, is there some more detailed explanation somewhere ? Are there some important parameters that can make the difference ?<br><br>Thanks, <br><br>Simon</div><div><br></div><div>PS : The polygonal rendering seems a lot faster with the new backend !<span><font color="#888888"><br><div><br></div>-- <br><div><div dir="ltr"><div>------------------------------------------------------------------<br>Simon Esneault<div>Rennes, France<br>------------------------------------------------------------------</div></div></div></div>
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</div></div></blockquote></div><br><br clear="all"><div><br></div>-- <br><div><div dir="ltr"><font face="trebuchet ms, sans-serif"><i>| Aashish Chaudhary <br>| Technical Leader <br>| Kitware Inc. <br></i></font><div><i><font face="trebuchet ms, sans-serif">| </font><a href="http://www.kitware.com/company/team/chaudhary.html" target="_blank">http://www.kitware.com/company/team/chaudhary.html</a></i></div></div></div>
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</div></div></blockquote></div><br><br clear="all"><div><br></div>-- <br><div><div dir="ltr"><font face="trebuchet ms, sans-serif"><i>| Aashish Chaudhary <br>| Technical Leader <br>| Kitware Inc. <br></i></font><div><i><font face="trebuchet ms, sans-serif">| </font><a href="http://www.kitware.com/company/team/chaudhary.html" target="_blank">http://www.kitware.com/company/team/chaudhary.html</a></i></div></div></div>
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</div></div></blockquote></div><br><br clear="all"><div><br></div>-- <br><div><div dir="ltr"><font face="trebuchet ms, sans-serif"><i>| Aashish Chaudhary <br>| Technical Leader <br>| Kitware Inc. <br></i></font><div><i><font face="trebuchet ms, sans-serif">| </font><a href="http://www.kitware.com/company/team/chaudhary.html" target="_blank">http://www.kitware.com/company/team/chaudhary.html</a></i></div></div></div>
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</blockquote></div><br><br clear="all"><div><br></div>-- <br><div><div dir="ltr"><font face="trebuchet ms, sans-serif"><i>| Aashish Chaudhary <br>| Technical Leader <br>| Kitware Inc. <br></i></font><div><i><font face="trebuchet ms, sans-serif">| </font><a href="http://www.kitware.com/company/team/chaudhary.html" target="_blank">http://www.kitware.com/company/team/chaudhary.html</a></i></div></div></div>
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</div></div></blockquote></div><br><br clear="all"><div><br></div>-- <br><div><div dir="ltr"><font face="trebuchet ms, sans-serif"><i>| Aashish Chaudhary <br>| Technical Leader <br>| Kitware Inc. <br></i></font><div><i><font face="trebuchet ms, sans-serif">| </font><a href="http://www.kitware.com/company/team/chaudhary.html" target="_blank">http://www.kitware.com/company/team/chaudhary.html</a></i></div></div></div>
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</div></div></blockquote></div></div></div><div><div><br><br clear="all"><div><br></div>-- <br><div><div dir="ltr"><font face="trebuchet ms, sans-serif"><i>| Aashish Chaudhary <br>| Technical Leader <br>| Kitware Inc. <br></i></font><div><i><font face="trebuchet ms, sans-serif">| </font><a href="http://www.kitware.com/company/team/chaudhary.html" target="_blank">http://www.kitware.com/company/team/chaudhary.html</a></i></div></div></div>
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</blockquote></div></div></div><div><div><br><br clear="all"><div><br></div>-- <br><div><div dir="ltr"><font face="trebuchet ms, sans-serif"><i>| Aashish Chaudhary <br>| Technical Leader <br>| Kitware Inc. <br></i></font><div><i><font face="trebuchet ms, sans-serif">| </font><a href="http://www.kitware.com/company/team/chaudhary.html" target="_blank">http://www.kitware.com/company/team/chaudhary.html</a></i></div></div></div>
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</blockquote></div><br><br clear="all"><div><br></div>-- <br><div><div dir="ltr"><div>------------------------------------------------------------------<br>Simon Esneault<div>Rennes, France<br>------------------------------------------------------------------</div></div></div></div>
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</div></div></blockquote></div></div></div><div><div><br><br clear="all"><div><br></div>-- <br><div><div dir="ltr"><font face="trebuchet ms, sans-serif"><i>| Aashish Chaudhary <br>| Technical Leader <br>| Kitware Inc. <br></i></font><div><i><font face="trebuchet ms, sans-serif">| </font><a href="http://www.kitware.com/company/team/chaudhary.html" target="_blank">http://www.kitware.com/company/team/chaudhary.html</a></i></div></div></div>
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</blockquote></div><br><br clear="all"><div><br></div>-- <br><div><div dir="ltr"><font face="trebuchet ms, sans-serif"><i>| Aashish Chaudhary <br>| Technical Leader <br>| Kitware Inc. <br></i></font><div><i><font face="trebuchet ms, sans-serif">| </font><a href="http://www.kitware.com/company/team/chaudhary.html" target="_blank">http://www.kitware.com/company/team/chaudhary.html</a></i></div></div></div>
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</div></div></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature"><div dir="ltr"><font face="trebuchet ms, sans-serif"><i>| Aashish Chaudhary <br>| Technical Leader <br>| Kitware Inc. <br></i></font><div><i><font face="trebuchet ms, sans-serif">| </font><a href="http://www.kitware.com/company/team/chaudhary.html" target="_blank">http://www.kitware.com/company/team/chaudhary.html</a></i></div></div></div>
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